Study On Seismic Performance Of Flexible Connection AAC Wallboard And Steel Frame

The traditional construction industry faces drawbacks such as low production efficiency,high resource consumption,and severe environmental pollution,which do not meet the national requirements for the development of green and energy-saving buildings.Developing green and energy-saving building materials is an inevitable direction for future building development.AAC wall panels(Autoclaved Aerated Concrete,AAC)have many advantages such as lightweight,fire and sound insulation,and high installation efficiency,making them a green and environmentally friendly material vigorously promoted by the country.AAC wall panels are commonly used as infill wall materials in steel structure buildings in China.At the same time,in order to eliminate the drawbacks of traditional rigid connections between walls and structures(stiffness effects),this paper designs a new type of seismic node suitable for flexible connection systems.This node can be used to connect AAC wall panels to the main structure or AAC panels.Three scaled flexible connection AAC wall panels to steel frames were subjected to pseudo static tests,and a finite element model similar to the test was established using the finite element software ABAQUS,The rationality of the model and finite element method was verified,and parameter analysis was conducted to obtain the following conclusions:(1)In this flexible connection system,compared to the empty frame specimen,the ultimate bearing capacity of the fully laid flexible connection AAC wall panel steel frame increased by7.16%,indicating that the addition of AAC wall panels can improve the structural bearing capacity.The peak bearing capacity of the specimen with openings is basically the same as that of KKJ,which is due to the out of plane displacement of the specimen with openings during experimental loading,resulting in lower failure displacement and ultimate load of the specimen.The initial stiffness of the three specimens is the same,but the degradation rate in the early stage is different,while the trend of stiffness degradation in the later stage is consistent.The addition of AAC wall panels can significantly increase energy consumption and improve ductility,and the increase in full masonry specimens is greater than that of specimens with openings.(2)In this flexible system,AAC wall panels can undergo collaborative deformation with the steel structure through the rotation of node sliding plates and the sliding of bolts in the long circular holes of the sliding plates.The large deformation space of AAC wall panels only causes slight damage to the wall panels under large earthquake loads,and the steel structure also exhibits good plasticity.The steel frame does not undergo significant cracking,but excessive deformation makes the structure unable to continue loading.Therefore,the ultimate displacement angle of the system is given as 1/20.(3)From the perspective of the failure of non structural components,this flexible connection can not only improve the problem of traditional rigid connected walls experiencing more cracks in the early stages of earthquakes due to the strong "stiffness effect",but also improve the problem of traditional flexible connected walls experiencing more severe wall damage after the interlayer displacement angle reaches 1/50.Under this flexible connection system,the AAC wall panel can not only meet the seismic fortification index of "no damage during small earthquakes,no collapse during large earthquakes",but also ensure that when the interlayer displacement reaches 1/20,the AAC wall panel is almost intact,with only slight damage occurring locally,and the nodes are also intact,reflecting the superiority of the seismic performance of this flexible connection system and the new type of nodes.(4)Using ABAQUS finite element analysis software,a finite element model was established that was the same as the experiment.The model failure morphology,hysteresis curve,skeleton curve,bearing capacity,and other aspects were compared with the experimental results.The model data were in good agreement with the experimental data,and the bearing capacity error did not exceed 5%.By comparing the stress nephogram of the finite element results with the test failure phenomenon,the finite element results can more accurately describe the stress development trend,failure characteristics and deformation characteristics of the steel frame and AAC wallboard,and the AAC wallboard can cooperate with the steel frame through sliding friction.(5)The ABAQUS finite element analysis software was used to conduct parameter analysis on the flexible connection AAC wall panel steel structure,exploring the effects of connection form,axial compression ratio,hole ratio,hole ratio,and other factors on the seismic performance of the structure.Compared with traditional rigid connection methods,the use of this flexible connection system can improve the adverse interaction between AAC wall panels and frames,change the force transmission mechanism and deformation mode between AAC wall panels,and enable AAC wall panels to deform synergistically with the main structure under large deformation.Moreover,the damage of the infill wall with flexible connection occurs later,and the development of wall damage is relatively small,improving the in-plane seismic performance of the structure,Contribute to the overall performance of the structure.For flexible connection structures,increasing the axial compression ratio can improve the seismic performance of the structure.The opening of openings helps to improve the ductility of the structure,but reduces the bearing capacity.Moreover,the opening of window openings has a slight impact on the system.