Self-resetting assembly type buckling-restrained brace with built-in SMA pull rods

Abstract

The self-resetting assembly type buckling-restrained brace comprises an inner cylinder, a left plate is arranged at the left end of the inner cylinder, a pushing rod is arranged in the right end of the inner cylinder in a stringing mode, the other end of the pushing rod is sleeved with a right plate, a pushing plate is further arranged on the side, away from the pushing rod, of the right plate, and four SMA pull rods penetrating from the left end to the right end of the inner cylinder are further arranged on the inner cylinder; a right end plate is further fixed to the right side of the push plate, a cushion plate and a left end plate are further sequentially arranged at the left end of the inner cylinder, inner cores are further symmetrically placed on the front side face and the rear side face of the inner cylinder, the right ends of the inner cores are fixed to the right end plate, and the left ends of the inner cores penetrate through the cushion plate to be fixed to the left end plate. The buckling-restrained brace solves the problem that in the prior art, a buckling-restrained brace is prone to generating large residual deformation after an earthquake, and consequently the structure and components cannot continue to play a role.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering shock-absorbing structures and relates to a self-resetting assembled anti-buckling support with a built-in SMA pull rod. Background Art

[0002] Earthquakes, as a major natural disaster, seriously affect human life and safety. Traditional building structures are prone to damage under earthquakes, which results in the structure not meeting the requirements of safety and stability, causing inestimable economic losses and casualties. Buckling-resistance braces, as an energy dissipation and shock reduction measure, can effectively absorb energy under earthquakes and minimize structural damage. However, buckling-resistance braces are prone to produce large residual deformations after earthquakes, which results in the inability of structures and components to continue to function and makes repairs more difficult, resulting in inestimable losses. Therefore, how to effectively reduce the residual deformation of the structure is an important factor that cannot be ignored in earthquake-resistant design. Summary of the invention

[0003] The purpose of the present invention is to provide a self-resetting assembled anti-buckling support with a built-in SMA pull rod, which solves the problem in the prior art that the anti-buckling support is prone to produce large residual deformation after an earthquake, resulting in the inability of the structure and components to continue to function.

[0004] The technical solution adopted by the present invention is a self-resetting assembled anti-buckling support with a built-in SMA pull rod, comprising an inner cylinder, a left plate is arranged at the left end of the inner cylinder, a push rod is arranged in series inside the right end of the inner cylinder, a right plate is sleeved on the other end of the push rod, a push plate is also arranged on the side of the right plate away from the push rod, and four SMA pull rods are also arranged on the inner cylinder passing through the left end to the right end of the inner cylinder, both ends of the SMA pull rod pass through the left and right ends of the inner cylinder and are fixed on the left plate or the right plate on the corresponding side, a right end plate is also fixed on the right side of the push plate, a pad plate and a left end plate are also arranged in sequence at the left end of the inner cylinder, and an inner core is symmetrically placed on the front and rear side surfaces of the inner cylinder, the right end of the inner core is fixed on the right end plate, and the left end of the inner core passes through the pad plate and is fixed on the left end plate.

[0005] An upper sleeve and a lower sleeve are respectively arranged on the upper and lower parts of the inner cylinder. One end of the upper sleeve and the lower sleeve close to the pad is fixed on the pad. The front and rear sides of the upper sleeve and the lower sleeve are respectively fixedly connected by a front cover plate and a rear cover plate.

[0006] The inner cylinder is a rectangular shell-like structure, and the inner cylinder is provided with middle holes at the left and right ends along its length direction. A fixing rod is provided in the middle of the left plate close to the inner cylinder, perpendicular to the left plate and integrally, and the fixing rod extends into the middle hole at the left end of the inner cylinder. One end of the push rod extends into the middle hole at the right end of the inner cylinder and is pressed against the fixing rod. A fixing cylinder is provided in the middle of the right plate close to the inner cylinder, perpendicular to the right plate and integrally, and the other end of the push rod is fixed to the fixing cylinder by a threaded connection. A threaded hole is provided in the center of the right plate close to the push plate, and the positions of the push plate close to the right plate correspond to the positions of the threaded holes in sequence A threaded rod is provided at the position, and the threaded rod extends into the threaded hole to fix the push plate and the right plate. After installation, the left plate fits with the left end surface of the inner cylinder, and the right plate fits with the right end surface of the inner cylinder. The longitudinal sections of the right plate and the left plate are adapted to the longitudinal section of the inner cylinder cuboid. Four SMA pull rods are evenly distributed at the four corners of the rectangular longitudinal section of the inner cylinder, and pass through the left plate, the inner cylinder, and the right plate from left to right in turn, and then extend out of the left plate and the right plate to fix nuts at both ends; extension plates that are integral with the inner cylinder are extended from the front and rear sides of the inner cylinder toward the left and right ends of the inner cylinder, and the pad is fixed to the two extension plates at the left end of the inner cylinder.

[0007] A fixing plate is provided at the position of the two extension plates on one side of the pad close to the inner tube, and the corresponding inner walls of the two fixing plates are respectively fitted with the outer sides of the extension plates on the corresponding side. The pad and the inner tube are fixed by bolts to the corresponding fixing plates and extension plates. Grooves adapted to the shape of the inner core are provided at the positions of the inner cores on the front and rear sides in the pad, and the left ends of the inner cores on the front and rear sides are respectively fixed to the front and rear sides of the left end plate after passing through the grooves.

