采用Gleeble-3500热模拟机测试了6013铝合金在613773 K、0.00110 s-1下的平面应变流变力学行为,并基于变形温升修正了试验测量的流变应力数据。选取Kriging方法对该热变形过程本构关系进行建模,并通过统计学分析、对比分析和舍一交叉验证法对所建模型的预测能力与可靠性进行评价。结果表明:构建的Kriging模型预测精度较高,其预测值与实验值对比得到的R值为0.999、AARE值为0.478%,相较于修正的Arrhenius-type模型具有显著优势。通过基于舍一交叉验证法设计的25次测试与验证,充分说明了Kriging模型具有较好的泛化能力。由此可知,通过Kriging方法可高效构建精确模型以描述合金热变形流变行为并有效预测试验条件范围以外的流变应力。
Hot plane strain compression tests of 6013 aluminum alloy were conducted within the temperature range of 613?773 K and the strain rate range of 0.001?10 s?1. Based on the corrected experimental data with temperature compensation, Kriging method is selected to model the constitutive relationship among flow stress, temperature, strain rate and strain. The predictability and reliability of the constructed Kriging model are evaluated by statistical measures, comparative analysis and leave-one-out cross-validation (LOO-CV). The accuracy of Kriging model is validated by the R-value of 0.999 and the AARE of 0.478%. Meanwhile, its superiority has been demonstrated while comparing with the improved Arrhenius-type model. Furthermore, the generalization capability of Kriging model is identified by LOO-CV with 25 times of testing. It is indicated that Kriging method is competent to develop accurate model for describing the hot deformation behavior and predicting the flow stress even beyond the experimental conditions in hot compression tests.