DE102020214603A1 - Process for manufacturing a component - Google Patents

Abstract

The invention relates to a method for producing a component (1), in which a digital model (2) with two bearing points (3, 4, 5) spaced apart from one another is provided, the bearing points (3, 4, 5) being formed by means of a material component (6 , 7, 8, 11). Furthermore, a load (9) acting on the model (2) is simulated and a stress analysis is carried out on the material component (6, 7, 8, 11). An algorithm based on the results of the stress analysis is then applied, whereby load paths between the bearing points (3, 4, 5) are determined in the material component (6, 7, 8, 11). This is followed by an iterative simulation of removing low-stress material portions (10) of the material component (6, 7, 8, 11). Furthermore, based on the model (2) reduced by the low-stress material portions (10), a digital component model is generated and made available for manufacturing the component of a manufacturing unit.

Description

The invention relates to a method for producing a particularly fiber-reinforced component.

Methods for constructing mechanical components are known from the prior art, in which a volume of the mechanical component is discretized into a large number of cells and a mechanical stress in the respective cell is determined under load. Furthermore, various optimization methods are known, which can be generated by an automated evaluation of the discrete cells, fiber orientations or component volumes with regard to optimal material utilization. With regard to additive or generative manufacturing processes, in which a fiber and a material jacket encasing the fiber are coextruded together, these days, i.e. with conventional structural-mechanical optimization tools, cannot be processed in an optimal manner. Because an anisotopic material structure, which goes hand in hand with the fiber material, cannot yet be exploited in a topology optimization in an expedient manner. For a conventional topology optimization, it is also known from the prior art that an isotropic block of material is built up in a simulative manner between load introduction and load transfer elements. A stress analysis is then carried out, for example using FEM software (FEM: Finite Element Method), and stress-free or low-stress isotropic material is removed. At the end of such an optimization, thin branched bridges typically remain between the load introduction and load transfer elements, which transmit defined loads in an optimal arrangement. However, a geometric or positional arrangement of these branched bridges leads to a component geometry that is often difficult to produce, which is why such an optimization method is used almost exclusively for components that are to be manufactured additively or generatively.

However, the mere application of this conventional topology optimization to anisotropic materials does not lead to desirable results, since three-dimensional fiber-reinforced additive or generative manufacturing is subject to greater limitations than conventional (fiber-free) additive or generative manufacturing. Furthermore, a reduction of the anisotropic material block, in which different material properties, in particular strength properties, are present along the spatial directions, would most likely not lead to a particularly advantageous final design of the component to be produced accordingly. Because it is to be expected that the branched bridges form primarily along the spatial direction along which the anisotropic block of material has the most appropriate strength properties.

Another optimization method known from the prior art is parameter geometry optimization, parameters or variables for specific lengths and sizes being specified during modeling of a CAD model (CAD: computer-aided design) of the component. A table-supported optimization tool records specified parameters on the CAD model and determines external properties, such as an expected total mass of the component to be produced using the CAD model and/or maximum stresses to be expected and/or deformations to be expected in that component. The assigned parameters are then iteratively improved using various optimization algorithms, with the aim, for example, of achieving the lowest possible total mass while at the same time complying with voltage limits. In this case, however, the efficiency of this optimization method already depends to a large extent on the parameters selected by the (human) user and the CAD model of the component also generated by the human user.

The object of the present invention is to create a particularly efficient manufacturing method for a particularly fiber-reinforced component.

This object is achieved by a method with the features specified in claim 1.

According to the invention, a method for producing a component is proposed, the method particularly relating to the production of a fiber-reinforced component. In a step S1 of the method, a digital model with two bearing points spaced apart from one another is provided. For example, a first of the support points is provided as a load application point, with another of the support points being provided as a load output point. In step S1, the support points, ie the load application point and the load output point, are further connected by means of a material component. In step S1 only the mounting points and the material components are provided, so that the digital model initially characterizes the component to be manufactured only by the mounting points and the material components and other geometric and/or positional boundary conditions are initially ignored in step S1.

In a further step S2, a load acting on the model is simulated and a stress analysis of the material component is carried out. For example, a force is simulated that acts on at least one of the bearing points, for example at the load application point, with this force then being passed by means of the material component to another of the bearing points, for example to the load transfer point, as a result of which mechanical stresses occur inside the material component. These mechanical stresses occurring inside the material component are the subject of the stress analysis.

The method also has a step S3, in which the digital model is subjected to an algorithm. In other words, in step S3 the algorithm is applied to the model, this algorithm being based on the results of the stress analysis. In this way, load paths between the bearing points are determined or identified in the material component. Due to the application of the algorithm to the model, in particular to the material component, both high-stress material parts of the material component and low-stress, in particular stress-free, material parts of the material component result.