[0008] The inner core includes a core plate with a rectangular cross section, and core heads are integrally arranged and connected to the core plate at both ends of the core plate along the length direction. The core head includes a transition plate integrally arranged with the core plate and connected to the two ends of the core plate along the length direction. The cross section of the transition plate is an isosceles trapezoid. The upper side of the isosceles trapezoid of the transition plate is the same as the width of the core plate and is integrally connected to both ends of the core plate. One side of the lower side of the isosceles trapezoid of the transition plate is connected to a reinforcing fixing plate with a rectangular cross section. The width of the reinforcing fixing plate is the same as the width of the lower side of the isosceles trapezoid of the transition plate. The reinforcing fixing plate is integrally arranged with the transition plate. The core plate, the transition plate, and the reinforcing fixing plate are located on the same plane. A reinforcing rib plate perpendicular to the transition plate is also commonly arranged on the same side of the transition plate and the reinforcing fixing plate. The reinforcing rib plate is integrally arranged with the transition plate and the reinforcing fixing plate, and is located on the extension line of the center line of the core plate. The core heads at the left ends of the inner core on the front and rear sides are respectively fixed to the front and rear sides of the left end plate after passing through the groove, and the core heads at the right ends of the inner core on the front and rear sides are fixed to the front and rear sides of the right end plate.

[0009] The upper sleeve and the lower sleeve are both configured as "concave" shell-like structures, and the "concave" shapes of the upper sleeve and the lower sleeve are buckled together to form a rectangular cylindrical structure. A plurality of fixing holes are evenly arranged on the "concave" side walls of the upper sleeve and the lower sleeve, and fixing holes a are also opened on the front cover plate and the rear cover plate at positions corresponding to the fixing holes of the upper sleeve and the lower sleeve. After the upper sleeve and the lower sleeve are buckled together, the front cover plate and the rear cover plate are correspondingly placed on the front and rear sides after the upper sleeve and the lower sleeve are buckled together, and are fixed by bolts passing through the corresponding fixing holes and fixing holes a. Fixing plates a are also provided on the front and rear sides of the upper sleeve and the lower sleeve at the positions corresponding to the pads. The fixing plate a of the upper sleeve extends downward to the upper ends of the front and rear sides of the pad, and the fixing plate a of the lower sleeve extends upward to the lower ends of the front and rear sides of the pad, and the upper sleeve and the lower sleeve are fixed to the pad by bolts fixing the pad and the fixing plate a.

[0010] The left end plate and the pad are fixed by bolts, the right end plate and the push plate are fixed by bolts, the core heads at the left ends of the inner cores on the front and rear sides pass through the grooves, and the reinforcing fixing plates at the right ends of the inner cores on the front and rear sides are fixed by bolts to the front and rear sides of the right end plate.

[0011] The formula for calculating the cross-sectional area of ​​the SMA rod in the direction perpendicular to the long axis is as follows:

[0012]

[0013] Among them, α sc It represents the ratio of the prestress of the SMA rod to the yield strength of the inner core after strengthening, α sc ≥1, β represents the adjustment factor of the compressive strength of the inner core; ω represents the adjustment factor of the strain hardening of the inner core, F y 、F m They represent the yield stress of the inner core and the prestress applied by the SMA rod, respectively;

[0014] A y It represents the longitudinal cross-sectional area of ​​the core board in the inner core, and its calculation formula is as follows:

[0015]

[0016] Among them, P u The actual axial bearing capacity of the self-resetting assembled buckling-restrained brace with built-in SMA rods satisfies the following formula:

[0017] φP n ≥P u

[0018] Among them, P n is the axial design bearing capacity of the self-resetting assembled buckling-restrained brace with built-in SMA rod, and φ represents the strength reduction factor.

[0019] The beneficial effects of the present invention are:

[0020] The present invention introduces the design of an SMA tie rod. SMA, or shape memory alloy, has the characteristic of automatically generating restoring stress and strain. By utilizing the material characteristics of the SMA tie rod, the automatic resetting function of the support after being subjected to force is realized. The self-resetting system of the present invention effectively overcomes the defect that traditional anti-buckling supports will produce large residual deformation after suffering an earthquake. It not only retains the good energy dissipation capacity of the anti-buckling support, but also significantly reduces the residual deformation of the support, thereby achieving a perfect combination of energy dissipation and reduction of residual deformation.

[0021] Compared with ordinary supports, the support structure of the present invention has clear structural force, reliable force transmission, and the characteristic of replaceable segments after being damaged by strong earthquakes. It has the advantages of light weight, easy installation, convenient inner core replacement, and reuse of restraining components, and has good economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an assembly diagram of the self-resetting assembled buckling-restrained brace with built-in SMA pull rod of the present invention;

[0023] Figure 2 It is an exploded view of the self-resetting assembled buckling-restrained brace with built-in SMA tie rod of the present invention;

[0024] Figure 3 It is an assembly diagram of the self-resetting system in the self-resetting assembled buckling-restrained brace with built-in SMA pull rod of the present invention;

[0025] Figure 4 It is an exploded view of the self-resetting system in the self-resetting assembled buckling-restrained brace with built-in SMA pull rod of the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the inner cylinder in the self-resetting assembled buckling-restrained support with built-in SMA pull rod of the present invention;

[0027] Figure 6 It is a structural schematic diagram of the right plate in the self-resetting assembled buckling-restrained brace with built-in SMA pull rod of the present invention;

[0028] Figure 7 It is an exploded view of the buckling restraining system in the self-resetting assembled buckling restraining brace with built-in SMA tie rod of the present invention;

[0029] Figure 8 It is a structural schematic diagram of a pad in a self-resetting assembled buckling-restrained support with a built-in SMA pull rod of the present invention;

[0030] Fig. 9 It is a schematic structural diagram of the inner core of the self-resetting assembled buckling-resistance brace with built-in SMA pull rod of the present invention.

