• delaminations
• explicit
• impacts

Delaminations in composite material structures are a dangerous problem because of their difficult detectability and of the reduction in strength that they can cause. This problem is particularly perceived in the Aerospace industry. Efficient numerical modelling of delaminations could help predicting structures behavior, reducing the need for experimental testing and thus reducing costs.
For this reason the aim of this work is to gain significant knowledge on a new modelling technique for the simulation of delaminations. The interlaminar behavior is simulated using special purpose elements, the cohesive elements, in Abaqus/Explicit. The constitutive law of these elements is provided by means of a user-written Fortran subroutine, called VUMAT. Through the simulation of increasingly complex models and the comparison with consolidated modelling techniques, accuracy, in terms of forces and delaminated areas, are assessed. It is shown that the new technique is able to well predict delamination onset and propagation, even for complex events, such as low velocity impacts. Anyway Abaqus/Implicit remains to be preferred in terms of results accuracy.