Numerical Analysis of Residual Stress for Copper Base.pdf

JMEPEG (2010) 19:611–615 ASM International DOI: 10.1007/s11665-009-9530-7 1059-9495/$19.00 Numerical Analysis of Residual Stress for Copper Base Brazed Stainless Steel Plate-Fin Structure Qiaoyun Xie and Xiang Ling (Submitted January 12, 2009; in revised form July 10, 2009) Copper base stainless steel plate-fin structure has been widely used as a heat exchanger in many fields. The nonlinear thermal reaction on the residual stress in brazing process of the plate-fin structure was studied in this paper. A finite element model (FEM) was proposed to simulate the heat transfer and the sequential residual stress generated in the plate-fin and filler metals based on thermal elastic-plastic theory. By the stress distribution in four paths marked in the structure obtained from FEM results, it is found that the maximum residual tensile stress occurs in the brazed joint next to the plate side and a crack would initiate in this region. Also, the first principle stresses of reference nodes were calculated and the conclusion is consistent with the simulation results. These results would provide some constructive instructions in the practical brazing procedure. due to large differences in the thermal expansion coefficients Keywords brazed residual stress, FEM, first principle stress, thermal elastic-plastic will increase the suscept