Study on stiffness degradation of aluminium alloy plate joints at high temperatures and its effect on fire resistance of mesh structures
The finite element numerical simulation analysis method was used to study the bending stiffness degradation mechanism of aluminum alloy plate joints at 200～400℃.The bending stiffness degradation reduction coefficients corresponding to different temperatures were given,and the failure modes of the joints were analyzed.The analysis results show that the local deformation of the upper gusset plate is obvious,the lower gusset plate has tensile-shear failure,the flange plate breaks along the surrounding bolt holes,and the stress concentration position of the web gradually develops downward as the temperuture rises and the web fractures.On the basis of the above,through the case study of a typical aluminum alloy mesh structure,the influence of bending stiffness degradation of the joints on the structural overall fire resistance was studied.The results show that at high temperature,compared to the mesh structure without considering bending stiffness degradation of the joints,the deformation of the mesh structure with considering bending stiffness degradation of the joints is more concentrated in the high temperature area,and the vertical deformation increases by 4.5%,the vertical bearing capacity decreases by 46%.The bending stiffness degradation of joints has obvious influence on the analysis of structural fire resistance,and it should be considered in the overall fire resistance analysis of aluminum alloy structures.
NETL
NSTL
万方数据
维普
