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推导了Modifled—Ψ法应力测试及其穿透深度的计算公式,并利用它测试了铍环形焊件热影响区和基体材料中的残余应力。对电子束焊接的铍环其焊缝附近外表面为拉应力,内表面为压应力。由于Modified—Ψ法透入深度太大,不能用来测定铍的表层残余应力,引入多波长法成功地测试出了铍环表层的应力及应力随层深的分布。同时针对电子束焊接过程的特点,编写了用于应力场计算的有限元分析程序。运用编写的程序分别对不同尺寸及焊接工艺的三个铍环电子束焊接样品进行了有限元分析,并将计算结果与实测值进行了比较。结果表明:有限元计算结果与实测值吻合得较好,为先期预测焊件中残余应力的大小和分布从而优化焊接工艺提供了参考依据。
The calculation formula of Modifled-Ψ stress test and its penetration depth are deduced. The residual stress in the heat affected zone and matrix of beryllium ring weldment is tested. Beryllium ring welded electron beam welding near the outer surface of the tensile stress, the inner surface of the compressive stress. Due to the penetration depth of modified-Ψ method is too large, can not be used to determine the surface residual stress of beryllium, the introduction of multi-wavelength method successfully tested beryllium ring surface stress and stress distribution with depth. At the same time, according to the characteristics of electron beam welding process, the finite element analysis program for stress field calculation has been programmed. By using the program, the finite element analysis of three beryllium ring electron beam welding samples of different sizes and welding processes were carried out respectively. The calculated results were compared with the measured values. The results show that the calculated results agree well with the measured values, which provides a reference for predicting the size and distribution of residual stress in the weldment and optimizing the welding process.