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Crack propagation and buckling interaction: The case of tube splitting

ALI LIMAM (INSA Lyon), DINH CUONG TRAN (INSA Lyon)

Instability in Solids and Structures

Mon 9:00 - 10:30

Barus-Holley 190

The development of energy absorbers by “tearing” or “splitting” circular tubes enabled us to observe that in certain cases a wrinkling of the free edges or crack lips appeared behind the crack tip. These undulations of buckling have a wave length which depends on the geometrical characteristics of the tube and on the velocity at which the tear propagates. In order to understand the origins of this phenomenon associated to the buckling of “free edges”, several experiments are conducted for various geometries of stainless steel tubes (R/t, L/R) and for various sizes of the initial defect (crack length). Numerical modelling with Abaqus code couples several nonlinearities, like large displacements necessary to the buckling analysis, plasticity in order to reproduce the ductile tearing and surface contacts associated to specific boundary conditions. Simulation using solid elements or solid shell element, as well as a specific cohesive element developed for this study to manage the crack propagation, enabled us to corroborate the experimental observations.