基于铝合金材料单轴拉伸蠕变实验观测数据,提出了铝合金材料蠕变模型参数优化反演方法。针对3种典型的铝合金材料,分别反演确定了Norton-Bailey和Prandtl-Garofalo蠕变模型中的参数。计算结果表明,蠕变应变与时间的(0.2-0.4)次幂成正比,与等效应力的(6.0-7.6)次幂成正比。对于7050和7B04铝合金材料,Prandtl-Garofalo蠕变模型给出了较高的预测精度。对于7075铝合金材料,Norton-Bailey蠕变模型给出了较高的预测精度。铝合金材料蠕变模型预测的应变与实验值基本一致,验证了所提出模型参数反演方法的有效性。
In order to estimate parameters of creep models of aluminum alloy materials,a parameter inversion procedure is proposed with optimization algorithm,which is based on uniaxial tension creep experiments for aluminum alloy materials.For three kinds of aluminum alloy materials,the parameters of creep models both for Norton-Bailey and Prandtl-Garofalo creep model are determined.The investigation shows that the time exponent (γ+1) in creep model changes from 0.2 to 0.4,and the equivalent stress exponent (β) in creep model changes from 6.0 to 7.6.For 7050 and 7B04 aluminum alloy materials,Prandtl-Garofalo creep model shows higher forecasting precision.For 7075 aluminum alloy material,Norton-Bai-ley creep model shows higher forecasting precision.The forecasting creep strains based on estimated parameters of creep models agree well with observed ones.The effectiveness of proposed parameter estima-ting procedure of creep models of aluminum alloy materials is validated from experimental data.