[0031] Fig.10 It is a schematic diagram of the working principle of the self-resetting assembled buckling-resistance brace with built-in SMA pull rod of the present invention.

[0032] Fig.11 It is a comparison result diagram of the hysteresis curves of the self-resetting assembled buckling-resistance brace with built-in SMA pull rod and the assembled buckling-resistance brace of the present invention.

[0033] In the figure: 2-1. Inner cylinder, 2-1-1. Middle hole, 2-1-2. Extension plate, 2-2. Left plate, 2-2-1. Fixed rod, 2-3. Right plate, 2-3-1. Fixed cylinder, 2-3-2. Threaded hole, 2-4. Push rod, 2-5. SMA pull rod, 2-6. Push plate, 2-6-1. Threaded rod, 3-1. Front cover plate, 3-1-2. Concave notch, 3-2. Rear cover plate, 3-3. Left end plate, 3-4. Right end plate, 3-5. Upper sleeve, 3-5-1. Fixed plate a, 3-6. Lower sleeve, 3-7. Pad, 3-8. Inner core, 3-8-1. Core plate, 3-8-2. Transition plate, 3-8-3. Reinforced fixed plate, 3-8-4. Reinforced rib plate, 3-9. Fixed hole, 3-10. Fixed hole a. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] The self-resetting assembled anti-buckling support with built-in SMA pull rod of the present invention has a structure as follows Figure 1-2 As shown, it includes an inner cylinder 2-1, a left plate 2-2 is arranged at the left end of the inner cylinder 2-1, a push rod 2-4 is arranged in series inside the right end of the inner cylinder 2-1, a right plate 2-3 is sleeved at the other end of the push rod 2-4, and a push plate 2-6 is also arranged on the side of the right plate 2-3 away from the push rod 2-4, as shown in FIG. Figure 3-4 As shown, the inner cylinder 2-1 is also provided with four SMA pull rods 2-5 that pass through the left end to the right end of the inner cylinder 2-1. The two ends of the SMA pull rods 2-5 pass through the left and right ends of the inner cylinder 2-1 and are fixed on the left plate 2-2 or the right plate 2-3 on the corresponding side. A right end plate 3-4 is also fixed to the right side of the push plate 2-6. A pad plate 3-7 and a left end plate 3-3 are also sequentially provided on the left end of the inner cylinder 2-1. Inner cores 3-8 are also symmetrically placed on the front and rear side surfaces of the inner cylinder 2-1. The right end of the inner core 3-8 is fixed on the right end plate 3-4, and the left end of the inner core 3-8 passes through the pad plate 3-7 and is fixed on the left end plate 3-3.

[0037] An upper sleeve 3-5 and a lower sleeve 3-6 are respectively provided above and below the inner cylinder 2-1. One end of the upper sleeve 3-5 and the lower sleeve 3-6 close to the pad 3-7 is fixed on the pad 3-7. The front and rear sides of the upper sleeve 3-5 and the lower sleeve 3-6 are respectively fixedly connected by the front cover 3-1 and the rear cover 3-2.

[0038] like Figure 4-5 As shown, the inner cylinder 2-1 is a rectangular shell-like structure, and the inner cylinder 2-1 is provided with middle holes 2-1-1 at the left and right ends along the length direction thereof, and a fixing rod 2-2-1 is provided in the middle of one side of the left plate 2-2 close to the inner cylinder 2-1, perpendicular to the left plate 2-2 and integrally therewith, and the fixing rod 2-2-1 extends into the middle hole 2-1-1 at the left end of the inner cylinder 2-1, and one end of the push rod 2-4 extends into the middle hole 2-1-1 at the right end of the inner cylinder 2-1 and is pressed against the fixing rod 2-2-1, and a fixing cylinder 2-3-1 is provided in the middle of one side of the right plate 2-3 close to the inner cylinder 2-1, perpendicular to the right plate 2-3 and integrally therewith, as shown in FIG. Figure 6 As shown, the other end of the push rod 2-4 is fixed to the fixed cylinder 2-3-1 by threaded connection, a threaded hole 2-3-2 is set at the center of one side of the right plate 2-3 close to the push plate 2-6, and a threaded rod 2-6-1 is set at the position of the push plate 2-6 close to the right plate 2-3 corresponding to the threaded hole 2-3-2, and the threaded rod 2-6-1 extends into the threaded hole 2-3-2 to fix the push plate 2-6 and the right plate 2-3. After installation, the left plate 2-2 and the left end surface of the inner cylinder 2-1 are in contact, the right plate 2-3 and the right end surface of the inner cylinder 2-1 are in contact, and the right plate 2-3 and the left plate 2 -2 is adapted to the longitudinal section of the inner tube 2-1 rectangular parallelepiped, and four SMA tie rods 2-5 are evenly distributed at the four corners of the inner tube 2-1 longitudinal section rectangle. From left to right, they pass through the left plate 2-2, the inner tube 2-1, and the right plate 2-3 in sequence, and then the SMA tie rods 2-5 extend out of the left plate 2-2 and the right plate 2-3 to fix nuts at both ends; the front and rear side surfaces of the inner tube 2-1 are extended toward the left and right ends of the inner tube 2-1 to form an extension plate 2-1-2 that is integrally arranged with the inner tube 2-1, and the pad 3-7 is fixed on the two extension plates 2-1-2 at the left end of the inner tube 2-1.

