Ultrasonic impact treatment (UIT) is an effective method that has been widely applied in welding structure to improve the fatigue properties of materials. It combines mechanical impact and ultrasonic vibration to produce plastic deformation on the weld joints surface, which introduces beneficial compressive residual stress distribution. To evaluate the effect of UIT technology on alleviating the residual stress of welded joints, a novel numerical analysis method based on the inherent strain theory is proposed to simulate the stress superposition of welding and subsequent UIT process of 304 stainless steel. Meanwhile, the experiment according to the process was carried out to verify the simulation of residual stress values before and after UIT. By the results, optimization of UIT application could effectively reduce the residual stress concentration after welding process. Residual tensile stress of welded joints after UIT is transformed into residual compressive stress. UIT formed a residual compressive stress layer with a thickness of about 0.13 mm on the plate. The numerical simulation results are consistent with the experimental results. The work in this paper could provide theoretical basis and technical support for the reasonable evaluation of the ultrasonic impact on residual stress elimination and mechanical properties improvement of welded joints.

中文翻译：

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超声波冲击处理对焊接残余应力影响的数值模拟

超声波冲击处理（UIT）是一种有效的方法，已广泛应用于焊接结构中，以改善材料的疲劳性能。它结合机械冲击和超声波振动在焊接接头表面产生塑性变形，从而引入有益的压缩残余应力分布。为评价UIT技术对减轻焊接接头残余应力的效果，提出一种基于固有应变理论的新型数值分析方法，用于模拟304不锈钢焊接及后续UIT过程的应力叠加。同时，根据该工艺进行实验，验证UIT前后残余应力值的模拟。根据结果​​，优化UIT应用可有效降低焊接后残余应力集中。UIT后焊接接头的残余拉应力转化为残余压应力。UIT在板上形成了厚度约为0.13 mm的残余压应力层。数值模拟结果与实验结果一致。本文的工作可为合理评价超声波对焊接接头残余应力消除和力学性能改善的影响提供理论依据和技术支持。数值模拟结果与实验结果一致。本文的工作可为合理评价超声波对焊接接头残余应力消除和力学性能改善的影响提供理论依据和技术支持。数值模拟结果与实验结果一致。本文的工作可为合理评价超声波对焊接接头残余应力消除和力学性能改善的影响提供理论依据和技术支持。