CN107035203A - A kind of SMA energy consumers prestressing without bondn system - Google Patents

Abstract

The present invention discloses a kind of SMA energy consumers prestressing without bondn system, is made up of prestressing without bondn part and SMA energy consumers；Prestressing without bondn part is made up of presstressed reinforcing steel and anchorage connection；SMA energy consumers include SMA element, connector, rigid sleeve and SMA heaters；SMA element two ends are connected with connector, and SMA element and connector are collectively disposed inside rigid sleeve；Presstressed reinforcing steel is connected by connector with SMA element；The end cover of SMA element is connected provided with heater, and heater passes through external wire electrified regulation SMA element.Using SMA SME, it can be achieved to structure or the active control of component, can more effectively realize the Damage Coutrol of the reparation to structural damage and the residual deformation to structure, make up the loss of prestress caused by other accidentalia in runback bit architecture.

Description

A SMA Energy Dissipator-Unbonded Prestressing System

technical field

The invention relates to an SMA energy dissipator-non-adhesive prestressing system, which can be used for a self-resetting structure or a prestressing structure with special requirements.

Background technique

SMA (Shape Memory Alloy, referred to as SMA) is a metal material with both sensing and driving functions. It has shape memory effect, superelastic effect, damping effect, resistance characteristics, high strength, good plasticity, corrosion resistance, and fatigue life. Long and other excellent characteristics. At present, various forms of SMA energy dissipators, rods, reinforcements, etc. have been applied in civil engineering structures.

The self-resetting structure means that under the action of an earthquake, the structure first undergoes a certain bending deformation, and after exceeding a certain limit, it sways, and the structure returns to its original position through prestressing. Currently, self-resetting structures include self-resetting bridge piers, self-resetting reinforced concrete frames, self-resetting steel frames, and self-resetting shear walls. However, the existing research on self-resetting structures shows that although the rocking structure using the prestressed system can effectively alleviate the earthquake damage of the structure under the action of earthquake force, compared with the traditional structure, the energy dissipation capacity of the self-resetting structure is insufficient. Setting some external energy consumers can improve the energy consumption to a certain extent, but how to improve its energy dissipation capacity more effectively is still the key to the further development of the self-resetting structure.

Contents of the invention

The present invention proposes an unbonded prestressing system using SMA energy dissipators. The SMA energy dissipators are combined with unbonded prestressed parts, and the SMA energy dissipators are induced to produce nonlinear elastic deformation by changes in the internal force of the prestressed tendons. The structure or component provides energy dissipation; the SMA shape memory effect is used to drive the prestressed tendon system to realize active control of the structure or component.

The specific implementation mode that the present invention adopts is:

An SMA energy dissipator-unbonded prestressed system is composed of an unbonded prestressed part and an SMA energy dissipator.

The unbonded prestressed part is one of unbonded prestressed steel bars, steel strands or FRP bars and corresponding anchors.

The SMA energy dissipator 2 includes SMA components, connectors, rigid sleeves and SMA heating devices; both ends of the SMA components are connected to the connectors, and the SMA components and the connectors are placed inside the rigid sleeve; the prestressed tendons are connected to the rigid sleeve through the connectors The SMA elements are connected; both ends of the SMA element are connected to a heating device, and the heating device is heated through an external reserved wire.

The advantages of the present invention are:

1. Connecting the SMA energy dissipator in series with the prestressed tendon system can make the SMA in a pre-tensioned state. At the same time, the deformation of the prestressed tendons can be used to induce the nonlinear elastic deformation of the SMA. The SMA has higher energy consumption efficiency and can improve the structure more effectively. energy consumption capacity.

2. The energy dissipator can be used as a driver at the same time. Using the shape memory effect of SMA, it can realize the active control of the structure or components, and can more effectively realize the repair of structural damage and the damage control of the residual deformation of the structure. Loss of prestress caused by other accidental factors in the reset structure.

3. The prestressed structure will inevitably produce prestress loss during use. During normal use, the SMA shape memory effect can compensate for the prestress loss of components and ensure the functionality of the structure.

4. The shape memory effect of SMA can be used to realize the active repair of damaged structures or components after earthquakes.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

FIG. 2 is a schematic diagram of the self-resetting frame of Embodiment 1. FIG.

Fig. 3 is a schematic diagram of the self-resetting pier of Embodiment 2.

detailed description

In order to further illustrate the working mechanism of the present invention and highlight its functionality, the present invention will be further described in detail with reference to the accompanying drawings.

As shown in Figure 1, a SMA energy dissipator-unbonded prestressing system consists of an unbonded prestressed part 1 and an SMA energy dissipator 2.

The unbonded prestressed part adopts one of unbonded prestressed steel bars, steel strands or FRP bars and corresponding anchors 1-2.

The SMA energy dissipator 2 includes an SMA element 2-1, a connector 2-2, a rigid sleeve 2-3 and an SMA heating device 2-4; both ends of the SMA element are connected to the connector, and the SMA element and the connector are placed together Inside the rigid sleeve 2-3; the prestressed rib 1-1 is connected to the SMA element 2-1 through the connector 2-2; the two ends of the SMA element are connected to the heating device 2-4, and the heating device 2-4 is connected to the external reserved wire Electric heating.

