Study On Bending Performance Of Light Steel Keel-ALC Sandwich Composite External Wall Panel

Under the background of "double carbon",China vigorously develops prefabricated building.As an important part of prefabricated building,prefabricated exterior wall panels have great development space.In order to meet the demand for load-bearing capacity of wall panels and highlight their insulation properties,prefabricated composite wall panels have emerged.The light steel keel composite wall panel with a light steel keel as the skeleton stands out due to its lightweight and high strength.In order to optimize the structural form and mechanical performance of light steel keel composite wall panel and promote the development of prefabricated building,this thesis proposes a new type of composite sandwich external wall panel by adding lightweight insulation core materials to the light steel keel-ALC panel,and conducts a study on the bending performance of the light steel keel-ALC composite sandwich external wall panel with ALC panel(autoclaved lightweight concrete)as the cladding panel on both sides,light steel keel as the middle skeleton,and filled with insulation core materials.The main research content and conclusions of this thesis are as follows:(1)Conduct ALC panel performance tests,bending performance tests,and bending performance tests on light steel keel-ALC composite sandwich external wall panel.The test results show that the strength grade of the ALC panel is A5.0 and the dry density grade is B06.The failure mode of the ALC panel bending test is limited reinforcement failure,with cracks concentrated within a quarter of the support span and symmetrically distributed.The failure mode of the composite wall panel bending test is the cracking failure of the ALC panel,accompanied by the ALC panel being pulled out of the self tapping screw.The wall panel meets the requirements of the allowable deflection L/200 specified for normal use load and the allowable deflection L/50 specified for ultimate load.(2)Establish finite element model of light steel keel-ALC composite sandwich external wall panel using finite element software and conduct parameter analysis.Select appropriate material constitutive relationships,element types,etc.and establish a bending test wall panel model.The finite element simulation and experimental results are relatively consistent,verifying the correctness of the finite element model.Establish a total of 31 finite element models of composite wall panels with different strength levels and other conditional parameters,and analyze the impact of different parameters on the bending performance of composite wall panels.The results show that with the increase of ALC panel strength,ALC panel thickness,keel web height,and keel thickness,or the decrease of vertical keel spacing and self tapping screw spacing,the bending bearing capacity of composite wall panels significantly increases.The strength of light steel keel has an impact on the later bending bearing capacity of composite wall panels.The horizontal and vertical laying of ALC panels have little impact on the bending bearing capacity of composite wall panels.Therefore,horizontal laying of ALC panel can be considered to flexibly select the spacing between vertical keels.Adding tie bolts can improve the bending bearing capacity of composite wall panels,and can also improve the situation where there is a significant difference in force between the ALC panels on both sides.(3)Study the calculation method for the flexural bearing capacity of light steel keel-ALC composite sandwich external wall panel,and provide design suggestions for composite wall panel.Calculate the cracking moment,ultimate bending bearing capacity,and comparison of the ALC panel,calculate the bending bearing capacity and deflection of the light steel keelALC composite sandwich external wall panel under the vertical and horizontal laying of the ALC panel,and compare them with experimental results and finite element simulation results.The error is within ±10%,effectively verifying the applicability of this bending calculation in the light steel keel-ALC composite sandwich external wall panel.According to the analysis results,suggestions are made for the design of the light steel keel-ALC composite sandwich external wall panel,which provides reference for the application of the light steel keel-ALC composite sandwich external wall panel.