[0039] like Figure 7-9 As shown, a fixing plate 3-7-1 is provided at the position of the two extension plates 2-1-2 on one side of the pad 3-7 close to the inner tube 2-1, and the corresponding inner side walls of the two fixing plates 3-7-1 are respectively fitted with the outer sides of the extension plates 2-1-2 on the corresponding side. The pad 3-7 and the inner tube 2-1 are fixed by bolts to the corresponding fixing plates 3-7-1 and extension plates 2-1-2. A groove 3-7-2 adapted to the shape of the inner core 3-8 is provided in the pad 3-7 at the position corresponding to the inner core 3-8 on the front and rear sides, and the left ends of the inner core 3-8 on the front and rear sides are respectively fixed to the front and rear sides of the left end plate 3-3 after passing through the groove 3-7-2.

[0040] The inner core 3-8 includes a core board 3-8-1 with a rectangular cross section, and the core board 3-8-1 is integrally provided with a core head at both ends of the core board 3-8-1 along its length direction. The core head includes a transition board 3-8-2 integrally provided with the core board 3-8-1 and connected to the core board 3-8-1 at both ends of the core board 3-8-1 along its length direction. The cross section of the transition board 3-8-2 is an isosceles trapezoid. The upper side of the isosceles trapezoid of the transition board 3-8-2 is the same as the width of the core board 3-8-1 and is integrally provided with the two ends of the core board 3-8-1. A reinforcing fixing board 3-8-3 with a rectangular cross section is connected to one side of the lower side of the isosceles trapezoid of the transition board 3-8-2. The width of the reinforcing fixing board 3-8-3 is the same as the width of the lower side of the isosceles trapezoid of the transition board 3-8-2. Similarly, the reinforcing fixing plate 3-8-3 is integrated with the transition plate 3-8-2, the core plate 3-8-1, the transition plate 3-8-2 and the reinforcing fixing plate 3-8-3 are located on the same plane, and a reinforcing rib plate 3-8-4 perpendicular to the transition plate 3-8-2 is also commonly provided on the same side of the transition plate 3-8-2 and the reinforcing fixing plate 3-8-3, the reinforcing rib plate 3-8-4 is integrated with the transition plate 3-8-2 and the reinforcing fixing plate 3-8-3, and is located on the extension line of the center line of the core plate 3-8-1, the core heads at the left ends of the inner cores 3-8 on the front and rear sides pass through the grooves 3-7-2 and are fixed to the front and rear sides of the left end plate 3-3 respectively, and the core heads at the right ends of the inner cores 3-8 on the front and rear sides are fixed to the front and rear sides of the right end plate 3-4.

[0041] The upper sleeve 3-5 and the lower sleeve 3-6 are both configured as "concave" shell-like structures. The "concave" shapes of the upper sleeve 3-5 and the lower sleeve 3-6 are buckled together to form a rectangular cylindrical structure. A plurality of fixing holes 3-9 are evenly arranged on the "concave" side walls of the upper sleeve 3-5 and the lower sleeve 3-6. Fixing holes a3-10 are also provided on the front cover plate 3-1 and the rear cover plate 3-2 at positions corresponding to the fixing holes 3-9 of the upper sleeve 3-5 and the lower sleeve 3-6. After the upper sleeve 3-5 and the lower sleeve 3-6 are buckled together, the front cover plate 3-1 and the rear cover plate 3-2 are placed on the upper sleeve 3-5 and the lower sleeve 3-6 respectively. The front and rear sides after being buckled are fixed by bolts passing through the corresponding fixing holes a3-9 and fixing holes a3-10. The front and rear sides of the upper sleeve 3-5 and the lower sleeve 3-6 corresponding to the position of the pad 3-7 are also provided with fixing plates a3-5-1. The fixing plate a3-5-1 of the upper sleeve 3-5 extends downward to the upper ends of the front and rear sides of the pad 3-7, and the fixing plate a3-5-1 of the lower sleeve 3-6 extends upward to the lower ends of the front and rear sides of the pad 3-7. The upper sleeve 3-5 and the lower sleeve 3-6 are fixed to the pad 3-7 and the fixing plate a3-5-1 by bolts.

[0042] The left end plate 3-3 and the pad 3-7 are fixed by bolts, the right end plate 3-4 and the push plate 2-6 are fixed by bolts, the core heads at the left ends of the inner cores 3-8 on the front and rear sides pass through the grooves 3-7-2, and the reinforcing fixing plates 3-8-3 are fixed to the front and rear sides of the left end plate 3-3 by bolts, and the reinforcing fixing plates 3-8-3 at the right ends of the inner cores 3-8 on the front and rear sides are fixed to the front and rear sides of the right end plate 3-4 by bolts.

[0043] In the present invention, the inner cylinder 2-1, the left plate 2-2, the right plate 2-3, the push rod 2-4, the SMA pull rod

[0044] 2-5 and the push plate 2-6 form a self-resetting system; the front cover plate 3-1, the rear cover plate 3-2, the left end plate 3-3, the right end plate 3-4, the upper sleeve 3-5, the lower sleeve 3-6, the pad 3-7 and the inner core 3-8 constitute an anti-buckling system.

[0045] The working principle of this embodiment is:

[0046] For the self-reset system, first, the right plate 2-3 is put inside the push rod 2-4, and then the push rod 2-4 and the right plate 2-3 are inserted from the right into the middle hole 2-1-1 of the inner tube 2-1, and then the left plate 2-2 is inserted from the left into the middle hole 2-1-1 of the inner tube 2-1, and then the SMA rod 2-5 is inserted into the four box mounting holes reserved on the left plate 2-2, the inner tube 2-1, and the right plate 2-3 in turn, and finally the corresponding prestress is applied to the SMA rod 2-5 and fixed by bolts to form a self-reset system;

[0047] For the anti-buckling system, firstly, the pad 3-7 and the left end plate 3-3 are connected by bolts, and then the double inner core 3-8 is respectively passed through the groove 3-7-2 where the pad 3-7 is located, and the left side of the inner core 3-8 is connected with the left end plate 3-3 by bolts, and then the self-resetting system is assembled, the inner tube 2-1 and the pad 3-7 are spliced ​​and connected by bolts, and the right side of the inner core 3-8 is connected with the right end plate 3-4 by bolts, and then the upper sleeve 3-5 and the lower sleeve 3-6 are respectively placed on the upper and lower sides of the pad and connected by bolts, and finally the front cover plate 3-1 and the rear cover plate 3-2 are respectively covered on the front and rear sides of the double inner core and are in close contact with the upper and lower sleeves, and fixed by bolts to complete the assembly of the self-resetting assembled anti-buckling support with built-in SMA pull rod.

