钎焊降温速率对板翅结构钎焊残余应力和等效热变形的影响规律

Effect of cooling rate on residual stress and equivalent thermal deformation of brazed plate-fin structures

为了研究不同钎焊降温速率对板翅结构内部的钎焊残余应力和等效弹性热应变的影响规律.建立了板翅结构的三维热应力分析模型,采用热-结构耦合的方法,模拟分析了不同钎焊降温速率下,钎焊残余应力和等效弹性热应变的变化情况.研究结果表明:板翅结构内部的钎焊残余应力随着钎焊降温速率的减小而减小;不同钎焊降温速率下,板翅结构内部的钎焊残余应力之间的差值也不同,当钎焊降温速率小于某一值时,板翅结构内部的钎焊残余应力的大小将近似为定值;钎焊降温速率越小,板翅结构内部薄弱部位发生断裂的风险性就越小;钎焊降温速率对板翅结构的等效弹性热应变的影响较小.

In order to study the effect of different brazing cooling rate on the brazing residual stress and equivalent elastic thermal strain of plate-fin structure,a three-dimensional thermal stress analysis model of plate-fin structure is established,and the variation of brazing residual stress and equivalent elastic thermal strain under different brazing cooling rates are simulated and analyzed using the thermal-structural coupling method.The results show that the brazing residual stress of fin-structure is decreased with the decrease of the brazing cooling rate.The difference between the brazing residual stresses of the plate-fin structure is also different for different brazing cooling rates,and when the brazing cooling rate is less than a certain value,the brazing residual stress of the plate-fin structure will be approximately constant.The smaller the brazing cooling rate,the smaller the risk of fracture in the weak parts of the plate-fin structure.The brazing cooling rate has little effect on the equivalent elastic thermal strain of the plate-fin structure.