The high-stress and low-stress material portions of the material component are the subject of a further step S4 of the method for producing the component, with a removal of low-stress material portions being simulated in this step S4. In other words, the digital model of the component to be produced, in particular the material component generated by simulation, is reduced by the low-stress material portions, with the high-stress material portions remaining in the digital model, ie in the material component. This is because the load paths, which have been determined or identified by means of the stress analysis in step S3 of the method, induce the mechanical stresses in the material component(s), with the load paths and the high-stress material parts of the material component being associated with one another, for example coinciding.

In a further step S5, a digital component model is generated, this digital component model being based on the digital model reduced by the low-stress material portions. This means that in step S5 the digital component model is generated from the digital model, the bearing points and the material components reduced by the low-stress material portions being used to generate the digital component model. In other words, the digital component model emerges from the digital model through the simulative removal (step S4) of the low-stress material portions.

The digital component model is provided in a step S6 of the method, so that the component can be produced using the digital component model. For example, in step S6 the digital component model is delivered to a production unit, the production unit being designed to produce the component using the digital component model. The manufacturing unit is designed in particular to produce the component by means of an additive or generative manufacturing process, for example 3D printing.

A particularly efficient method for producing a component is thus created, with advantageous material orientation distributions being found in the material component through the stress analysis and through the algorithm, which are carried out iteratively in particular with the simulative removal of the low-stress material portions. This ultimately results in the digital component model, which leads to a particularly light and at the same time particularly stable component. Using the algorithm, which can in particular be designed to be evolutionary or based on stress gradients, an external criterion for a better design of the component or component model is merely a stiffness, i.e. a deformation response to the load acting on the model, with a smaller deformation being preferable to a larger deformation .

With this method, it is to be expected in an advantageous manner that bridges (material bridges) are formed between the bearing points, which correspond to the load, by the simulative removal of the low-stress material portions from the material component. This means that these bridges are able to take up and/or transfer the load between the storage points. A lightweight construction concept is taken into account in particular, since these bridges are only reduced by the simulative removal.

In a first development of the method, the material component is simulated in the model as an initially fiber-free matrix material. This matrix material has in particular anisotropic material properties, in particular strength properties. Consequently, in step S4 of the method, a removal of low-stress portions of the matrix material, ie low-stress matrix material portions, is simulated. Accordingly, the method can be carried out particularly simply and/or with little effort, since the limitations associated with a fiber strand are initially not taken into account ben. However, in this context it cannot be ruled out that a fiber or a fiber strand is added to the initially fiber-free matrix material, in particular in a simulation, for example between step S4 and step S5.

As an alternative to the first development of the method, it can be provided in a second development of the method that the material component is simulated as a fiber strand in the model. The fiber strand has at least one individual fiber and a matrix material sheath, the at least one individual fiber being sheathed by the matrix material sheath. Consequently, in step S4 of the method, there is a simulative removal of low-tension portions of the fiber strand, that is to say of low-tension fiber strand portions. This results in the advantage that the anisotropic material properties of the fiber and the, for example, isotropic material properties of the matrix material are included to generate the digital component model, so that the bridges or material bridges between the bearing points are formed or simulated in a particularly advantageous manner. Ultimately, a particularly preferred ratio between a component mass and a component strength or a component stability then results for the component.

It has also proven to be advantageous if, in the method after step S4, for example in a step S4a, the material component in the model is supplemented by a fiber strand connecting the bearing points. This fiber strand, which is supplemented in step S4a, can, for example, be added to the material component designed as the initially fiber-free matrix material. The fiber strand that is added in step S4a can alternatively be added to the material component formed as the fiber strand. In other words, the fiber strand that is added to the model in step S4a forms the first fiber strand that is added to the model of the component to be manufactured in relation to the material component simulated as the initially fiber-free matrix material. Regarding the material component that is simulated as the fiber strand, since the material component created in step S1 forms the first fiber strand, the fiber strand added to the model of the component to be manufactured in step S4a forms the second fiber strand. In this way, particularly advantageous load paths can be generated between the bearing points, which is associated with a particularly advantageous stability of the fiber-reinforced component that is ultimately produced.

If the further fiber strand is added to the material component designed as the fiber strand in the method in step S4a, it is also preferred that step S4a, i.e. the addition of the further fiber strand, and a removal of low-stress portions of this fiber strand is simulated iteratively. This means that step S4a may be carried out multiple times, depending on whether repeated execution of step S4a leads to a better design of the component to be manufactured. For this purpose it can be provided, for example, that after step S4a has been run through for the first time, a stress analysis of the material component is carried out, then step S4a is carried out again and a stress analysis is carried out again, with the results of these stress analyzes being compared. If there has been no improvement in the results of the stress analysis due to performing step S4a again, it is provided in particular that the fiber strand added in step S4a performed previously is removed from the model and the steps of the method following step S4a are performed without step S4a is run through again. In this way, a particularly advantageous structure of the fiber strands results for the model and consequently for the component to be manufactured, so that the relationship between the component mass and the component stability or strength is again improved.