[0048] During the stress process, the assembled buckling-resistance brace with built-in SMA tie rods uses the left end plate 3-3 as the fixed end and the right end plate 3-4 as the load end. The overall displacement of the support is applied to the right end plate 3-4, so that the push rod 2-4 drives the buckling-resistance system and the self-reset system to work together under the action of tension and compression. During the stress process, tension is positive and compression is negative. The support mainly goes through the following stages during the tension process:

[0049] (1) Initial stage, the initial state is as follows Fig.10 As shown, no external force is applied to the support, the left plate 2-2 and the right plate 2-3 of the self-resetting system are connected to the anti-buckling system through high-strength bolts, and the support as a whole is in a deformation coordination stage. Due to the application of initial prestress, the SMA pull rod 2-5 is in a tensile state, thereby causing the left plate 2-2, the right plate 2-2 and the inner tube 2-1 to be in a compressive state.

[0050] (2) The support applies a tensile force Ft. The left end plate 3-3 of the support is in a fixed state, and a tensile force Ft is applied to the right end plate 3-4 of the support. If the support is to be in a sliding state under the action of the tensile force Ft, the prestress of the SMA rod 2-5 must be overcome first. The support is in a parallel state as a whole, and its total stiffness is the sum of the stiffness of the SMA rod 2-5 and the inner core 3-8. The tensile state is as follows Fig.10 As shown, as the tension Ft increases, when the tension Ft is greater than the prestress of the SMA rod 2-5, the right plate 2-3 in the self-resetting system will be driven to move to the right under the action of the push rod 2-4, and the SMA rod 2-5 will also be stretched. At the same time, the inner core 3-8 in the anti-buckling system will also be stretched. At this time, the inner core 3-8 is still in the elastic stage although it is in a tensile state. When the tension continues to increase, the relative displacement of the right plate 2-3 and the left plate 2-2 in the self-resetting system continues to increase under the driving action of the push rod 2-4, and the inner core 3-8 in the anti-buckling system first reaches the yield state, and the SMA rod 2-5 is also stretched continuously. At this moment, the stiffness of the support is the stiffness of the SMA rod 2-5.

[0051] (3) Support applies pressure Fc. The left end plate 3-3 of the support is in a fixed state, and the pressure Fc is applied to the right end plate 3-4 of the support. If the support is to be in a sliding state under the action of the tension Fc, the prestress of the SMA rod 2-5 must be overcome first. The support is in a parallel state as a whole, and its total stiffness is the sum of the stiffness of the SMA rod 2-5 and the inner core 3-8. The pressure state is as follows Fig.10 As shown, as the pressure Fc increases, when the pressure Fc is greater than the prestress of the SMA rod 2-5, the left plate 2-2 in the self-resetting system will be driven to move to the left under the action of the push rod 2-4, and the SMA rod 2-5 will also be stretched. At the same time, the inner core 3-8 in the anti-buckling system will also be stretched. At this time, the inner core 3-8 is still in the elastic stage although it is in a tensile state. When the pressure continues to increase, the relative displacement of the left plate 2-2 and the right plate 2-3 in the self-resetting system continues to increase under the driving action of the push rod 2-4, and the inner core 3-8 in the anti-buckling system first reaches the yield state, and the SMA rod 2-5 is also continuously stretched. At this moment, the stiffness of the support is the stiffness of the SMA rod 2-5.

[0052] (4) When the deformation of the support reaches the maximum, the loading is stopped. During the unloading process, under the influence of the restoring force of the SMA rod 2-5, the relative displacement of the left plate 2-2 and the right plate 2-3 in the self-resetting system gradually decreases, and the length of the inner core 3-8 in the anti-buckling system also becomes shorter; as the tension Ft continues to decrease, the distance between the left end plate 3-3 and the right end plate 3-4 also becomes smaller, until the push rod 2-4 contacts the left plate 2-2, and the component returns to its initial state, finally realizing the self-resetting function.

[0053] When the support recovers from the stretched state to the initial state, it proves that the support has completed the self-reset under the tensile force.

[0054] At the same time, after the earthquake, the self-resetting assembled anti-buckling support with built-in SMA pull rod and its various components can be replaced by dismantling high-strength bolts.

[0055] Under the action of an earthquake, the support structure of the present invention can not only effectively dissipate the seismic energy after the earthquake, but also protect the main structure and reduce or even eliminate the residual deformation after the earthquake. Specifically, the seismic energy is dissipated by the double energy-absorbing inner core 3-8 in the anti-buckling system, while the front cover plate 3-1, the rear cover plate 3-2, the upper sleeve 3-5, and the lower sleeve 3-6 enhance the structural stiffness to resist earthquake damage. The SMA pull rod 2-5 in the self-resetting system increases the tension to maintain balance, thereby achieving rapid resetting of the structure and reducing the residual deformation of the structure.

[0056] The SMA tie rod 2-5 is pre-stressed in advance and then fixed with high-strength bolts to keep it in a tensile state at all times. The left plate 2-2, the right plate 2-2 and the inner tube 2-1 are squeezed by the SMA tie rod 2-5, and the self-resetting system is in a balanced state as a whole, thereby increasing the self-recovery ability of the structure.

