Mass and velocity scaling in the simulation of deep drawing processes using explicit solvers
Sprache des Vortragstitels:
European Conference on Aluminium Alloys 2011
Sprache des Tagungstitel:
Mass and velocity scaling are widely used methods to reduce the computational effort in the simulation of quasi-stationary processes such as deep drawing of metal blanks. Because of of their advantages in numerical stability, the usage of explicit dynamic solvers is state of the art for simulation of metal forming processes. Hereby scaling methods aim to reduce the number of calculation steps in order to reduce the computation time. The mass scaling method increases the critical time step by scaling the density and reducing the sound propagation speed of the material. Using the velocity scaling method, the speed of the deep drawing punch is increased; the same punch displacement is reached at an earlier point in time and the number of calculation steps is again reduced. Although mass scaling and velocity scaling are often applied simultaneously, it will be shown, that this is not necessary since both methods rely on the same theoretical background. In this presentation both scaling methods and their theoretical background are presented and the effects of their usage are discussed on the simple mechanical model of a spring-damper-mass-system. The conclusions drawn from this model are then applied to a deep drawing process simulation using Abaqus/Explicit. In the simple model as well as in the numerical simulation, it is shown that mass and velocity scaling are essentially equivalent methods, which yield nearly identical simulation results (including the error made by the dynamic calculation of a quasi-stationary process) with the same computational effort.