On volumetric locking of low-order solid and solid-shell elements for finite elastoviscoplastic deformations and selective reduced integration

As known from nearly incompressible elasticity, selective reduced integrati on (SRI) is a simple and effective method of overcoming the volumetric lock ing problem in 2D and 3D solid elements. This method of finite elastoviscop lasticity is discussed as are its well-known limitations. In this context, an isochoric-volumetric decoupled material behavior is assumed and thus the additive deviatoric-volumetric decoupling of the consistent algorithmic mo duli tensor is essential By means of several numerical examples, the perfor mance of elements using selective reduced integration is demonstrated and c ompared to the performance of other elements such as the enhanced assumed s train elements. If is shown that a minor modification, with little numerica l effort, leads to rather robust element behaviour. The application of this process to so-called solid-shell elements for thin-walled structures is al so discussed.