[0057] The key to achieving self-resetting of the self-resetting assembled anti-buckling support with built-in SMA rod lies in the design of the reset system. If the reset system is not designed reasonably, the following two situations will occur: one is that the cross-sectional area of ​​the SMA rod 2-5 is designed to be large, which will lead to an increase in the total weight of the support and a relatively large price; the other is that the cross-sectional area of ​​the SMA rod 2-5 is designed to be small, and the energy-absorbing core 3-8 in the anti-buckling part will bear a large force, resulting in the front cover plate 3-1, rear cover plate 3-2, upper sleeve 3-5, and lower sleeve 3-6 of the restraining device that restrains the energy-absorbing core 3-8 to bear a large lateral force, and the front cover plate 3-1, rear cover plate 3-2, upper sleeve 3-5, and lower sleeve 3-6 of the restraining device cannot play a restraining effect, resulting in the front cover plate 3-1, rear cover plate 3-2, upper sleeve 3-5, and lower sleeve 3-6 of the restraining device yielding and even deformation, which will greatly affect the reset; therefore, the size of the SMA rod 2-5 should be reasonably designed according to actual conditions.

[0058] Axial design bearing capacity P of fabricated buckling-restrained braces with built-in SMA tie rods n It consists of two parts, mainly the sum of the anti-buckling system and the self-righting system, while the actual bearing capacity P u It is obtained based on structural analysis. Axial design bearing capacity P n , unit is N; actual bearing capacity P u , unit is N; yield bearing capacity N, unit is N; SMA rod prestressing force P m , in N; the yield stress of the inner core F y , unit is N / mm 2 ; Prestress F applied by SMA rod m , unit is N / mm 2 ; The cross-sectional area A of the core plate in the inner core y , unit is mm 2 ; SMA rod cross-sectional area A m , unit is mm 2 ; (1) Support design bearing capacity

[0059] φP n ≥P u (1)

[0060] The design bearing capacity of the support is composed of the inner core 3-8 yield bearing capacity N, SMA tie rod 2-5 prestress P m The sum of the two is calculated as shown in (2):

[0061] φP n =φ(Ν+P m )=0.9(F y A y +F m A m )(2)

[0062] Among them, F y 、F m They represent the yield stress of the inner core 3-8 and the prestress applied by the SMA rods 2-5 respectively;

[0063] A y , A m They represent the longitudinal cross-sectional area of ​​the core plate 3-8-1 in the inner core 3-8 and the cross-sectional area of ​​the SMA tie rod 2-5 respectively;

[0064] φ represents the strength reduction coefficient, and φ=0.9 is taken.

[0065] (2) Prestressing of SMA tie rods 2-5

[0066] F m A m =αsc βωF y A y (3)

[0067] Among them, α sc Represents the ratio of the prestress of the SMA rod 2-5 and the yield strength of the inner core 3-8 after strengthening. The strengthened yield strength refers to the maximum force that the material can withstand after the yield stage, when the load is continued to increase to restore its ability to continue to deform. In order to ensure that the support has a good reset effect, α sc ≥1;

[0068] β represents the compressive strength adjustment coefficient of the inner core 3-8 β=1.2;

[0069] ω represents the strain hardening adjustment factor of the inner core 3-8, ω=1.35;

[0070] (3) Cross-sectional area of ​​the inner core 3-8 and the SMA tie rod 2-5

[0071] According to formulas (1), (2) and (3), the cross-sectional area calculation formula of the core plate 3-8-1 in the inner core 3-8 is shown in (4):

[0072]

[0073] The calculation formula for the cross-sectional area of ​​the SMA tie rod 2-5 is shown in (5):

[0074]

[0075] Example 2

[0076] On the basis of Example 1, the bolts used in the present invention are all high-strength bolts.

[0077] Example 3

[0078] On the basis of Example 2, threads are provided at both ends of the SMA rod 2-5, and nuts are used to fix the two ends of the SMA rod 2-5 on both sides of the right plate and the left plate.

[0079] In order to ensure that the movement trajectories of the reset system and the anti-buckling system are consistent during the force transmission process, the left end of the inner cylinder 2-1 and the pad 3-7, and the right end of the push plate 2-6 and the right end plate 3-4 are fixed by high-strength bolts.

[0080] Example 4

[0081] Based on Example 1, the anti-buckling system is mainly composed of a double inner core and a restraint device, the restraint device includes an upper and lower sleeve, a front cover plate, a rear cover plate, a left end plate, a right end plate and a pad. The left end of the inner core is inserted into the pad and fixed to the left end plate by bolts, and the right side is also fixed to the right end plate by bolts.

[0082] Example 5

[0083] On the basis of Example 4, the front cover plate and the rear cover plate of the present invention are both strip-shaped steel plates with fixing holes a3-10 on the upper and lower sides. Concave notches 3-1-2 are set at the positions of the reinforcing rib plates 3-8-4 at the right ends of the front cover plate and the rear cover plate to allow the inner core 3-8 to have sufficient deformation space.

[0084] Example 6

[0085] On the basis of Example 5, the concave side plates of the upper sleeve are double-layer thin plates, and the concave side plates of the lower sleeve are single-layer plates. The single-layer plates of the lower sleeve 3-6 side plates are inserted between the double-layer plates of the upper sleeve 3-6 side plates, and the single-layer plates of the lower sleeve 3-6 side plates and the double-layer plates of the upper sleeve 3-6 side plates are provided with fixing holes 3-9 corresponding to the fixing holes a3-10, and then fixed by bolts.