In a further advantageous embodiment of the method, it is provided that after step S4 has been run through for the first time, an iteration SI starting with step S2 and ending before step S5 is carried out, the iteration SI comprising a step S4b in which, after step S4, the respective results of the current stress analysis can be compared with the results of the previous stress analysis. If a predetermined or predeterminable result improvement has not occurred, step S4 is followed by step S5. This means that steps S2, S3, S4 and in particular step S4a and in particular step S4b are carried out at least twice in succession when the method is carried out. In particular, these aforementioned steps are run through whenever there is an improvement in the results of the respective stress analysis. Because an iteration means that an improvement is approached, with it being checked at least once whether the simulative removal of the low-stress material portions results in improved stress properties in the material component. Such a procedure again advantageously leads to a particularly advantageously designed component, since conditions of the material component that arise due to the initial removal of low-stress portions are included in a new stress analysis, so that ultimately particularly advantageous material bridges can be created between the bearing points.

According to a further advantageous embodiment of the method, the respective fiber strand is assigned a set of boundary conditions with at least one boundary condition, whereby a spatial arrangement of the corresponding fiber strand is based on the set of boundary conditions when simulating the respective fiber strand. For example, by means of the set of boundary conditions in the model, the respective fiber strand can be simulated with a meandering, screwed, (multiple) kinked etc. course between the bearing points. For example, the finally manufactured component is given a particularly high tensile strength in relation to several spatial directions.

For example, the constraint set is assigned to the material component when it is simulated as the fiber strand. Furthermore, the set of boundary conditions can be assigned to the fiber strand that is generated or simulated in step S4a. As a result, provision can be made for the material component in the model to run between the support points based on the set of boundary conditions. Alternatively or additionally, it can be provided that the fiber strand, which is added in step S4a, runs between the bearing points based on the set of boundary conditions.

In this context, it has proven to be particularly advantageous if at least one support point between the support points is defined in the model via a boundary condition of the set of boundary conditions, with this support point being connected to the fiber strand when the respective fiber strand is simulated. In addition to the support points, i.e. in addition to the load application point and the load transfer point, the additional support point or more additional support points are arranged in the model in a simulative manner, so that, for example, the material component, which is designed as the fiber strand, between the support points with the support point or connected to the bases. In an analogous manner, the fiber strand added in step S4a of the method is connected between the storage points to the support point or to the support points. Accordingly, the respective fiber strand runs from one of the storage points via the support point or via the support points to another of the storage points. In this case, the respective fiber strand is connected both to the storage points and to the support points. This means that in the finished component the respective fiber strand is non-positively, positively and/or materially connected both to the bearing points and to the support point or at least some of the support points.

For example, when constructing or simulating the component or the component model, the set of boundary conditions can be used to address a predefined restriction with regard to an external geometry of the component. Accordingly, it can be provided that the respective support point is defined by a (human) operator of the method. Alternatively or additionally, it can be provided that the respective support point is randomly arranged between the storage points, at least within a corridor between the storage points.

According to a further advantageous embodiment of the method, it can be provided that at least one further bearing point different from the two bearing points is defined in the model via a further boundary condition of the boundary condition set, with the bearing point being connected to the fiber strand when the respective fiber strand is simulated. This means that the method can be used to generate or produce a component and in particular to simulate it beforehand using the digital model, which component has a further bearing point or more further bearing points beyond the load introduction point and the load discharge point. In particular, at least the one additional (e.g. third) bearing point is fixed or defined, which can for example form an additional load application point or an additional load transfer point. In this context it is conceivable that the respective fiber strand is arranged between the bearing points in such a way that the fiber strand runs directly between a first bearing point and a last bearing point, for example the third bearing point. In addition, it is conceivable that the fiber strand runs from the first of the storage points via further storage points and finally to the last of the storage points. A type of star topology is also conceivable, with this star topology being able to be represented by a single fiber strand or by a multiplicity of fiber strands. This applies analogously, alternatively or additionally, to the connection of the support points by means of a single fiber strand or by means of the multiplicity of fiber strands.

