Speaker
Description
Explicit finite element solvers are commonly used for the simulation of sophisticated industrial processes. These methods are particularly beneficial in scenarios characterised by high strain rates, complex contact interactions, or rapid failure processes, making them indispensable for simulating manufacturing operations such as forming processes or impact loading. To capture the localisation and evolution of damage and to obtain mesh objective solutions, the incorporation of regularisation approaches is essential, with gradient-enhancement emerging as one of the most promising options. However, classic micromorphic formulations of gradient-enhanced damage models, as discussed in e.g. [1], result in elliptic partial differential equations, which are inherently incompatible with explicit solver frameworks. To address this incompatibility, a reformulation of the field equation into a hyperbolic structure was proposed in [2].In view of these developments, this contribution presents a comprehensive discussion of such dynamic micromorphic formulations. A dimensional analysis is performed to establish the scaling characteristics. The regularisation properties are explored based on wave propagation analyses. An implementation into an explicit finite element solver is presented, with particular attention dedicated to the stability of the time integration scheme. Representative boundary value problems are presented to validate the formulation and to demonstrate its potential for practical applications in process simulations.
[1] Forest S. (2009) Micromorphic approach for gradient elasticity, viscoplasticity, and damage. Journal of Engineering Mechanics 135(3) 117-131.
https://doi.org/10.1061/(ASCE)0733-9399(2009)135:3(117).
[2] Saanouni K., Hamed M. (2013) Micromorphic approach for finite gradient-elastoplasticity fully coupled with ductile damage: Formulation and computational aspects. International Journal of Solids and Structures 50(14) 2289-2309.
http://dx.doi.org/10.1016/j.ijsolstr.2013.03.027.