[0086] This embodiment uses ABAQUS software to simulate the hysteresis curves of two different supports, the self-resetting assembled anti-buckling brace with built-in SMA pull rods of the present invention and the traditional assembled anti-buckling brace under the same loading system, as shown in FIG. Fig.11 As shown, when the external force is zero, the residual deformation of the assembled anti-buckling brace with built-in SMA rods of the present invention is very small compared with the assembled anti-buckling brace, and has better recoverability. According to the hysteresis loops of the two supports, it can be seen that due to the role played by the SMA rods 2-5 in the pulling and pressing process, the hysteresis loop area of ​​the assembled anti-buckling brace with built-in SMA rods is larger, showing obvious flag characteristics, and the energy dissipation capacity is more significant; under the same displacement, due to the influence of the SMA rods 2-5, the assembled anti-buckling brace with built-in SMA rods has a higher bearing capacity than the assembled anti-buckling brace.

Claims

1. A self-resetting assembled buckling-resistance brace with built-in SMA tie rod, characterized in that: The invention comprises an inner cylinder (2-1), wherein a left plate (2-2) is arranged at the left end of the inner cylinder (2-1), a push rod (2-4) is arranged in series inside the right end of the inner cylinder (2-1), a right plate (2-3) is sleeved on the other end of the push rod (2-4), a push plate (2-6) is arranged on the side of the right plate (2-3) away from the push rod (2-4), and four SMA pull rods (2-5) are arranged on the inner cylinder (2-1) and penetrate from the left end to the right end of the inner cylinder (2-1), and the two ends of the SMA pull rods (2-5) pass through the inner cylinder (2 -1) are fixed to the left plate (2-2) or the right plate (2-3) on the corresponding side, a right end plate (3-4) is also fixed to the right side of the push plate (2-6), a pad plate (3-7) and a left end plate (3-3) are sequentially arranged at the left end of the inner cylinder (2-1), and an inner core (3-8) is symmetrically arranged on the front and rear side surfaces of the inner cylinder (2-1), the right end of the inner core (3-8) is fixed to the right end plate (3-4), and the left end of the inner core (3-8) passes through the pad plate (3-7) and is fixed to the left end plate (3-3).

2. The self-resetting assembled buckling-resistance brace with built-in SMA tie rod according to claim 1, characterized in that: An upper sleeve (3-5) and a lower sleeve (3-6) are respectively arranged above and below the inner cylinder (2-1); one end of the upper sleeve (3-5) and the lower sleeve (3-6) close to the pad (3-7) is fixed on the pad (3-7); and the front and rear sides of the upper sleeve (3-5) and the lower sleeve (3-6) are respectively fixedly connected by a front cover plate (3-1) and a rear cover plate (3-2).

3. The self-resetting assembled buckling-resistance brace with built-in SMA pull rod according to claim 2, characterized in that: The inner cylinder (2-1) is a rectangular shell-like structure. The inner cylinder (2-1) is provided with middle holes (2-1-1) at both left and right ends along the length direction thereof. A fixing rod (2-2-1) is provided in the middle of one side of the left plate (2-2) close to the inner cylinder (2-1) and is perpendicular to and integral with the left plate (2-2). The fixing rod (2-2-1) extends into the middle hole (2-1-1) at the left end of the inner cylinder (2-1). One end of the pushing rod (2-4) extends into the middle hole (2-1-1) at the right end of the inner cylinder (2-1). 2-1-1) and is pressed against the fixing rod (2-2-1), a fixing cylinder (2-3-1) is provided in the middle of one side of the right plate (2-3) close to the inner cylinder (2-1) and is perpendicular to and integral with the right plate (2-3), the other end of the push rod (2-4) is fixed to the fixing cylinder (2-3-1) by threaded connection, a threaded hole (2-3-2) is provided in the center of one side of the right plate (2-3) close to the push plate (2-6), and the push plate (2-6) is close to the right plate (2-3) and corresponds to the threaded holes ( A threaded rod (2-6-1) is arranged at the position of the push plate (2-3-2), and the threaded rod (2-6-1) extends into the threaded hole (2-3-2) to fix the push plate (2-6) and the right plate (2-3). After installation, the left plate (2-2) and the left end surface of the inner cylinder (2-1) are in contact with each other, and the right plate (2-3) and the right end surface of the inner cylinder (2-1) are in contact with each other. The longitudinal sections of the right plate (2-3) and the left plate (2-2) are adapted to the longitudinal section of the rectangular inner cylinder (2-1). The four SMA pull rods (2-5) The nuts are evenly distributed at the four corners of the rectangular longitudinal section of the inner cylinder (2-1), and pass through the left plate (2-2), the inner cylinder (2-1), and the right plate (2-3) from left to right in sequence, and then extend out of the two ends of the left plate (2-2) and the right plate (2-3) to fix the nuts; the front and rear side surfaces of the inner cylinder (2-1) are extended toward the left and right ends of the inner cylinder (2-1) to form an extension plate (2-1-2) integrally arranged with the inner cylinder (2-1), and the pad (3-7) is fixed on the two extension plates (2-1-2) at the left end of the inner cylinder (2-1).

4. The self-resetting assembled buckling-resistance brace with built-in SMA pull rod according to claim 3, characterized in that: A fixing plate (3-7-1) is arranged at a position corresponding to the two extension plates (2-1-2) on one side of the pad (3-7) close to the inner tube (2-1); the corresponding inner side walls of the two fixing plates (3-7-1) are respectively fitted with the outer sides of the extension plates (2-1-2) on the corresponding side; the pad (3-7) and the inner tube (2-1) are fixed by bolts to the corresponding fixing plates (3-7-1) and extension plates (2-1-2); a groove (3-7-2) adapted to the shape of the inner core (3-8) is arranged in the pad (3-7) at a position corresponding to the inner core (3-8) on the front and rear sides; the left ends of the inner core (3-8) on the front and rear sides pass through the groove (3-7-2) and are respectively fixed to the front and rear sides of the left end plate (3-3).

