SOLID-SHELL FINITE ELEMENT MODELS FOR EXPLICIT SIMULATIONS OF CRACK PROPAGATION IN THIN STRUCTURES

摘要

Crack propagation in thin shell structures due to cutting is conveniently simulatedusing explicit finite element approaches, in view of the high nonlinearity of the problem. Solidshellelements are usually preferred for the discretization in the presence of complex materialbehavior and degradation phenomena such as delamination, since they allow for a correctrepresentation of the thickness geometry. However, in solid-shell elements the small thicknessleads to a very high maximum eigenfrequency, which imply very small stable time-steps. A newselective mass scaling technique is proposed to increase the time-step size without affectingaccuracy. New ”directional” cohesive interface elements are used in conjunction with selectivemass scaling to account for the interaction with a sharp blade in cutting processes of thin ductileshells.