In this contribution an overview over a numerical scheme for the crack modelling of spruce wood under tensile loading is given. A material model for biaxially stressed spruce wood with consideration of the effect of knots on the strength properties has been developed. A necessary feature of this material model is its ability to treat cracks by means of the so-called smeared crack concept. For t...

Final failure of laminated composite structures is preceded by different damage mechanisms involving fracture initiation and propagation. Fracture in a composite laminate can appear either between two plies or within a lamina. In the first case, interlaminar fracture or delamination, the crack causes separation of two adjacent plies and will mainly involve matrix failure or matrix-to-fibre debo...

Composite material is a combination of two or more materials on a macroscopic scale to form a useful material. Composite find tremendous application in marine, automobile, sports & recreation equipments etc. Hence a quantum of research is going on in order to find the improvements in existing combination of composites. One of the most promising composite in the current scenario is Carbon Fabric...

Computer simulation of fracture processes remains a challenge for many industrial modelling problems. In a classical finite element method, the non-smooth displacement near the crack tip is captured by refining the mesh locally. The number of degrees of freedom may drastically increase, especially in three dimensional applications. Moreover, the incremental computation of a crack growth needs f...

The fracture behaviour of human cortical bone was analysed considering a miniaturized version of the Double Cantilever Beam (DCB) test. A specific data reduction scheme based on crack equivalent concept was used to obtain the resistance curves. The definition of the cohesive laws mimicking the fracture process was performed measuring the crack tip opening displacement by digital image correlati...

Crack-tip behaviour in metals is among the most basic problems in mechanics of materials. Yet, long-standing experimental evidence suggests that crack-tip twinning in face-centred-cubic (f.c.c.) metals is highly dependent on the material, temperature and loading rate, and previous simulations and models predict twinning in aluminium, where it has never been observed. Here, this discrepancy betw...

Crack initiation and growth behaviour of an austempered ductile iron (ADI) austenitised at 800C and austempered at 260C has been assessed under three point bend fatigue conditions. Initiation sites have been identified as carbides remaining from the as cast ductile iron due to insufficient austenisation. The number of carbides cracking on loading to stresses greater than 275 MPa is critical in ...

We consider a quasistatic system involving a Volterra kernel modelling an hereditarilyelastic aging body. We are concerned with the behavior of displacement and stress fields in the neighborhood of cracks. In this paper, we investigate the case of a straight crack in a two-dimensional domain with a possibly anisotropic material law. We study the asymptotics of the time dependent solution near t...

A two-dimensional numerical model of microstructural e ects in brittle fracture is presented, with an aim towards the understanding of toughening mechanisms in polycrystalline materials such as ceramics. Quasi-static crack propagation is modelled using the extended nite element method (X-FEM) and microstructures are simulated within the framework of the Potts model for grain growth. In the X-FE...

A concurrent multi-scale computational strategy for rail surface crack initiation analysis is introduced in current paper. It attempts to take advantage of the efficiency of macroscopic models and the accuracy of the mesoscopic models. The solving procedure is , through the coupling of individual approaches, beginning from the largest scale to the smaller scale, making use of multi-body dynamic...