5. The self-resetting assembled buckling-resistance brace with built-in SMA tie rod according to claim 4, characterized in that: The inner core (3-8) comprises a core board (3-8-1) with a rectangular cross section, and core heads are integrally connected to the core board (3-8-1) at both ends of the core board (3-8-1) along the length direction, and the core head comprises a transition board (3-8-2) integrally connected to the core board (3-8-1) at both ends of the core board (3-8-1) along the length direction, and the transition board (3-8-2) has an isosceles trapezoidal cross section, and the upper side of the isosceles trapezoid of the transition board (3-8-2) is the same as the width of the core board (3-8-1) and is integrally connected to both ends of the core board (3-8-1), and a reinforcing fixing board (3-8-3) with a rectangular cross section is connected to one side of the lower side of the isosceles trapezoid of the transition board (3-8-2), and the width of the reinforcing fixing board (3-8-3) is equal to the width of the lower side of the isosceles trapezoid of the transition board (3-8-2). Similarly, the reinforcing fixing plate (3-8-3) is arranged as a whole with the transition plate (3-8-2), the core plate (3-8-1), the transition plate (3-8-2), and the reinforcing fixing plate (3-8-3) are located on the same plane, and a reinforcing rib plate (3-8-4) perpendicular to the transition plate (3-8-2) is also arranged on the same side of the transition plate (3-8-2) and the reinforcing fixing plate (3-8-3), the reinforcing rib plate (3-8-4) and the transition plate (3-8-2) and the reinforcing fixing plate (3-8-3) are arranged as a whole, and are located on the extension line of the center line of the core plate (3-8-1), the core heads of the left ends of the inner core (3-8) on the front and rear sides pass through the groove (3-7-2) and are respectively fixed on the front and rear sides of the left end plate (3-3), and the core heads of the right ends of the inner core (3-8) on the front and rear sides are fixed on the front and rear sides of the right end plate (3-4).

6. The self-resetting assembled buckling-resistance brace with built-in SMA tie rod according to claim 5, characterized in that: The upper sleeve (3-5) and the lower sleeve (3-6) are both configured as "concave" shell-like structures. The "concave" shapes of the upper sleeve (3-5) and the lower sleeve (3-6) are buckled together to form a rectangular cylindrical structure. A plurality of fixing holes (3-9) are evenly arranged on the "concave" side walls of the upper sleeve (3-5) and the lower sleeve (3-6). Fixing holes a (3-10) are also provided on the front cover plate (3-1) and the rear cover plate (3-2) at positions corresponding to the fixing holes (3-9) of the upper sleeve (3-5) and the lower sleeve (3-6). After the upper sleeve (3-5) and the lower sleeve (3-6) are buckled together, the front cover plate (3-1) and the rear cover plate (3-2) are correspondingly placed on the upper sleeve (3-5) and the lower sleeve (3-6). The front and rear sides of the upper sleeve (3-5) and the lower sleeve (3-6) are fixed by bolts passing through the corresponding fixing holes (3-9) and fixing holes a (3-10) after being buckled. The front and rear sides of the upper sleeve (3-5) and the lower sleeve (3-6) corresponding to the position of the pad (3-7) are also provided with fixing plates a (3-5-1). The fixing plates a (3-5-1) of the upper sleeve (3-5) extend downward to the upper ends of the front and rear sides of the pad (3-7), and the fixing plates a (3-5-1) of the lower sleeve (3-6) extend upward to the lower ends of the front and rear sides of the pad (3-7). The upper sleeve (3-5) and the lower sleeve (3-6) are fixed to the pad (3-7) and the fixing plates a (3-5-1) by bolts.

7. The self-resetting assembled buckling-resistance brace with built-in SMA pull rod according to claim 6, characterized in that: The left end plate (3-3) and the pad (3-7) are fixed by bolts, and the right end plate (3-4) and the push plate (2-6) are fixed by bolts. After the core head at the left end of the inner core (3-8) on the front and rear sides passes through the groove (3-7-2), the reinforcing fixing plate (3-8-3) is fixed to the front and rear sides of the left end plate (3-3) by bolts, and the reinforcing fixing plate (3-8-3) at the right end of the inner core (3-8) on the front and rear sides is fixed to the front and rear sides of the right end plate (3-4) by bolts.

8. The self-resetting assembled buckling-resistance brace with built-in SMA tie rod according to claim 7, characterized in that: The cross-sectional area calculation formula of the SMA pull rod (2-5) in the direction perpendicular to the long axis is as follows: Among them, α sc represents the ratio of the prestress of the SMA rod (2-5) and the yield strength of the inner core (3-8) after strengthening, α sc ≤1, β represents the compressive strength adjustment factor of the inner core (3-8); ω represents the strain hardening adjustment factor of the inner core (3-8), F y 、F m They represent the yield stress of the inner core (3-8) and the prestress applied by the SMA tie rod (2-5) respectively; A y It represents the longitudinal cross-sectional area of ​​the core plate (3-8-1) in the inner core (3-8), and its calculation formula is as follows: Among them, P u The actual axial bearing capacity of the self-resetting assembled buckling-restrained brace with built-in SMA rods satisfies the following formula: φP n ≥P u Among them, P n is the axial design bearing capacity of the self-resetting assembled buckling-restrained brace with built-in SMA rod, and φ represents the strength reduction factor.

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