Assembly connection structure between beam bodies in steel structure building
Technical Field
The invention relates to the field of building structures, in particular to the field of steel structure buildings, and particularly relates to an assembly type connecting structure arranged between beam bodies in the steel structure buildings.
Background
In the field of buildings, the assembled steel structure is a hot point direction for the development of the building industry because a building frame formed by the assembled steel structure has the advantages of light weight, high strength, good earthquake resistance, high construction speed, energy conservation, environmental protection and the like. In the fabricated steel structure, the column-beam connection node is an important component of the fabricated steel structure, which has an important influence on the overall stress performance of the building structure.
In most steel structure buildings, a column beam connecting node adopts a connecting structure form that a section of pre-buried steel beam is arranged on a concrete upright column in advance, and then the middle steel beam is assembled at the end part of the pre-buried steel beam in a welding or bolt connection mode. The looks remote site with pre-buried girder steel and middle girder steel is connected through welded assembly form, has concentrated in welded connection position stress, the problem that steel construction mechanical properties is weak relatively, but also has the scene to the girder steel weld, the difficult operation problem of welding strength, the degree of difficulty between the layer big and unable accurate location. The opposite ends of the pre-buried steel beams and the middle steel beams are assembled through a bolt connection method, the formed steel structure mainly consumes energy through plastic deformation of steel, after strong earthquake, the earthquake damage and the formed damage bring difficulty to repair and follow-up use, and the new requirements of people on the earthquake resistance of the structure can not be met more and more. Therefore, how to enable the steel structure to have good ductility, deformability and energy consumption capability under the action of an earthquake at the node of the beam column is a problem to be solved in the design and construction of the steel structure.
Disclosure of Invention
Aiming at the problems of poor ductility and weak shock resistance of a steel beam connecting structure formed in a steel structure building, the invention provides an assembly connecting structure which can be applied to beam bodies in the steel structure building.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the utility model provides an assembly connection structure between roof beam body in steel construction building, installs including pre-buried girder steel, middle girder steel, bolt pre-buried girder steel with edge of a wing apron and web apron of middle girder steel butt joint position. The embedded steel beams and the middle steel beams are all H-shaped, holes for bolts to pass through are formed in web plate end portions of the steel beams and wing plates distributed on two sides of the web plate, two ends of the flange cover plate correspond to flange free ends of the embedded steel beams and flange free ends of the middle steel beams respectively and are fixed between the two steel beams through bolt sets, and two ends of the web cover plate correspond to web free ends of the embedded steel beams and web free ends of the middle steel beams respectively and are also fixed between the two steel beams through the bolt sets.
The middle part of edge of a wing apron, and correspond to pre-buried girder steel with the position of middle girder steel looks butt joint end is equipped with flexion I. The web cover plate is provided with a buffer structure, the buffer structure can elastically deform when encountering an earthquake and dissipate earthquake energy according to hysteresis characteristics, the purpose of weakening acting force borne by the middle steel beam and the embedded steel beam when the earthquake occurs is achieved, and the beam body can be prevented from easily deforming to damage a floor slab when encountering the earthquake with general strength. After a strong earthquake, the connecting structure is seriously deformed mainly at the bent part I and the buffering structure, and can still keep better rigidity after the earthquake.
Under the embodiment of this patent, with the help of the elastic deformation that I the flexion that sets up on the edge of a wing apron produced to and the elastic deformation that the buffer structure that sets up on the web apron can produce, greatly dissipated the effort that the girder steel bore in the earthquake, including torsion and the tensile force that bears, and then can show the deformation that alleviates the girder steel and take place, avoid causing the harm to the floor. After the earthquake, the connecting part at the connecting structure is deformed, and only the connecting part needs to be replaced in the later repair work. Therefore, the assembly and connection structure between the steel beams provided by the patent enables the connection structure to be rigid under the normal use condition, and when an earthquake occurs, the connection structure can transmit the earthquake energy according to the reliable hysteresis characteristic, and the connection structure can show rigid behavior after the earthquake stops, so that the collapse resistance of the connection structure is improved. And the construction difficulty is low, the occupied space is small, the damage is small under the action of a major earthquake, and the repairable function after the major earthquake and the medium earthquake can be provided.
