The Numerical Simulation Based On ABAQUS For Tapping Screw In Cold-formed Steel Framed Shear Wall Assemblies

For the sake of light weight,high strength,high stiffness,easy assembly and recyclability,cold-formed steel structure are more and more widely used.The cold-formed steel shear wall is the most important load-bearing structure in the cold-formed steel structure.It is assembled by a huge number of tapping screws,and its mechanical characteristics have great impact on the mechanical characteristics of the assembled wall.Therefore,the simulation of self-tapping screw is the key issue in finite element analysis of the cold-formed steel shear wall.Based on the previous research,it is found that there are few researches on the finite element analysis of the self-tapping screw connection,and the model used for the simulation has some shortcomings.The objective of this dissertation is to provide a new finite element model designed on ABAQUS platform,which is suitable for simulating the connection of self-tapping screws in cold-formed steel shear wall.This dissertation is consisted of four main parts:First of all,based on the experimental phenomenon of cold-formed steel shear wall,the mechanical characteristics of self-tapping screw connection are summarized.It is found that the nonlinear behavior of self-tapping screw connection is caused by translation slip and rotation slip.Finally,the function required on the new finite element model is revealed.Secondly,the new finite element model of the self-tapping screw connection is designed according to the required functions obtained from the previous stage.The new FEA model is named as the Connector-Spring Model which is consisted of the connector element and nonlinear spring element.Function of the proposed Connector-Spring Model is verified with comparisons of a series of experiments and corresponding finite element analysis.Then,in order to improve the modeling efficiency of the proposed Connector-Spring Model,a Python script is designed to automatically generate the Connector-Spring Model in ABAQUS.In addition,parametric design is introduced to improve the modeling efficiency of the cold-formed steel shear wall.Finally,aiming at simulation on the rotation slip effect of the self-tapping screw connection in the steel sheet sheathing shear wall,an asymmetric UEL model is provided to replace the Connector-Spring Model.