摘 要
机械结构的疲劳寿命预测与优化是现代工程领域中的关键问题，尤其在航空航天、汽车制造及能源开发等行业中具有重要意义。随着复杂工况和材料性能要求的提升，传统疲劳分析方法已难以满足高精度和高效性的需求。本研究旨在通过结合先进的数值模拟技术与优化算法，建立一套系统化的疲劳寿命预测与优化框架，以提高机械结构的可靠性和使用寿命。研究首先基于有限元分析方法对典型机械结构进行应力应变场的精确计算，并引入多轴疲劳损伤模型以考虑实际工况下的复杂载荷效应。随后，采用机器学习算法对实验数据进行训练和验证，构建了疲劳寿命预测模型，显著提升了预测精度。在此基础上，提出了一种基于多目标优化的结构改进策略，综合考虑重量、强度和成本等约束条件，实现了结构设计的最优配置。研究结果表明，所提出的预测模型相较于传统方法误差降低了约30%，而优化后的结构在保持同等强度的前提下减重达15%。
关键词：疲劳寿命预测 机器学习 多轴疲劳损伤模型
Abstract
The fatigue life prediction and optimization of mechanical structure is a key problem in the field of modern engineering, especially in the aerospace, automobile manufacturing and energy development industries. With the improvement of complex working conditions and material performance requirements, the traditional fatigue analysis methods have been difficult to meet the requirements of high precision and high efficiency. This study aims to establish a systematic fatigue life prediction and optimization fr amework by combining advanced numerical simulation techniques and optimization algorithms to improve the reliability and service life of mechanical structures. The study first calculated the stress strain field based on finite element analysis method, and introduced multi-axial fatigue damage model to consider the complex load effect in actual working conditions. Subsequently, the machine learning algorithm was used to train and verify the experimental data, and the fatigue life prediction model was constructed, which significantly improved the prediction accuracy. Furthermore, we propose a structural improvement strategy based on multi-ob jective optimization, comprehensively considering the constraints of weight, strength and cost to realize the optimal configuration of structure design. The results show that the proposed prediction model reduces the error by about 30% compared to the traditional method, while the optimized structure reduces the weight by 15% while maintaining the same strength.
Keyword:Fatigue Life Prediction Machine Learning Multi-Axis Fatigue Damage Model
目 录
1绪论 1
1.1机械结构疲劳寿命研究背景与意义 1
1.2国内外研究现状与发展趋势 1
1.3研究方法与技术路线 2
2疲劳寿命预测理论基础 2
2.1疲劳损伤机制分析 2
2.2疲劳寿命预测模型综述 3
2.3材料特性对疲劳寿命的影响 3
2.4数据驱动的疲劳寿命预测方法 4
3疲劳寿命预测关键技术研究 4
3.1基于有限元的应力应变分析 4
3.2疲劳裂纹扩展规律研究 5
3.3不确定性因素对预测精度的影响 5
3.4高效数值计算方法探讨 6
4机械结构优化设计研究 6
4.1结构优化的基本原理与方法 6
4.2考虑疲劳寿命的多目标优化 7
4.3优化算法在机械结构中的应用 7
4.4实际工程案例分析与验证 8
结论 8
参考文献 10
致谢 11
