Contact-impact algorithms are an important component of numerical simulation software in fast transient dynamics.
Traditionally, contact algorithms have been based on so-called sliding lines and sliding surfaces. However, sliding-based
algorithms may present some difficulties in detecting contact in complex geometrical situations, especially in 3D. The
pinball contact-impact method as an alternative formulation has been implemented in EUROPLEXUS, initially based
upon a strong Lagrange-multiplier based solution strategy of the contact constraints.
Recently, at Onera Lille (F) some crash calculations involving many contacts were attempted, initially with linear displacement
continuum elements (CAR4 in 2D). However, to improve accuracy and to help mitigate spurious locking
phenomena, it was desired to perform the same calculations with parabolic elements, namely by the 9-node Lagrange
element Q93.
The present work considers two different approaches to modeling contact with parabolic elements. The first approach
uses a phantom mesh of linear-displacement elements, used only for contact detection, and superposed to the
structural mesh made of parabolic elements. Such a technique is fully general and could be useful also in other special
contact situations, not only with parabolic elements. The second approach is based on a (new) ‘native’ pinball
formulation for the parabolic elements, which has now been developed and implemented in EUROPLEXUS.JRC.G.5-European laboratory for structural assessmen