In a further advantageous embodiment of the method, a reinforcing fiber strand is provided, which is simulated in the model, with this reinforcing fiber strand and the respective fiber strand being arranged at an angle to one another. This means that the reinforcing fiber strand designed or simulated as the reinforcing fiber strand and at least one of the previously described NEN fiber strands are at least partially arranged obliquely to each other. For example, it can be provided that the reinforcing fiber strand and the corresponding one of the previously described fiber strands are arranged other than parallel to one another. This has the advantage that a weak material load-bearing capacity of a fiber-reinforced plastic composite is stabilized transversely to the respective fiber strand by the reinforcing fiber strand.

In an alternative or additional configuration, it can be provided that the reinforcing fiber strand or a further reinforcing fiber strand is formed by one of the fiber strands described above. Accordingly, the reinforcing fiber strand is arranged, for example, parallel to the corresponding one of the previously described fiber strands. In this case, this reinforcing fiber strand has in particular the same connection points as the corresponding fiber strands described above. Consequently, the reinforcing fiber strand and the corresponding one of the previously described fiber strands can be arranged parallel to one another, at least in sections.

Existing material bridges are further reinforced by such a reinforcing fiber strand, as a result of which these existing material bridges are made particularly stable, for example in order to absorb the load acting on the component in a particularly efficient manner and/or to transfer it between the bearing points or support points.

As already explained, the reinforcing fiber strand is a fiber strand which, for example, can be the same as one of the fiber strands described above. Consequently, in the method according to a further advantageous embodiment it is provided that the fiber strand to which the set of boundary conditions is assigned is the reinforcing fiber strand. According to this embodiment, it is provided in particular that the set of boundary conditions, ie one or more boundary conditions, is/are assigned to the reinforcing fiber strand so that the reinforcing fiber strand is simulated in the model based on the boundary condition set. As a result, the reinforcing fiber strand is used in a particularly versatile and flexible manner to achieve a desired target design of the component, in that this reinforcing fiber strand fulfills a large number of functions in the finished component.

According to a further advantageous embodiment of the method--for example in, before or after step S1--a multiplicity of mutually different models are provided. The respective model is then subjected to a goal achievement analysis and assigned to an optimization group or a committee group based on the results of the goal achievement analysis. From step S2, the method is then applied only to the models of the optimization group. In other words, before step S1, the optimization group, which has at least one model or more models, is created by selecting the best from the large number of models. The selection of the best then forms the basis for the next optimization group. This optimization group is formed by varying the selection of the best. As a result, the method is particularly efficient since the probability of achieving the desired target design of the component by means of the method increases. Furthermore, local minima are overcome in an optimization problem, which is also advantageous. Advantageously, the method is particularly unlikely to arrive at a component whose target design is inappropriate and/or undesirable.

It has also proven to be advantageous if, in order to ensure manufacturability, before the digital component model is provided, a movement trajectory of a production tool of the production unit to be traversed in order to produce the component is simulated. For example, it can be determined in this way whether, when the component is manufactured or produced, the production tool would have to perform movements that would not be possible due to the geometry of the production tool and/or the production unit. For example, a collision check can be carried out, in which it is examined whether the production tool would hit another object when following the movement trajectory. This object can be, for example, an element of the production tool or the production unit and/or a material component of the component. The object can also be formed by a support structure required for printing. In this respect, the method for producing the component is particularly efficient with regard to an overall process flow, since the method in this embodiment has a process simulation that provides information as to whether the component can actually be produced using the digital component model. Such a collision check or the checking of the movement trajectory can be carried out in particular after a matrix material and/or a fiber strand has been added to the model in a simulative manner.

The method described here can be used particularly efficiently and expediently in connection with a generative or additive manufacturing method, in particular 3D printing. This means that according to a further advantageous embodiment of the method, the component is produced using the digital component model using the generative or additive manufacturing process, for example 3D printing. Because by means of such a generative manufacturing process, components can be produced that have a particularly complex geometry, which is given, for example, by the material bridges.

If, in connection with the manufacturing process, it is determined that the support structure is necessary when the component is formed, provision is made for the support structure to be taken into account in the process simulation. The support structure is a support produced by the manufacturing unit or 3D printer from the same material used to manufacture the part. In other words, the support structure is also produced when the component is produced using the 3D printer, provided the support structure is required for the intended production of the component. A section/area of the component to be manufactured is supported against a work surface of the manufacturing unit by means of this support or by means of the support structure, in particular until the material has hardened and is itself capable of bearing loads. Such an area/section is supported by means of a respective support structure if a first layer of material and/or fiber strand layer is so far away from the work surface during printing that this layer (“layer”) would not retain its shape and position by itself.

