Study On Connection Behavior Of ALC Wall Panels Externally Attached To Pre-fabricated Steel Frames

Autoclaved Lightweight Concrete(ALC)wall panels are widely used in various prefabricated steel structure buildings due to its excellent building physical properties and good comprehensive economic benefits.However,some cracking problem in the application of ALC wall panels externally attached to prefabricated steel frames have seriously affected the use function and comfort of the building,which is not conducive to the wide application of this lightweight panel with good performance.As an important part of the wall panel,the connection between the ALC panel and the steel frame has a significant impact on the performance of the wall panel.Most of the existing studies focus on the ALC wall panel performance when it is subjected to out-of-plane loads,and there are relatively few studies on the wall panel performance when the wall panel is subjected to inter-story displacement of the structure.However,the analysis of the cracking phenomenon of the ALC wall panel shows that in addition to the out-of-plane loading,the inter-story displacement is also an important reason for the cracking of the ALC wall panel.In response to this problem,this paper takes the ALC wall panel with bolt fixed connection which is widely used in China as the object,uses numerical analysis method to study the working performance of the wall panel connection and the surrounding area during the service stage,analyzes the deep-seated reasons and influencing factors of the ALC wall panel cracking,and puts forward the improvement suggestions and design methods for the existing connection.The numerical analysis method is used to study the stress state,deformation characteristics and the failure mode of the wall panel connections when the interstory displacement of the main structure reaches the limit of the service stage and the connection parameters or installation position are under adverse working conditions.Single factor analysis and orthogonal analysis were used to study the influence of the length,width,thickness of the support plate and the diameter of the fixing bolt on the connection performance,as well as the main parameters affecting the connection performance and the interaction between the parameters.Suggestions on the value of connection key parameters are proposed,and the optimal level of each parameter is determined and the performance of the optimal parameter level connection is verified.The design methods of the high-deformation adaptive connection and the curved plate sliding connection of the ALC wall panel are proposed,and the restraining effects of the new connection and the original bolt fixed connection on the in-plane rotation of the wall panel are compared.When the inter-story displacement of the main structure reaches the limit of service and the connection parameters or installation position are in unfavorable conditions,the bolt fixed connection has a strong restriction on the rotation of the wall panel,and the connection and the corresponding parts of the wall panel will have different degrees of failure or damage.The in-plane restraint effect of the wall panel increases with the increase of the length,thickness of the support plate and the diameter of fixing bolt.The length of the support plate and the diameter of the fixing bolt are the main parameters that affect the restraint effect of the connection on the wall panel,and the interaction between the parameters has no significant impact on connection performance,and the parameter-optimized connection restricts the inplane rotation of the wall panel significantly less than the original connection.The restraint effect of high deformation adaptive connection and arc-shaped plate sliding connection on the inner rotation of the wall plate is significantly less than that of the existing fixed bolt connection,which solves the problem of cracking and crushing of the connection part when the wall plate is subjected to the inter-story displacement of the main structure in the service stage.The high-deformation adaptive connection and the curved panel sliding connection of the ALC wall panel have a significantly less restrictive effect on the in-plane rotation of the wall panel than the existing bolt fixed connection.which solves the problem of cracking and crushing of the connection part when the wall plate is subjected to the inter-story displacement of the main structure in the service stage.