Development of methods for damage modeling with enhanced rheological models for the simulation of forming processes

本研究项目涉及工业成形过程中金属材料热-机械耦合行为的建模和仿真。第一个资助期的重点是本构建模方法的发展，考虑到材料损伤的演变。为此，在考虑恢复过程和非弹性变形过程中能量的储存/耗散的情况下，表征热粘塑性材料行为的流变学概念，如先前的研究工作所提出的，已经得到加强，以一致地捕捉热力学损伤过程。此外，基于有限流变网络表示，开发了一种系统的方法，允许在非线性连续介质力学框架下推广大变形单轴流变模型的本构方程。除了材料建模的一些额外方面外，即将到来的第三个项目年将重点放在将带有损伤的本构模型实现到商业有限元程序中，用于运动方程的显式和隐式时间积分，以及参数识别和模型验证，以便进行数值分析和优化热-机械耦合，准静态和动态，复杂的以实践为导向的成形过程。

The research project is concerned with the modeling and simulation of thermomechanically coupled behavior of metallic materials for the application in industrial forming processes. The first funding period has been focused on the development of methods for the constitutive modeling, taking into account the evolution of damage in the material. For this purpose, the rheological concept for representing the thermoviscoplastic material behavior under the consideration of recovery processes and the storage / dissipation of energy during inelastic deformations, as proposed in preceding research works, has been enhanced for capturing thermomechanical consistently the damage processes as well. Moreover, based on a finite rheological network representation, a systematical approach has been developed to allow for the generalization of the constitutive equations of uniaxial rheological models for large deformations in the framework of nonlinear continuum mechanics.Besides some additional aspects of material modeling, the forthcoming third project year concentrates on the implementation of the constitutive model with damage into a commercial FE-programm for the explicit and implicit time integration of the equation of motion, as well as on the parameter identification and the validation of the model, to allow for the numerical analysis and the optimization of thermomechanically coupled, quasi-static and dynamical, complex practice-oriented forming processes.