灰色预测模型在压载疲劳寿命预测中的应用

Application of Grey Prediction Model in Fatigue Life Prediction under Compressive Stress

针对关于压载的疲劳试验难以实现和数据较少,以及现有的估寿公式能否用于单调压载疲劳寿命分析的不确定性等问题,引入了灰色关联度分析,并建立多维灰色系统预测模型。利用7075-T651铝合金压载疲劳试验数据,对预测模型的准确性进行了评估,拟合结果相对误差小于6%,表明了该模型的有效性。最后利用该模型对7075-T651铝合金的压载疲劳寿命进行了预测,预测结果与试验结果相对误差小于10%。结果表明模拟结果与试验结果吻合良好,具有很好的工程实用价值。

In order to solve the problem that the fatigue test of compression is difficult to realize and the data is few,and the uncertainly of whether the existing formulas for life prediction can be used for the fatigue life analysis under compressive loadings,the grey correlation analysis is introduced and the multi-dimensional grey system prediction model is established in this paper.The test data of 7075-T651 aluminum alloy under compressive stress is used to evaluate the accuracy of the prediction model and the relative error of the fitting result is less than 6%,indicating the effectiveness of the model.Finally,the model is used to predict the fatigue life of 7075-T651 aluminum alloy under compressive stress,and the relative error between the prediction result and the test result is less than 10%.The results show that the simulation results are in good agreement with the experimental results and have good practical value in engineering.