航空铝合金应变空间弹塑性本构模型

从应变空间表述的塑性增量本构模型一般形式出发,根据航空铝合金等线性强化材料特性建立应变空间弹塑性本构模型。应变空间本构模型所需参数通过应力空间中对应参数转化得到,材料的屈服准则、流动法则、内变量和塑性模量等准则及参量均以应变空间的形式建立,从而构建适合铝合金等线性强化材料的弹塑性增量模型。通过算例计算,证明该模型与应力空间增量本构模型等效。该模型所需计算变量为可在线获得的应变,使应力分析计算大为简化,可以方便地求解应力空间本构模型难以求解的强化材料变形问题。因此特别适合于航空铝合金厚板预拉伸等金属变形加工工艺的应力分析。

Elasto-plasticity constitutive model for aerospace aluminium alloy in strain space

Based on general form of strain-space incremental plasticity relation,a new model for linear hardening materials was proposed.The model,suitable for isotropic hardening materials like aerospace aluminum alloy,was carried out by determining yield criteria,flow rule,hardening function and plastic modulus in strain space.It is verified that the model was a viable alternative to its stress space counterpart by a test calculation of plane stress.The input variables used in the proposed strain-based model can be measured on-line directly and the calculation of stress is thus significantly simplified concerning difficulty of solving these problems in stress-space.The model is particularly suitable for application of stress analysis in metal processes such as pre-stretch of aluminum alloy plate.