The method benefits from an additive optimization procedure. A step-by-step production of material in a defined installation space, which is initially simulated in the form of the model, as well as material to be printed out or arranged according to the component model, is evaluated with regard to its manufacturability by a process simulation and subjected to a fitness evaluation with regard to its mechanical performance. In this way, the full potential of actual 3D printing, in contrast to regular 2.5D printing, can be used, for example using 5-axis printing machines.

Since many materials that can be processed or further processed using an additive manufacturing process show anisotropic material behavior, the presented optimization process can also be used to manufacture classic non-fiber-reinforced components. Here, for example, weak inter-layer connections in classic unreinforced additive polymer or metal printing can be taken into account.

In addition, it has proven to be advantageous if the respective fiber is spatially arranged by means of 3D fiber strand printing, the respective fiber and the respective matrix material sheath being coextruded with each other to form the respective fiber strand and at the same time being positioned according to the digital component model. This means that during 3D fiber strand printing, the matrix material and the respective fiber are fed to a print head of a 3D fiber strand printer at the same time, so that the 3D fiber strand printer prints the fiber strand from the (especially melted) matrix material and the fiber. This results in a particularly advantageous material composite between fiber strands printed one after the other, for example by the individual fiber strands with the matrix material jacket still at least partially melted being arranged directly adjacent to one another or directly touching one another, so that the fiber strands printed and arranged one after the other are bonded to one another while the matrix material jackets harden will. Once all the printed matrix material coats have hardened, a block of matrix material results, which is permeated by the fibers, so that the component is designed as the fiber-reinforced component.

Further features of the invention result from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations without departing from the scope of the invention .

• 1 zeigt ein Ablaufdiagramm zur Verdeutlichung eines Verfahrens zum Herstellen eines Bauteils;
• 2 zeigt eine schematische Ansicht eines digitalen Modells mit Lagerungspunkten und einer Materialkomponente;
• 3 zeigt eine schematische Ansicht des Modells, wobei ein spannungsarmer Anteil der Materialkomponente simulativ weggenommen wird;
• 4 zeigt eine schematische Ansicht des Modells, wobei ein Faserstrang simulativ hinzugefügt wird;
• 5 zeigt eine schematische Ansicht des Modells, wobei ein weiterer spannungsarmer Anteil der Materialkomponente simulativ weggenommen wird.

The invention will now be explained in more detail using preferred exemplary embodiments and with reference to the accompanying drawings.

• 1 shows a flowchart to clarify a method for producing a component;
• 2 shows a schematic view of a digital model with support points and a material component;
• 3 shows a schematic view of the model, wherein a low-stress part of the material component is removed in simulation;
• 4 Fig. 12 shows a schematic view of the model with a fiber strand being added as a simulation;
• 5 shows a schematic view of the model, with another low-stress Share of the material component is removed simulatively.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 FIG. 1 shows a flowchart that serves to clarify a method for producing a component 1. FIG. For easy understanding of this description should 1 in synopsis with the 2 , 3 , 4 and 5 are considered, in each of which the component 1 or a model 2 is shown in a schematic view, with the component 1 being produced on the basis of the model 2 in the method. The method has a large number of steps, which are described in more detail below. The order of description is not necessarily representative of the actual course of the procedure.

In a step S1 of the method, the digital model 2 is provided, the digital model 2 having two bearing points 3 spaced apart from one another. The bearing points 3 are formed in the digital model 2 as a load introduction point 4 or as a load discharge point 5, for example. Furthermore, in step S1 the digital model 2 is provided by the bearing points 3 , 4 , 5 being connected by means of a material component 6 . This means that to create the digital model 2, both the bearing points 3, 4, 5 and the material component 6 are simulated. Here, the material component 6 is simulated as an initially fiber-free matrix material 7 or as a fiber strand 8 .

The digital model 2 is made available to a step S2 of the method, in which a load 9 acting on the model 2 is simulated, which is conducted, for example, via the load introduction point 4 into the material component 6 and into the load discharge point 5 . In this case, mechanical stresses occur in the material component 6, that is to say in the matrix material 7 or in the driver train 8, which are detected by means of a stress analysis in step S2. The load 9 is, for example, a force that is simulated in the model 2 in such a way that the simulated force or load 9 corresponds to a real force or load that occurs when the component 1 is actually used, ie when it is manufactured or manufactured, is to be expected.

In a further step S3 of the method, an algorithm is applied to the model 2 based on the results of the stress analysis (see step S2). Model 2 represents input data that is processed using the algorithm. In this way, load paths between the bearing points 3, 4, 5 are determined or identified in the material component 6, that is to say in the matrix material 7 or in the fiber strand 8. These load paths are associated with parts of the material component 6 that are rich in stress. For example, the load paths run in the high-stress parts of the material component 6. This means, for example, that the load paths between the bearing points 3, 4, 5 are formed by the high-stress parts of the material component 6 as soon as the load 9 is simulated on the component 1 or on the digital model 2 is applied.