Under the specific implementation scheme, flexion I is the outer terminal surface of the edge of a wing of relative girder steel to the outside or to the curved arc structure of inboard bending, just when the relative outer terminal surface of the edge of a wing of I relative girder steel of flexion is to the inboard bending, the tip on the edge of a wing is equipped with for flexion I implements the breach of stepping down. The bending part I can be a single-stage arc bending structure or a multi-stage circulating bending structure.
On the premise of not increasing the thickness of the flange cover plate, the adverse effect on the flat rigidity of the plate caused by the arrangement of the bending part I is compensated for the flange cover plate, namely, the connecting structure of the two steel beams is ensured to have enough plane rigidity. Under the specific implementation scheme, cover plates are respectively arranged on the inner end surfaces of the flanges of the steel beams and on the two sides of the web plate of the steel beam. The cover plate is correspondingly arranged below or above the flange cover plate, and the flange cover plate on the same side are fixed on the flange of the steel beam through the same group of bolts. The cover plate spans between the butt ends of the two steel beams, and the thickness of the cover plate is smaller than that of the flange cover plate, preferably not larger than 1/2 of the thickness of the flange cover plate. The apron deviates from and is equipped with along fore-and-aft brace rod on the terminal surface on the edge of a wing to increase the face rigidity of apron, the side middle part of apron is equipped with the stress groove, so that the apron can fracture when certain degree elastic deformation appears in the flexion I of edge of a wing apron, avoids the apron to fracture when edge of a wing apron takes place plastic deformation, so when the apron bears great tensile force, can be in advance of edge of a wing apron fracture. If the adverse effect of the flange cover on the plate surface rigidity of the flange cover caused by the arrangement of the bending part I is complemented in a mode of increasing the thickness of the flange cover, the adverse effect can be caused on the elastic deformation capacity of the bending part I. By the foregoing implementation means, even the thickness of the flange cover plate can be relatively reduced to suitably enhance the elastic deformation response capability of the bending portion i. If the thickness of the flange cover plate is not increased, and the implementation means is not adopted, the connecting rigidity of the connecting structure of the two steel beams can be complemented by increasing the thickness of the web cover plate.
In a specific embodiment, the bending portion i is an arc-shaped structure that is bent along the width direction of the flange on the outer end surface of the flange, and may also be a single-stage arc-shaped bending structure or a multi-stage circular bending structure.
In the above-mentioned embodiment, the bending portion i is bent either in the thickness direction of the flange cover plate or in the width direction of the flange cover plate, or may be bent in both the thickness direction and the plate surface direction of the flange cover plate.
Under the specific embodiment, buffer structure is for setting up the flexion II at web apron middle part, this flexion II correspond pre-buried girder steel with the position of middle girder steel looks butt joint end. Specifically, the method comprises the following steps:
in some embodiments, II court of flexion the web face of pre-buried girder steel with the inboard bending of the relative joint department of web face of middle girder steel, the tip of two webs is equipped with the notch of stepping down for II implementation of flexion.
In some embodiments, the bending portion ii bends toward the outer side of the end, where the web plate surface of the embedded steel beam is opposite to the web plate surface of the middle steel beam.
The bending part II can be a one-stage or multi-stage bending circulation structure in the length direction of the steel beam.
Under the specific implementation scheme, the web apron is equipped with the bar hole that corresponds with the bolt on corresponding to one section of middle girder steel web, and the screw rod of bolt corresponds after the assembly is in the middle part in bar hole, is close to pre-buried girder steel web end relatively better, and this characteristic setting is different from in other embodiments in addition, the web apron is corresponding to be equipped with the hole that corresponds with the bolt on one section of middle girder steel web and be the characteristic of round hole. Therefore, it is supplementary to set up a characteristic, that is, be equipped with the buffer board on the outer terminal surface of web apron, this buffer board bolted connection is in on the web apron, and in the position that corresponds pre-buried girder steel with the end that the middle girder steel is butted sets up flexion III.
It should be noted that the buffer plate is longitudinally arranged and spans between the butt ends of the two steel beams, and the hole arranged on the buffer plate and matched with the bolt is a round hole.
The bending part III on the buffer plate extends along the width direction of the plate surface on the plate surface of the web cover plate.
When having set up flexion II, flexion III just right with flexion II.
Under a specific embodiment, the buffering structure is a buffering plate arranged on the outer end face of the web cover plate, and a strip-shaped hole corresponding to a bolt and arranged on one section of the web cover plate corresponding to the web of the middle steel beam, and a screw of the assembled bolt corresponds to the middle of the strip-shaped hole.
