<font 20px/inherit;;inherit;;inherit>Large strain viscoelastic-viscoplastic constitutive model applied to 2D contact problems</font>
Motivated by several manufacturing processes, such as cold metal forming and additive manufacturing, we develop a computational code for numerical simulation of two-dimensional problems addressing three types of nonlinearities: geometric nonlinearity, present in large displacements situations; physical non-linearity, present in large strain / inelastic constitutive models; and contact non-linearity.
We present a large strain viscoelastic-viscoplastic model by coupling visco-elastic and visco-plastic models based on the multiplicative decomposition of the deformation gradient. Regarding the 2D application, we consider both plane strain and plane stress hypothesis, where the latter is solved numerically by a local Newton-Raphson procedure. The video above shows the expected behaviour of a viscoelastic-viscoplastic cube under loading-unloading.
For the contact problem, we employ the Node-to-Segment strategy, imposing non-penetration conditions with the introduction of Lagrange multipliers. To show the potentialities of the developed code, several numerical examples are proposed, some of which inspired by existing manufacturing processes. On these examples, we study the effects of different material parameters and strain rates on the numerical response, allowing an analysis of the dissipative behavior due to plasticity and viscosity, including the influence of these on the dynamic damping. Some of these examples are shown in the videos below.
Authors:
Pericles R. P. Carvalho
Rodolfo A. K. Sanches