【摘要】 回顾了航空发动机涡轮盘粉末高温合金材料的发展及研究方法,基于Cosserat连续体理论,建立了粉末高温合金材料的弹塑性损伤模型,可通过特征长度考虑材料的微结构特征,并在模拟软化问题时消除局部化带的网格依赖性.在软化问题中,经典弹塑性理论在计算时需要较多迭代,有时甚至不能收敛.该文基于参变量变分原理,把原非线性问题转化为互补问题来求解,可大大提高求解效率和收敛性.最后通过数值算例验证了本文提出方法的有效性.更多还原

【Abstract】 The development of the powder metallurgy( PM) superalloy applied in turbine discs of high thrust-weight ratio aeroengines was reviewed. Based on the Cosserat continuum theory,the elastoplastic damage model for the PM superalloy was developed in which the microscopic properties were modeled with the characteristic lengths of the material. Furthermore,the mesh dependency of the localized bands in the analysis of softening problems was eliminated in the present model. For the softening problems,massive iterations were usually needed with the classical elastoplastic methods and may not converge in some cases. Based on the parametric variational principle,the original nonlinear problem was transferred to a complementary problem,then the efficiency and convergence of the solution were greatly improved.Finally,several numerical examples demonstrate the validity of the proposed method.更多还原