The buffer board is connected on the web apron with bolt ground, and in corresponding pre-buried girder steel with the position of middle girder steel looks butt joint end sets up flexion III.
And the bending part III on the buffer plate extends on the plate surface of the web cover plate along the width direction. The characteristic curve section ii is not included in this embodiment.
Under the specific embodiment, buffer structure include in the web apron corresponds to the bar hole that corresponds with the bolt that is equipped with on one section of middle girder steel web, the screw rod of bolt corresponds after the assembly is in the middle part in bar hole. And a thrust plate and an arc plate.
The thrust plate is installed on the web cover plate through bolts and corresponds to one section of the web of the middle steel beam, and the end part of the web cover plate corresponding to one section of the web of the middle steel beam is retracted inwards.
The both ends of arc are equipped with the ear, correspond two ears and are equipped with the double-screw bolt that both ends were worn to establish to the outer terminal surface of web apron of web both sides, and the tip of double-screw bolt is equipped with the nut and will the arc is pressed on the outer terminal surface of web apron. The arch surface of the arc-shaped plate is in contact with the end surface of one end of the thrust plate extending into the web plate.
The beneficial effect of this patent:
the technical scheme that this patent relates has solved steel construction building shock resistance effectively and has been less strong, the problem that shock-resistant structure occupation space is big, construction operation is difficult. The assembly connection structure is designed to enable the connection structure to be rigid under normal use conditions, when an earthquake occurs, the connection structure can transmit earthquake energy according to reliable hysteretic characteristics, and the earthquake can show rigid behavior after stopping, so that the collapse resistance of the structure is improved, the construction difficulty is low, the occupied space is small, the damage is small under the action of a major earthquake, and the repairable function after the major earthquake can be provided.
Drawings
FIG. 1 is a schematic diagram of a structure according to an embodiment of the present patent.
Fig. 2 is a corresponding structure diagram of the opposite ends of the pre-buried steel beam and the middle steel beam under the embodiment of the patent.
Fig. 3 is a schematic top sectional view of a connection structure between a web cover plate and a web of a steel beam according to the embodiment of the present invention.
Fig. 4 is another schematic structural view of an embodiment of this patent.
FIG. 5 is a third schematic representation of the structure of the embodiment of this patent.
FIG. 6 is a schematic diagram of a fourth configuration of the embodiment of this patent.
Fig. 7 is a schematic diagram of a fifth configuration of the embodiment of this patent.
In the figure: 1 concrete column, 2 pre-buried girder steels, 21 edge of a wing A, 22 web A, the round hole of 221a, 3 middle girder steels, 31 edge of a wing B, 32 web B, the round hole of 321B, 4 edge of a wing apron, 41 flexion I, 411 connection gusset, 5 web apron, 51 flexion II, 52 bar holes, 53 thrust plate, 54 arcs, 541 ear, 542 stud hole, 543 double-screw bolt, 6 notch of stepping down, 7 notch of stepping down, 8 apron, 81 stress tanks, 82 brace rod, 9 buffer board, 91 flexion III, 911 crooked gusset
Detailed Description
The structures, proportions, and dimensions shown in the drawings and described in the specification are for understanding and reading the present disclosure, and are not intended to limit the scope of the present disclosure, which is defined in the claims, and are not essential to the skilled in the art. In addition, the terms "upper", "lower", "front", "rear" and "middle" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the relative positions may be changed or adjusted without substantial technical changes.
As shown in fig. 1 and fig. 4 to 7, the assembly connection structure between the beams in the steel structure building comprises an embedded steel beam 2 with one end pre-arranged in a concrete column 1, an intermediate steel beam 3 butted with one end of the embedded steel beam 2 extending to the outside of the concrete column 1, and a flange cover plate 4 and a web cover plate 5 which are bolted and arranged at the butted position of the embedded steel beam 2 and the intermediate steel beam 3. In the figure, the embedded steel beam 2 and the middle steel beam 3 are both in an H shape, the embedded steel beam 2 comprises a flange A21 and a web A22, the middle steel beam 3 comprises a flange B31 and a web B32, wherein a round hole 221 corresponding to the bolt is formed in the web A22, and a round hole 321 corresponding to the bolt is formed in the web B32.
