试样尺寸对Al_2O_3陶瓷/Nb钎焊接头应力场分布的影响

Effect of Specimen Size on the Residual Stress of Al_2O_3 and Nb Brazed Joint

采用数值模拟的方法研究了试样尺寸对Al2O3陶瓷和Nb 钎焊接头残余应力场分布的影响,研究发现试样尺寸变化会对接头的残余应力场产生一定的影响。当试样尺寸在高度H 方向上不断增加时,残余应力分布趋势基本不变,只是应力峰值有所增加,且当高度H 增加到一定值时(在本研究中H=10 mm),其变化不再影响残余应力的分布,应力峰值不再增加。当试样尺寸在宽度W 方向上增加时,残余应力也是呈现不断增加的趋势,当试样宽度W 增加到25 mm后,残余应力峰值开始下降。所以适当增加试样尺寸可有效降低试样中残余应力分布,对接头设计有益。

Effect of specimen size on the residual stress distribution of Al2O3/Nb joint is studied using numerical analysis. It can be concluded that the difference of specimen size can greatly influence the stress distribution. When the height of the specimen increased, the residual stress did not change evidently, and the residual would not change any more with the height increased to some degree with the width of specimen increasing, the residual stress increased firstly. But when the width reached 25 mm, the residual stress decreased instead. In conclusion, increasing specimen size is beneficial to both residual stress decrease and structure design in practice.