粘弹性力学在高温铸造合金单向拉伸试验中的应用

Application of Viscoelasticity Mechanics into Uniaxial Tensile Test of High Temperature Cast Alloy

摘要:

给出了Kelvin链的应力–应变微分型本构关系。全面考虑初始条件，推导了Burgers四参量流体、Kelvin- Maxwell六参量模型在阶跃函数单向应力作用下的总应变通解。Burgers四参量流体、Kelvin-Maxwell六参量模型都可以近似地描述金属材料蠕变曲线的前两个阶段，但都不能反映第三个阶段。铸造Mar-M200合金蠕变曲线的计算表明，两种理论预测与实验测量的结果的一致性较好，特别是Kelvin-Maxwell六参量模型的最大相对误差仅为5.4765779%。 The stress-strain differential constitutive relation was given for Kelvin chain. On basis of all the initial conditions taken into account, the general solutions of total strain were derived for Burgers fluid with 4 parameters and Kelvin-Maxwell model with 6 ones under the step function uniaxial stress. Both Burgers fluid with 4 parameters and Kelvin-Maxwell model with 6 ones could approximately describe the former two stages of creep curve but not reflect the third stage. Numerical calculation for cast Mar-M200 alloy creep curve shows that two theories predictions are in good agreement with test measurement results, especially the maximum relative error of Kelvin-Maxwell model with 6 parameters is only 5.4765779%.