And a bent part I41 is arranged at the middle part of the flange cover plate 4, corresponding to the position of the butt joint end of the embedded steel beam 2 and the middle steel beam 3. As shown in fig. 1 and 6 to 7, the bent portion i 41 has an arc structure in which the outer end surfaces of flanges (i.e., a flange a21 and a flange B31) of the corresponding steel beams (i.e., the embedded steel beam 2 and the intermediate steel beam 3) are bent inward, and at this time, an abdicating notch 6 for abdicating the bent portion i 41 is provided at the end of the flange. As shown in fig. 4 to 5, the bending portion i 41 has an arc structure that is bent outward with respect to the outer end faces of the flanges (i.e., the flange a21 and the flange B31) of the steel beams (i.e., the embedded steel beam 2 and the intermediate steel beam 3). In the previous figures, the bending portion i 41 can be a single-stage arc bending structure or a multi-stage circulating bending structure.
On the premise of not increasing the thickness of the flange cover plate 4, in order to complement the adverse effect of the flange cover plate 4 on the plate surface rigidity caused by the arrangement of the bending part I41, the connecting structure of the embedded steel beam 2 and the middle steel beam 3 is ensured to have enough rigidity. In a specific embodiment, cover plates 8 are respectively arranged on the inner end surfaces of the flange A21 and the flange B31 and on the front side and the rear side of the web A22 and the web B32. The cover plate 8 is correspondingly arranged below or above the flange cover plate 4, and is fixed on the flange of the steel beam through the same group of bolts with the flange cover plate 4 on the same side. The thickness of the cover panel 8 is less than the thickness of the flange cover panel 4, preferably no greater than 1/2 of the thickness of the flange cover panel 4. Be equipped with on the terminal surface that the apron 8 deviates from the edge of a wing along longitudinal extension (extend along girder steel length direction promptly) brace rod 82, the side middle part of apron 8 is equipped with stress groove 81 for apron 8 can be earlier than edge of a wing apron 4 fracture when bearing great tensile force. If the adverse effect of the flange cover on the leveling rigidity of the flange cover due to the provision of the bent portion i is complemented in a manner of increasing the thickness of the flange cover, the elastic deformability of the bent portion i is adversely affected. By the foregoing implementation means, even the thickness of the flange cover plate can be relatively reduced to suitably enhance the elastic deformation response capability of the bending portion i. If the thickness of the flange cover plate is not increased, and the implementation means is not adopted, the connecting rigidity of the two steel beams at the connecting structure can be complemented by increasing the thickness of the web cover plate 5.
As shown in fig. 1, 6, and 7, the bent portion i 41 extends inward of the outer end surface of the flange (flange a21, flange B31), and a plurality of connecting ribs 411 are provided on the upper end surface of the flange cover 4 at positions where the bent portions i 41 are provided, at intervals in the front-rear direction (a groove extending in the front-rear direction is formed above the bent portion i 41, and the connecting ribs 411 are provided in the groove and extend in the width direction of the groove).
In some embodiments, the bending portion i may also be a structure that extends along the width direction of the flange and is bent into an arc shape on the outer end surface of the flange a or the flange B, and may also be a single-stage arc bending structure or a multi-stage cyclic bending structure. That is, the bent portion i in the drawing extends toward the inner or outer direction of the outer end surface with respect to the outer end surface of the flange, and the extending direction is perpendicular to the outer end surface of the flange. When the bending part I extends along the width direction of the flange, the extending direction of the bending part I is relatively parallel to the outer end face of the flange.
As shown in fig. 1 to 7, a buffer structure is disposed on the web cover plate 5, and the buffer structure can elastically deform when an earthquake occurs to dissipate shock energy according to hysteresis characteristics, so as to significantly weaken acting force borne by the intermediate steel beam 3 and the embedded steel beam 2 when the earthquake occurs.
Under the embodiment of this patent, with the help of the elastic deformation that the I41 curved part that sets up on the edge of a wing apron 4 produced to and the elastic deformation that the buffer structure that sets up on the web apron 5 can produce, greatly dissipated the effort that the girder steel bore in the earthquake, including the torsion and the tensile force that bear, and then can show the deformation that alleviates the girder steel and take place, avoid causing the harm to the floor. After the earthquake, the connecting parts at the connecting structure are deformed seriously, and only the connecting parts need to be replaced in the later repair work.
Therefore, the assembly and connection structure between the steel beams provided by the patent enables the connection structure to be rigid under the normal use condition, and when an earthquake occurs, the connection structure can transmit the earthquake energy according to the reliable hysteresis characteristic, and the connection structure can show rigid behavior after the earthquake stops, so that the collapse resistance of the connection structure is improved. And the construction difficulty is low, the occupied space is small, the damage is small under the action of a major earthquake, and the repairable function after the major earthquake and the medium earthquake can be provided.