SMA element 2-1 adopts one of SMA wire, rod or reinforcement, and the ultimate load is less than the yield load of the prestressed tendon. In the ultimate state, the SMA element first produces a large nonlinear elastic deformation.

The prestressed tendon 1-1 and the SMA energy dissipator form a series system through the connector, and the SMA element is in a pre-tensioned state after the pre-stress is applied by the post-tensioning method.

SMA components adopt SMA wire, rod or rib.

The structural form of the connector is determined according to the structural form and quantity of the prestressed tendons and SMA elements. The connector can be used with the existing screw-end rod anchor, pier head anchor, tapered anchor, and clip anchor; the connector can meet the strength , stiffness and deformation requirements.

There is a stroke space inside the sleeve, which allows the SMA element to produce a predetermined amount of deformation.

The heating device 2-4 adopts various heating mechanisms to realize the temperature rise of the SMA element, specifically, a DC power supply is directly energized for heating or a resistance wire arranged on the surface of the SMA is energized for heating.

SMA electric heating device 2-4 is arranged on the outside of the sleeve, the inside is connected to the SMA, and the outside is connected to the surface of the component. When the component is actively controlled, the external DC power supply can be directly connected to heat the SMA element, triggering its shape memory effect.

The location and number of SMA energy dissipators 2 in the component can be determined according to the design and use requirements. Try to arrange them at the preset damage position of the component, such as the plastic hinge of the beam and column, so as to give full play to its energy consumption and active control of the component. effect.

The scope of protection of the present invention includes but is not limited to the products and styles of the above-mentioned specific embodiments, any SMA-prestressed tendon system that conforms to the claims of the present invention and any appropriate changes or modifications made by those skilled in the art are all Should fall within the scope of protection of this patent.

Example

As shown in Figure 2, for a concrete self-resetting frame, unbonded prestressed tendons are installed in the beam, and the SMA energy dissipator is installed in the prestressed tendon system at the plastic hinge of the beam. First, non-linear elastic deformation is generated, which can cause the beam at the corresponding part to form a plastic hinge. Under the action of reciprocating load, the energy dissipator at the plastic hinge can provide the frame with maximum energy consumption. After the earthquake, it is heated through the interface reserved outside the beam. Energy dissipator to realize the active repair of the frame structure.

As shown in Figure 3, a concrete self-resetting segment assembled bridge pier is connected to each segment of the column body by post-tensioning unbonded prestressed tendons, and the SMA energy dissipation is set in the prestressed tendon system in the potential plastic hinge area of the upper and lower roots Under the action of the earthquake, the segmental deformation in this area is the most serious, and the energy dissipation efficiency of the internal energy dissipator in this segment is higher than that in other positions. After the earthquake, the prestressed system can generate restoring force by heating the SMA with electricity. Further reduce the residual deformation of the cylinder.

Claims (8)

1. a kind of SMA energy consumers-prestressing without bondn system, it is characterised in that：By prestressing without bondn part and SMA energy consumers Composition.

2. SMA energy consumers-prestressing without bondn system as claimed in claim 1, it is characterised in that：Prestressing without bondn part It is using one kind in no-cohesive prestressed reinforcement, steel strand wires or FRP muscle and corresponding anchorage.

3. SMA energy consumers-prestressing without bondn system as claimed in claim 1, it is characterised in that：SMA energy consumers 2 include SMA element, connector, rigid sleeve and SMA heaters；SMA element two ends are connected with connector, by SMA element and connection Device is collectively disposed inside rigid sleeve；Presstressed reinforcing steel is connected by connector with SMA element；SMA element two ends connection heating dress Put, heater passes through external reserved wire electrified regulation.

4. SMA energy consumers-prestressing without bondn system as claimed in claim 3, it is characterised in that：

SMA element uses a kind of in SMA silk materials, bar or muscle material, and ultimate load is less than presstressed reinforcing steel yield load, in limit shape Under state, SMA element produces larger nonlinear elastic deformation first；

Both presstressed reinforcing steel and SMA energy consumers are applied after prestressing force at SMA element by connector formation serial system, post stretching In pre- tension state.

5. SMA energy consumers-prestressing without bondn system as claimed in claim 3, it is characterised in that：SMA element uses SMA Material, bar or muscle material.

6. SMA energy consumers-prestressing without bondn system as claimed in claim 3, it is characterised in that：Connect utensil tectosome shape Formula determines that connector can coordinate existing screw side pole anchor, pier nose according to presstressed reinforcing steel and SMA element structural form and quantity Anchor, anchoring cone, the anchorage of intermediate plate anchor are used；Connector can meet the requirement in terms of intensity, rigidity and deformation.

7. SMA energy consumers-prestressing without bondn system as claimed in claim 3, it is characterised in that：Sleeve inner has stroke Space, it is allowed to which SMA element produces predetermined deflection.

8. SMA energy consumers-prestressing without bondn system as claimed in claim 3, it is characterised in that：Heater is using a variety of Heating mechanism realizes the heating to SMA element, specifically arranges electricity using the heating of dc source direct-electrifying or using SMA surface Hinder silk electrified regulation.