A removal of low-stress material parts 10 of the material component 6 is then simulated in a step S4. In other words, the model 2, which—at this stage of the process still roughly—represents the component 1 to be manufactured or a component model, is reduced by the low-stress material portions 10.

By the model 2 being reduced by the low-stress material portions 10, the digital component model is generated in a further step S5 of the method, which is provided to a production unit in a step S6. As a result, the component model emerges from the model 2 by the simulative removal of the low-stress material portions 10, so that the component 1 can be produced or produced using the component model by means of the production unit.

The production unit is designed in particular to produce the component based on the digital component model using an additive manufacturing process, for example 3D printing. For the process, this means that the component is produced generatively or additively by means of the production unit.

It is particularly preferred if a movement trajectory of a production tool of the production unit is simulated before the digital component model is provided, ie before step S6, for example in a step S5a provided after step S5. This means that the method has a process simulation, which can be used to determine or determine whether the component 1 can actually be manufactured without the production tool hitting another object when the production tool follows the movement trajectory for producing the component. This other object can be, for example, one of the material components 6 that has been added to the model 2, ie the digital component model, in the course of the method. Furthermore, the object can be an element of the production unit, for example a movable arm, for example a robot arm, a portal element, etc. It is provided in particular that the production tool is guided along the movement trajectory by means of the arm or robot arm and/or by means of the portal element in order to produce the component 1, for example to print it out or a support structure of the component to be printed. The component 1, which is produced and in particular optimized using the present method, may have a particularly complex geometry, so that this complex geometry must be checked for manufacturability and process reliability.

If the model 2 is simulated in the method in such a way that the material component 6 is simulated as the initially fiber-free matrix material 7 , in step S4 the simulative removal of the low-stress material portions 10 takes place by simulating low-stress portions of the matrix material 7 . If the model 2 is instead simulated in such a way that the material component 6 is simulated as the fiber strand 8 , the simulative removal of the low-stress material portions 10 takes place in step S4 by simulating low-stress portions of the fiber strand 8 being removed.

If a fiber strand is mentioned here, for example the fiber strand 8 and/or possibly further fiber strands, the respective fiber strand has at least one individual fiber and a matrix material jacket, the individual fiber or individual fibers being/are encased by the matrix material jacket. Consequently, in this case it is simulated in step S4 that low-stress portions of the individual fibers and/or the matrix material sheath are/is being removed.

After step S4, i.e. after the simulative removal of the low-stress material portions 10, for example in a step S4a, the material component 6 is supplemented by a further fiber strand 11 in such a way that the bearing points 3, 4, 5 are connected to one another by means of the further fiber strand 11 . This means that - if the model 2 is provided with the material component 6 designed as the initially fibre-free matrix material 7 - the initially fibre-free matrix material 7 is supplemented by the fiber strand 11, with the fiber strand 11 then being a first fiber strand of the model 2 or of the component 1 forms. On the other hand - if the model 2 is provided with the material component 6 designed as the fiber strand 8 - the fiber strand 11 forms an additional or further fiber strand 11 to the fiber strand 8. It is particularly preferred if, for example in step S4a, iteratively the further Fiber strand 11 is added and a removal of low-stress portions of this further fiber strand 11 is simulated. To this end, step S4 can include, for example, a further stress analysis, which is used to examine the further fiber strand 11 to determine the extent to which the further fiber strand 11 contributes to stability and/or to the achievement of a desired target design of the component 1 .

In 1 It can also be seen that an iteration SI is provided, the iteration SI comprising a step S4b and starting after step S4 has been run through for the first time. It can also be seen that the iteration SI ends before step S5, ie before the digital component model is generated. Here, in step S4b, a decision is made as to whether the iteration SI ends and step S5 follows, or whether a new iteration run is carried out. In the present example, the iteration SI includes at least the method steps S2, S3, S4 and S4b and optionally the step S4a. In order to decide in step S4b whether step S5b follows or a further iteration run, in step S4b the respective results of the stress analysis (see step S2) are compared with the results of the previous stress analysis and - if a predetermined or specifiable result improvement has not occurred - the step S5 initiated. However, if it is determined in step S4b that the result has improved, this means that the model 2 still has potential for optimization, so that a new iteration run is started, for example with step S2.

