The expanding ring test of Grady and Benson (1983) is taken as a convenient yet challenging validation problem for assessing the fidelity of cohesive models in situations involving ductile dynamical fracture. Attention has been restricted to 1100-0 aluminum samples. Fracture has been modelled by recourse to an irreversible cohesive law embedded into cohesive elements. The finite element model i...

In this study, cohesive element models are applied to the strength analysis of sandwich structure. As structures have been used increasingly in field automotive light-weighting, becomes an important research topic. Cohesive Zone Models (CZMs) can be predict initiation and propagation material cracks. Therefore, peeling structure is calculated analyzed by traction-separation law with various CZM...

The dynamic delamination in woven glass ®ber reinforced plastic (GRP) composite is studied with a 3D ®nite deformation anisotropic viscoplastic model in conjunction with contact/cohesive laws. The large deformation of the material during impact loading is described through an anisotropic plasticity model in total Lagrangian co-ordinates whose coecients are determined experimentally. The intera...

Damage-induced strain softening is of vital importance for the modeling of localized failure in frictional-cohesive materials. This paper addresses strain localization of damaging solids and the resulting consistent frictional-cohesive crack models. As a supplement to the framework recently established for stress-based continuum material models in rate form (Wu and Cervera 2015, 2016), several ...

Based on the experimental observation of the size effects on the structural behavior of heterogeneous material specimens, the fractal features of the microstructure of such materials is rationally described. Once the fractal geometry of the microstructure is set, we can define the quantities characterizing the failure process of a disordered material (i.e. a fractal medium). These quantities sh...

Bottom-up (constrain-surface) Additive Manufacturing (AM) systems have been widely used in industry. Compared to traditional open-surface AM technology, properties like better vertical resolution, higher material filling rate, less production time, and less material waste make bottom-up AM technology a suitable candidate for fabrication of complex three dimensional materials with high accuracy....

An approximate two-dimensional model for indentation of blunt objects into various types of rigid-perfectly plastic cohesive-frictional material is derived. Particular emphasis is placed on considering indentation as a process involving evolution of the boundary of material displaced by the indenter. Force-penetration relationships are obtained by an incremental approach utilizing key kinematic...

[1] Dry slab avalanches release by propagation of shear fractures in a thin, planar weak layer underneath a cohesive, stronger slab. This implies that a balance between shear fracture toughness and the shear fracture stress intensity factor fundamentally determines snow slab stability. Conventionally, fracture toughness is a material property and, for most materials, emphasis is on tensile frac...

Ballistic impact on composite panels is studied in this work both experimentally and computationally. The purpose was to develop computational methods to analyze a high speed jet engine fragment impacting on composite targets. 12 inch by 12 inch laminated panels with 8, 16, and 32 plies and the standard +-45, 0 /90 degree stacking sequences were considered. With the nominal ply thickness of 0.0...