摘要
金属材料在工程应用中面临着复杂的交变载荷环境，其疲劳寿命预测对于确保结构安全性和可靠性至关重要。本研究旨在建立一种高效准确的金属材料疲劳寿命预测方法，并通过实验验证其有效性。基于此目的，本文首先分析了传统疲劳寿命预测模型的局限性，提出了一种结合微观组织特征与宏观力学性能的多尺度预测模型。该模型引入了位错密度、晶粒尺寸等微观参数作为输入变量，同时考虑了加载频率、温度等环境因素的影响。通过有限元模拟和实验测试相结合的方式，对不同工况下的金属试样进行了系统研究。实验部分采用旋转弯曲疲劳试验机，针对多种典型金属材料（包括低碳钢、铝合金和钛合金）进行了一系列疲劳试验，获得了丰富的应力-寿命数据。结果表明，所提出的多尺度模型能够更准确地描述金属材料在不同条件下的疲劳行为，预测误差较传统模型降低了约30%。此外，通过对失效模式的深入分析，发现微观组织演变与宏观疲劳损伤之间存在显著相关性，为理解材料疲劳机制提供了新的视角。本研究不仅提高了疲劳寿命预测精度，还为优化材料设计和选型提供了理论依据，具有重要的工程应用价值。
关键词：金属材料疲劳寿命预测；多尺度模型；微观组织特征
Abstract
me tal materials in engineering applications are subjected to complex cyclic loading environments, making fatigue life prediction critical for ensuring structural safety and reliability. This study aims to develop an efficient and accurate method for predicting the fatigue life of me tal materials and validate its effectiveness through experiments. To achieve this ob jective, the limitations of traditional fatigue life prediction models were first analyzed, leading to the proposal of a multi-scale prediction model that integrates microstructural characteristics with macroscopic mechanical properties. The model incorporates microscale parameters such as dislocation density and grain size as input variables while considering environmental factors like loading frequency and temperature. A systematic investigation of me tal specimens under various operating conditions was conducted using a combination of finite element simulations and experimental tests. The experimental section employed a rotating bending fatigue testing machine to conduct a series of fatigue tests on several typical me tal materials, including low-carbon steel, aluminum alloy, and titanium alloy, yielding extensive stress-life data. Results indicate that the proposed multi-scale model can more accurately describe the fatigue behavior of me tal materials under different conditions, reducing prediction errors by approximately 30% compared to traditional models. Moreover, an in-depth analysis of failure modes revealed a significant correlation between microstructural evolution and macroscopic fatigue damage, providing new insights into material fatigue mechanisms. This research not only enhances the accuracy of fatigue life prediction but also offers theoretical support for optimizing material design and selection, demonstrating important engineering application value.
Keywords：Fatigue Life Prediction Of me tallic Materials; Multi-Scale Model
目 录
摘要 I
Abstract II
一、绪论 1
(一) 金属材料疲劳寿命研究背景与意义 1
(二) 国内外研究现状综述 1
(三) 本文研究方法概述 2
二、疲劳寿命预测理论基础 2
(一) 疲劳损伤基本原理 2
(二) 常用预测模型分析 3
(三) 模型适用性评价 3
三、实验设计与测试方法 4
(一) 实验材料选择 4
(二) 加载方式设计 5
(三) 数据采集与处理 6
四、结果分析与模型验证 6
(一) 实验结果统计 6
(二) 预测模型对比 7
(三) 模型精度评估 8
结 论 10
参考文献 11
金属材料在工程应用中面临着复杂的交变载荷环境，其疲劳寿命预测对于确保结构安全性和可靠性至关重要。本研究旨在建立一种高效准确的金属材料疲劳寿命预测方法，并通过实验验证其有效性。基于此目的，本文首先分析了传统疲劳寿命预测模型的局限性，提出了一种结合微观组织特征与宏观力学性能的多尺度预测模型。该模型引入了位错密度、晶粒尺寸等微观参数作为输入变量，同时考虑了加载频率、温度等环境因素的影响。通过有限元模拟和实验测试相结合的方式，对不同工况下的金属试样进行了系统研究。实验部分采用旋转弯曲疲劳试验机，针对多种典型金属材料（包括低碳钢、铝合金和钛合金）进行了一系列疲劳试验，获得了丰富的应力-寿命数据。结果表明，所提出的多尺度模型能够更准确地描述金属材料在不同条件下的疲劳行为，预测误差较传统模型降低了约30%。此外，通过对失效模式的深入分析，发现微观组织演变与宏观疲劳损伤之间存在显著相关性，为理解材料疲劳机制提供了新的视角。本研究不仅提高了疲劳寿命预测精度，还为优化材料设计和选型提供了理论依据，具有重要的工程应用价值。
关键词：金属材料疲劳寿命预测；多尺度模型；微观组织特征
Abstract
me tal materials in engineering applications are subjected to complex cyclic loading environments, making fatigue life prediction critical for ensuring structural safety and reliability. This study aims to develop an efficient and accurate method for predicting the fatigue life of me tal materials and validate its effectiveness through experiments. To achieve this ob jective, the limitations of traditional fatigue life prediction models were first analyzed, leading to the proposal of a multi-scale prediction model that integrates microstructural characteristics with macroscopic mechanical properties. The model incorporates microscale parameters such as dislocation density and grain size as input variables while considering environmental factors like loading frequency and temperature. A systematic investigation of me tal specimens under various operating conditions was conducted using a combination of finite element simulations and experimental tests. The experimental section employed a rotating bending fatigue testing machine to conduct a series of fatigue tests on several typical me tal materials, including low-carbon steel, aluminum alloy, and titanium alloy, yielding extensive stress-life data. Results indicate that the proposed multi-scale model can more accurately describe the fatigue behavior of me tal materials under different conditions, reducing prediction errors by approximately 30% compared to traditional models. Moreover, an in-depth analysis of failure modes revealed a significant correlation between microstructural evolution and macroscopic fatigue damage, providing new insights into material fatigue mechanisms. This research not only enhances the accuracy of fatigue life prediction but also offers theoretical support for optimizing material design and selection, demonstrating important engineering application value.
Keywords：Fatigue Life Prediction Of me tallic Materials; Multi-Scale Model
目 录
摘要 I
Abstract II
一、绪论 1
(一) 金属材料疲劳寿命研究背景与意义 1
(二) 国内外研究现状综述 1
(三) 本文研究方法概述 2
二、疲劳寿命预测理论基础 2
(一) 疲劳损伤基本原理 2
(二) 常用预测模型分析 3
(三) 模型适用性评价 3
三、实验设计与测试方法 4
(一) 实验材料选择 4
(二) 加载方式设计 5
(三) 数据采集与处理 6
四、结果分析与模型验证 6
(一) 实验结果统计 6
(二) 预测模型对比 7
(三) 模型精度评估 8
结 论 10
参考文献 11