It is further provided in the present example that a set of boundary conditions R is assigned to the respective fiber strand, for example the fiber strand 8 and/or the fiber strand 11, in order to restrict a spatial arrangement when simulating the respective fiber strand 8, 11. This means that when simulating the respective fiber strand 8, 11 in the model 2 and consequently in the digital component model, the spatial arrangement of the respective fiber strand 8, 11 is based on the set of boundary conditions R. The set of boundary conditions R has one boundary condition or more boundary conditions, so that, for example, a first boundary condition of the set of boundary conditions R restricts the spatial arrangement of the respective fiber strand 8, 11 in such a way that it connects the bearing points 3, 4, 5 via a support point 12 or several support points 12 (see 2 ) connects to each other. This means that the set of boundary conditions R can have, for example, the boundary condition according to which the support point 12 or the support points 12 are simulated with the model 2, with the simulation of the corresponding material component 6 creating a connection between the material component 6 and the support points 12 or the Base 12 is simulated.

The set of boundary conditions R can have an additional boundary condition, so that an additional support point (not shown) is added to the model 2 . This further bearing point is designed in particular as a further load introduction point and/or a further load discharge point. As in the 2 until 5 can be seen, the matrix material 7 and/or the respective fiber strand 8, 11 can be connected to at least one of the support points 12, so that the matrix material 7 or the respective fiber strand 8, 11 has the bearing points 3, 4, 5 and any further bearing points connects the base 12 or via the bases 12 to one another.

If the model 2 is simulated in the method in such a way that the material component 6 is formed as the fiber strand 8, a further fiber strand (not shown) can be added to the model 2 as a reinforcing fiber strand, which in particular is parallel to the fiber strand 8 and/or parallel to the fiber strand 11 runs. It can further be provided that the reinforcing fiber strand is formed by adding the further fiber strand 11 . In other words, the further fiber strand 11 can represent the reinforcing fiber strand. If the model 2 is simulated in such a way that the material component 6 is formed as the initially fibre-free matrix material 7, it is provided that the reinforcing fiber strand is formed in addition to the fiber strand 11, in which case the fiber strand 11 is the first fiber strand for the initially fibre-free matrix material 7 is. The reinforcing fiber strand is preferably formed obliquely to the respective fiber strand 8, 11, so that a particularly high tensile strength ultimately results for the component 1 along the respective fiber strand 8, 11 and along the reinforcing fiber strand.

It is to be understood that the reinforcing fiber strand differs from the other fiber strands described herein, for example the fiber strands 8, 11, only with regard to its positional arrangement. This means that the reinforcing fiber strand is or will be designed in the same way as the other fiber strands described herein with regard to a material composition and in particular with regard to manufacturing. Consequently, the set of boundary conditions R can be assigned to the reinforced fiber strand, which means for the method that the reinforced fiber strand is simulated based on the set of boundary conditions R, in particular on one or more of the boundary conditions.

3D fiber strand printing is used in particular to produce the component 1, with the respective fiber strand being produced and spatially arranged in a single operation by means of the production unit, which is designed here as a 3D fiber strand printer. The production and the spatial arrangement of the respective fiber strand takes place based on the component model that is or was provided in step S6 of the method of the production unit, ie the 3D fiber strand printer. The 3D fiber strand printer produces the respective fiber strand, i.e. the fiber strand 8, the fiber strand 11, the reinforcing fiber strand and/or other fiber strands required for the component 1, in that the 3D fiber strand printer spatially arranges the respective individual fibers while the respective Individual fibers and an associated matrix material jacket, for example made of the matrix material 7, are coextruded together to form the respective fiber strand. During the production of the respective fiber strand, the matrix material 7 is initially in molten or pasty form, so that the molten or pasty matrix material 7 is fed to a print head of the 3D fiber strand printer, while the individual fibers, for example carbon fibers or carbon fibers, are fed to the print head will.

In particular, a multiplicity of models 2 that differ from one another are provided in, before or after step S1, for example in a step S1a. In this case, step S1 or S1a is followed by a further step S1b, in which the respective model 2 from the plurality of different models 2 is subjected to a goal achievement analysis and based on the results of this goal achievement analysis is assigned to an optimization group or a scrap group. If it is determined by means of the target achievement analysis for the respective model 2 that optimization using the method is worthwhile, this model is assigned to the optimization group. This means, for example, that the respective model 2 is examined by means of the target achievement analysis to determine whether a desired target design of the component 1 can be achieved by the method, in particular with a topology optimization inherent in the method.

For the further steps of the method it is then provided that only the models 2 from the optimization group are subjected to the method. In this respect, the method can be applied to the models 2 of the optimization group in succession. It is also possible for the models 2 of the optimization group to be subjected to the method described here in a temporally overlapping manner, in particular simultaneously. The method is described above using a model 2, this model 2 either coming from the optimization group or being the only model 2 for the method.