The buffering structure that is equipped with on the web apron 5, its specific form is as follows:
as shown in fig. 1 to 5, the buffer structure is a bending part ii 51 disposed in the middle of the web cover plate 5, and the bending part ii 51 corresponds to the position of the opposite end of the embedded steel beam 2 and the intermediate steel beam 3. As shown in the drawings, in some embodiments, the bending portion ii 51 is bent toward the inner side of the end where the plate surface of the web a22 of the embedded steel beam 2 and the plate surface of the web B32 of the intermediate steel beam 3 are opposite (as shown in fig. 3), and the end portions of the two webs are provided with abdicating notches 7 (as shown in fig. 2) for abdicating the bending portion ii 51.
In some embodiments, the bending portion ii may further bend toward the outer side of the end where the web plate surface of the embedded steel beam is opposite to the web plate surface of the middle steel beam. I.e. opposite to the bending direction shown in fig. 3.
When an earthquake occurs, the stress of the two steel beams is absorbed by the bending parts I41 and II through the elastic deformation of the bending structures. The thickness of the flange cover plate is generally smaller than that of the web cover plate, and the flange cover plate generally breaks or relatively deforms greatly before the web cover plate when a strong shock occurs. The setting of the notch 7 of stepping down can make the relative bending part I of bending part II have bigger crooked arc structure, so the energy-absorbing ability is better. The bending part II can be a bending arc structure with one stage (as shown in figure 4) or multi-stage circulation (as shown in figure 5).
As shown in fig. 7, a section of the web cover plate 5 corresponding to the web B32 of the intermediate steel beam 3 is provided with a strip-shaped hole 52 corresponding to a bolt, and a screw of the assembled bolt corresponds to the middle of the strip-shaped hole 52, preferably, is relatively close to the end of the web a22 of the embedded steel beam 2. It should be noted that, unless otherwise specified, in the solution of the patent, the holes that match the bolts are generally circular holes. In some embodiments (such as the embodiment shown in fig. 1), the holes corresponding to the bolts provided on the section of the web cover plate 5 corresponding to the intermediate web are circular holes.
The outer end face of the web cover plate 5 is provided with a buffer plate 9, the buffer plate 9 is connected to the web cover plate 5 in a bolted mode, and a bending portion III 91 is arranged at the position corresponding to the butt joint end of the embedded steel beam 2 and the middle steel beam 3. As shown in fig. 7, the bent portion iii 91 of the buffer plate 9 extends in the width direction of the plate surface on the plate surface of the web cover plate 5. The bending section ii 51 is provided, and the bending section iii 91 faces the bending section ii 51. The web A of the embedded steel beam arranged on the buffer plate 9 is provided with a round hole of a bolt matched hole arranged on the web B of the first-level middle steel beam of the bolt.
Since the holes of the bolts in the section of the web cover 5 on the web B of the intermediate steel girder are strip-shaped holes 52, the bolts in this section have a certain play in the longitudinal direction relative to the web cover. The bolt receives fore-and-aft effort and at first can make the III 91 of flexion of buffer board 9 take place elastic deformation, absorbs the shake ability, so web apron can not take place deformation during the earthquake of general intensity, and the flexion II 51 of web apron can absorb the shake ability with the help of elastic deformation with flexion III 91 simultaneously when meetting the earthquake of well, high strength.
Therefore, under the action of general vibration, the reliable hysteretic characteristic formed by the assembling and connecting structure provided by the patent is utilized to transmit the vibration energy, and the web cover plate 5 cannot be caused to generate plastic deformation. Can absorb the shake ability with the help of the plastic deformation of edge of a wing apron 4 and buffer board 9 when the earthquake takes place, reduce the earthquake and to building girder steel structure's destruction, avoid the roof beam body of girder steel to receive great tensile, and make the floor fracture. It helps improving steel structure building's shock resistance, and this kind of earthquake-resistant structure still has occupation space little, construction easy operation, swift advantage moreover.
