基于有限元法和锁相热像法对含缺陷构件的应力分析与疲劳性能评估

基于有限元法研究含盲孔缺陷构件的应力集中系数Kt随盲孔深度h和盲孔直径的变化规律。利用锁相热像法的热弹性分析模式(E-Mode)研究盲孔附近的应力分布,预测不同深度盲孔的Kt,与有限元结果相比较发现吻合良好。通过Altair Li软件中的耗散模式(D-Mode)和Altair软件分别研究构件在疲劳过程中的固有耗散量和温度信号的变化规律,以评估疲劳损伤的演化过程。以固有耗散和温度信号的变化规律作为疲劳损伤的指标,快速预测带盲孔试件的疲劳极限,进而预测试件的疲劳缺口系数Kf。理论计算的结果证明了锁相热像法的有效性。

Stress Analysis and Fatigue Behavior Assessment of Components with Defect Based on FEM and Lock-in Thermography

The relationships between the stress concentration factor Kt with the depth h and diameterφof the blind hole were investigated based on the FEM .The thermo‐elastic analysis mode (E‐Mode) built‐in the lock‐in thermography was utilized to study the stress distribution around the blind hole , and to predict the variation of Kt of different depth .Good predictions were achieved between the ther‐mography and FEM .The variations of the intrinsic dissipation and the temperature signal during fa‐tigue process were studied respectively using the dissipation mode (D‐Mode) of Altair Li and Altair software ,to evaluate fatigue damage evolution .These two signals were considered as fatigue damage markers to rapidly predict the fatigue limit and the fatigue notch factor Kf of the component with blind hole .T he theoretical result validates the capability of the lock‐in thermography .