摘要
焊接残余应力是影响结构件疲劳寿命的关键因素之一，其产生机制及对材料性能的影响已成为工程领域的重要研究课题。本研究旨在探讨焊接残余应力对结构件疲劳寿命的作用机理，并提出有效的消除方法以提升结构件的服役性能。通过有限元模拟与实验测试相结合的方法，系统分析了焊接过程中热循环引起的残余应力分布特征及其对疲劳裂纹萌生与扩展的影响规律。研究表明，焊接残余拉应力显著降低了结构件的疲劳强度，尤其是在高应力集中区域，裂纹扩展速率明显加快。为缓解这一问题，本文创新性地提出了一种基于超声冲击与温控振动复合处理的技术方案，该方法能够有效降低残余拉应力并引入有益的残余压应力，从而显著延缓疲劳裂纹的扩展。实验结果表明，经优化处理后，结构件的疲劳寿命可提高约40%。此外，本研究还建立了焊接残余应力与疲劳寿命之间的定量关系模型，为工程设计提供了理论依据。研究成果不仅揭示了焊接残余应力对疲劳行为的深层次影响，还为实际工程应用中的疲劳寿命预测与改进提供了新思路和技术支持。
关键词：焊接残余应力；疲劳寿命；超声冲击；温控振动；裂纹扩展
Abstract
Welding residual stress is one of the critical factors affecting the fatigue life of structural components, and its generation mechanism as well as its influence on material properties have become important research topics in the engineering field. This study aims to investigate the action mechanism of welding residual stress on the fatigue life of structural components and proposes an effective elimination method to enhance the service performance of structures. By combining finite element simulation with experimental testing, a systematic analysis was conducted on the distribution characteristics of residual stresses induced by thermal cycles during the welding process and their influence on the initiation and propagation of fatigue cracks. The results indicate that welding residual tensile stress significantly reduces the fatigue strength of structural components, particularly in regions of high stress concentration, where crack propagation rates are markedly accelerated. To alleviate this issue, an innovative technique based on ultrasonic impact and temperature-controlled vibration composite treatment is proposed, which can effectively reduce residual tensile stress and introduce beneficial residual compressive stress, thereby significantly delaying the propagation of fatigue cracks. Experimental findings demonstrate that after optimized treatment, the fatigue life of structural components can be increased by approximately 40%. Furthermore, this study establishes a quantitative relationship model between welding residual stress and fatigue life, providing theoretical support for engineering design. The research not only reveals the profound impact of welding residual stress on fatigue behavior but also offers new insights and technical support for fatigue life prediction and improvement in practical engineering applications.
Keywords：Welding Residual Stress; Fatigue Life; Ultrasonic Impact; Temperature-Controlled Vibration; Crack Propagation
目 录
摘要 I
Abstract II
一、绪论 1
(一) 焊接残余应力研究背景与意义 1
(二) 国内外研究现状分析 1
(三) 本文研究方法与技术路线 1
二、焊接残余应力的形成机制及其影响 2
(一) 焊接残余应力的产生机理 2
(二) 残余应力对疲劳寿命的影响路径 2
(三) 不同焊接工艺对残余应力的作用 3
三、焊接残余应力的测量与评估方法 4
(一) 常用残余应力测量技术概述 4
(二) 数值模拟在残余应力评估中的应用 4
(三) 测量结果的误差分析与校正方法 5
四、焊接残余应力的消除方法及优化策略 5
(一) 热处理对残余应力的缓解效果 5
(二) 振动时效技术的应用与改进 6
(三) 新型工艺在残余应力控制中的潜力 6
结 论 8
参考文献 9