Overall, the examples show how a particularly efficient method for producing the in particular fiber-reinforced component 1 is carried out, the method having a topology optimization that can be carried out, for example, using a suitable computer program, such as an FEM program, in order to optimize the component model. This means that the component does not initially have to be physically produced in order to optimize it, so that the method takes particular account of the idea of an ecologically and economically particularly favorable production of the component 1 .

Reference List

1

component

2

model

3

storage points

4

load application point

5

load release point

6

material component

7

matrix material

8th

driver line

9

load

10

material proportions

11

fiber strand

12

base

R

boundary condition set

S1

process step

S1a

process step

S1b

process step

S2

process step

S3

process step

S4

process step

S4a

process step

S4b

process step

S5

process step

S5a

process step

S6

process step

S.I

iteration

Claims (15)

Method for producing a component (1), with the following steps: S1 providing a digital model (2) with two bearing points (3, 4, 5) spaced apart from one another, the bearing points (3, 4, 5) being connected by means of a material component (6, 7, 8, 11); S2 simulating a load (9) acting on the model (2) and carrying out a stress analysis of the material component (6, 7, 8, 11); S3 applying an algorithm based on the results of the stress analysis, as a result of which load paths between the bearing points (3, 4, 5) are determined in the material component (6, 7, 8, 11); S4 iterative simulation of removing low-stress material portions (10) of the material component (6, 7, 8, 11); S5 generation of a digital component model based on the model (2) reduced by the low-stress material portions (10); S6 delivery of the digital component model to a production unit in order to produce the component (1) using the digital component model. procedure after claim 1 , wherein in the model (2) the material component (6) is simulated as a fiber-free matrix material (7), so that in step S4 a removal of low-stress portions (10) of the matrix material (7) is simulated. procedure after claim 1 , wherein in the model (2) the material component (6) is simulated as a fiber strand (8, 11), the fiber strand (8, 11) having at least one fiber, the fiber having a matrix material sheath, so that in step S4 a removal is simulated by low-stress parts (10) of the fiber strand (8, 11). Method according to one of the preceding claims, wherein in the model (2) after step S4 in a step S4a the material component (6, 7, 8) is supplemented by a fiber strand (11) connecting the bearing points (3, 4, 5). Procedure according to claims 3 and 4 , wherein the material component (6) simulated as the fiber strand (8) in the model (2) is iteratively added to the further fiber strand (11) and a removal of low-stress portions (10) of the fiber strand (8, 11) is simulated. Method according to one of the preceding claims, wherein after step S4 has been run through for the first time, an iteration SI starting with step S2 and ending before step S5 is carried out, the iteration SI comprising a step S4b in which, after step S4, the respective results of the current stress analysis are Results of the previous stress analysis are compared, and - if a predetermined result improvement has not occurred - step S5 follows step S4b. Procedure according to one of claims 3 until 6 , wherein a set of boundary conditions (R) is assigned to the respective fiber strand (8, 11), whereby a spatial arrangement of the respective fiber strand (8, 11) is based on the set of boundary conditions (R) when simulating the respective fiber strand (8, 11). procedure after claim 7 , wherein in the model (2) a boundary condition of the boundary condition set (R) defines a support point (12) between the bearing points (3, 4, 5), wherein the support point (12) when simulating the respective fiber strand (8, 11) is connected to the fiber strand (8, 11). procedure after claim 7 or 8th , wherein in the model (2) a further boundary condition of the boundary condition set (R) defines a further bearing point that is different from the two bearing points (3, 4, 5), the further bearing point when simulating the respective fiber strand (8, 11) with the fiber strand (8, 11) is connected. Procedure according to one of claims 3 until 9 wherein at least one reinforcing fiber strand is simulated in the model, the reinforcing fiber strand and the respective fiber strand (8, 11) being arranged at an angle to one another. procedure after claim 10 and one of the Claims 7 until 9 , wherein in the model (2) the fiber strand (8, 11) to which the boundary condition data set is assigned is simulated as the reinforcing fiber strand. Method according to one of the preceding claims, wherein a large number of mutually different models (2) is provided, after which the respective model (2) is subjected to a goal achievement analysis and based on the results of the goal achievement analysis an optimization group or a committee group is assigned, and the steps of the method from step S2 can only be applied to the models (2) of the optimization group. Method according to one of the preceding claims, wherein to ensure manufacturability before the digital component model is provided, a movement trajectory of a production tool of the production unit to be traversed to produce the component (1) is simulated. Method according to one of the preceding claims, in which the component (1) is produced on the basis of the digital component model by means of an additive manufacturing process. Procedure according to one of claims 3 until 14 , wherein the respective fiber is spatially arranged by means of 3D fiber strand printing, the respective fiber and the respective matrix material sheath being coextruded with one another to form the respective fiber strand (8, 11).

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