Finite Element Analysis Of Residual Stress In Brazed Stainless Steel Sandwich Panel

Compared with ordinary steel,stainless steel materials have the advantages of good durability,good corrosion resistance and low maintenance cost.In order to give full play to the advantages of stainless steel materials,and obtain a greener,environmentally friendly,economical and applicable new building structural material,drawing lessons from the honeycomb plate structure which is widely used in the aviation field,Yuanda Construction Technology Company independently developed the stainless steel core plate structure,which is a kind of stainless steel core plate structure.The new building structure system has the advantages of light weight,high strength and assembled construction.The stainless steel core plate uses S304 stainless steel sheet as the upper and lower layers.S304 stainless steel thin-walled core tube is densely distributed between the upper and lower layers according to a certain distance,and then the panel and core tube are connected into a solid whole through copper brazing.Although the cooling process of brazing is very slow,because the base metal and brazing filler metal are different,there will still be higher residual stress at the brazing seam.Based on the theory of thermo-elastic-plastic and finite element software ABAQUS,the size and distribution of residual stress in stainless steel core plate brazing are studied by finite element analysis method.The specific work is as follows:(1)The characteristics and brazing technology of stainless steel and copper are briefly introduced.The knowledge of residual stress and the research progress of finite element analysis are summarized.(2)The finite element method,thermo-elastic-plastic theory,basic theory of heat transfer and welding stress-strain theory are briefly introduced.(3)This paper introduces the actual production process of stainless steel core plate,and combines the process to make a reasonable simplifying assumption for finite element analysis.Based on the whole-to-local research ideas,three different finite element three-dimensional models are established to study the core plate.The size and distribution of the residual stress of the brazing,and then establish a two-dimensional axisymmetric model to accurately study the size and distribution of the residual stress in the local area of the brazed joint,the correctness of the two-dimensional axisymmetric finite element model in this paper is verified by citingthe experimental results in the relevant literature;(4)According to the actual production needs,several groups of finite element models were established to study the parameters of brazing residual stress.The following eight factors were investigated: filler metal thickness,core tube thickness,panel thickness,core tube diameter,core tube spacing,lap width,brazing temperature and types of filler metal.