Use Finite Element Method For Analyzing The Deformation Of Steel Structure Caused By Weld

Welding deformation is an unavoidable problem in process of production and installation of steel structure, and it will cause certain harmfulness against quality of steel structure. With wide application of the steel structure in construction field, welding deformation problems of building steel structure is increasingly outstanding. Make accurate prediction of welding deformation is the key of effective control of welding deformation. Great progress has been made in study of prediction method of welding deformation at present, but existing research results mainly focus on mechanical manufacturing field. Although these methods can perform high analysis and prediction accuracy, but they put forward high demands on calculation conditions, computational cost, knowledge level of technicians and other aspects. Because of this, these methods cannot be widely used in building steel structure field.This paper presents a more simple, more effective, more easily to be use finite element method to analyze welding deformation of steel structure. First, the method take the characteristics and essence of welding deformation as a basis, and decompose the whole welding and temperature variation process into superposition of multiple step by step states simply .Secondly, the method use simple temperature functions ,introduce conception of temperature load, and translates element temperature variation into equivalent joint load of element. This can avoid complex and difficult to master calculation of heat conduction and thermodynamic. Thirdly, the method use new quality finite element as analysis tools to keeping analysis precision. The new quality finite elements have advantages of simple formulation, high precision, strong adaptability and good convergence. In addition, temperature load formulae, element stiffness equation and stress calculation formula of new finite elements is derived, so as to analysis and use.After complete the theoretical method which analyze welding deformation by finite element method, this paper use FORTRAN 90 language to compile corresponding finite element program, in order to achieve the purposes of solving practical engineering problems by this method. Combining with an example, contrast between the analysis of this method and SAP2000, the comparison results show that this method is correct and effective. Finally, analyze welding deformation of a specific example in different welding sequence by this method. According to the analysis, we can see that the method not only can be used to analyze welding deformation, but also is a powerful optimization tool of weld in building steel structure field.