Receive strong earthquake effect, even if flange apron 4 fracture, the interval that moves about that exists between can be with the help of bolt and the bar hole, and the bent part III 91 of buffer board 9 has certain tensile deformation stroke, it acts on the web to delay too big vibrations effort, avoid forming violent impact to the assembly connection structure between web and the web apron, and finally can rely on buffer board 9 and web apron 5 dual plastic deformation to implement the energy-absorbing, the antidetonation, help further steel construction to avoid the possibility of collapsing under the strong earthquake effect, promote steel construction building's security performance. After the earthquake damage, the connecting part at the joint of the beam body node is directly replaced, which is beneficial to the smooth repair work after the earthquake.
In a specific embodiment, the bending part II is not arranged in the middle of the web cover plate. At this time, referring to fig. 7, the buffer structure is a buffer plate 9 arranged on the outer end surface of the web cover plate 5, and a strip-shaped hole 52 corresponding to a bolt is arranged on a section of the web cover plate 5 corresponding to the web B32 of the middle steel beam 3, and a screw of the assembled bolt corresponds to the middle of the strip-shaped hole 52. The buffer board 9 bolted connection is in on the web apron 5, and in corresponding pre-buried girder steel 2 with the position of middle girder steel 3 looks butt joint end sets up flexion III 91. The bent portion iii 91 of the buffer plate 9 extends in the width direction of the plate surface on the plate surface of the web cover plate 5.
In the above mentioned solution, one or more curved rib plates 911 may be disposed in the groove of the curved portion iii 91 of the buffer plate 9, as shown in fig. 7. The thickness of the curved rib plate 911 arranged at the position is not easy to be large, and the wavy curved structure of the curved rib plate 911 has at least two circulating valley points (at this time, there is one peak point) or at least two circulating peak points (at this time, there is one valley point). Such an arrangement enables the corresponding capacity of elastic deformation of the curved rib 911 to be faster than the response of the curved portion iii 91, so as to absorb shock energy as early as possible. According to the number of the cycles of the bent rib plate, when the bending part III generates large elastic deformation in the process of encountering strong earthquake, the (part or all of) bent rib plate can be straightened and even broken. If the circulation of bending gusset is more, can not fracture easily after meeting with the medium and strong earthquake, can strengthen the whole support rigidity characteristic of steel construction after the earthquake, more advantageously avoid appearing collapsing.
In a specific embodiment, as shown in fig. 6, the buffering structure includes a strip-shaped hole 52 corresponding to a bolt and provided on a section of the web cover plate 5 corresponding to the web B32 of the middle steel beam 3, a screw of the assembled bolt corresponding to the middle of the strip-shaped hole 52, a thrust plate 53, and an arc plate 54. The thrust plate 53 is bolted to the web deck plate 5 at a section corresponding to the web B32 of the intermediate steel beam 3, and the opposite web deck plate 5 is retracted inwardly (to the left in the figure) at the end corresponding to a section of the web B32 of the intermediate steel beam 3.
Both ends of arc 54 are equipped with ear 541, correspond two ears 541 and are equipped with the double-screw bolt 543 of the outer terminal surface of web apron 5 that both ends were worn to establish to the web both sides setting, and the tip of double-screw bolt 543 is equipped with the nut and will arc 54 is pressed on the outer terminal surface of web apron 5. The web B32 and the end of the web cover plate corresponding to the web B32 are provided with stud holes 542 (which are round holes). The arcuate surface of the arcuate plate 54 contacts the end surface of the thrust plate 53 extending into the web B32, which end surface is provided with an arcuate recessed portion as shown. The web of the steel beam can drive the thrust plate 53 to move and press the arc plate 54 to elastically deform to absorb shock energy, and meanwhile friction generated when the thrust plate slides relative to the web cover plate can also absorb certain shock energy. As shown, the dome top of the arc plate 54 is provided as a thickened portion. The outer wall of the stud 543, with the two ends extending out of the ear portion, is provided with an external thread matched with the nut, and the middle cylindrical surface is a light cylindrical surface, so that rigidity can be kept in the deformation of the arc-shaped plate on the premise that the outer diameter of the stud is not too large, and larger shearing force can be borne.
On the basis of the embodiment shown in fig. 6, a bending part ii can be further provided on the web cover plate.
The bending direction of the bending portion iii 91 shown in fig. 7 is opposite, and the direction may be uniform in other embodiments. And the number of the buffer plates may be one or more.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Many modifications may be made to the present invention without departing from the spirit or scope of the general inventive concept, and it will be apparent to those skilled in the art that changes and modifications may be made to the above-described embodiments without departing from the spirit or scope of the invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.