# fracture

## cracking analyses in a bended sandwich beam

I'm studying cracking analyses in a three point loaded specimen of a composed beam.I'm using ANSYS and i want to create codes for estimation of J integral and energy release rate in the vicinity of crack tip.After that i'll calculate the stresses and strains fields,and then i can compare the equivalent fields i retrived using CTOD  and K(I,II,III) factors (according to ANSYS algorithm).

My problem is that I'd like to find a relationship between the above mentioned quantities(J,G)  with K(I,II,III)factors.

## Fracture Simulation Using Discrete Lattice Models

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I am trying to implement quasi static fracture in a discrete lattice model, with material being viscoelastic. Do i need to use an incremental-iterative method? Please give your suggestions.

## Refractory

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hello

i am doing M.tech. i wanted to my destertation in improving the strenght of refractory material. so please guide me what is rectent on this topic...

## State-of-the-art understanding of cracking for porous materials?

It seems there are quite a few experimental studies [1,2] on the fracture properties of porous materials, like nanoporous low-k dielectrics, as a function of porosity. Can anyone point out some references on the theoretical part, like the available models, computational methods or analytical approaches that can capture microstructure information, including porosity, pore geometry etc. Interface delamination of porous materials is also of interest. Thanks.

## an interesting puzzle: multiscale mechanics

an interesting puzzle for fun:

Lame’s classical solution for an elastic 2D plate, with a hole of radius a and uniform tensile stress applied at the far field, gives a stress concentration factor (SCF) of two at the edge of the hole. This SCF=2 is independent of the hole radius.

Consider what happened to this concentration factor if the radius a approaches infinitely small. The SCF is independent of a, so it remains equal to two even when the hole disappears.

## The eXtended Finite Element Method (XFEM)

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Hello,

The aim of this writting is to give a brief introduction to the eXtended Finite Element Method (XFEM) and investigation of its practical applications.

Firstly introduced in 1999 by the work of Black and Belytschko, XFEM is a local partition of unity (PUM) enriched finite element method. By local, it means that only a region near the discontinuties such as cracks, holes, material interfaces are enriched. The most important concept in this method is "enrichment" which means that the displacement approximation is enriched (incorporated) by additional problem-specific functions. For example, for crack modelling, the Heaviside function is used to enrich nodes whose support cut by the crack face whereas the near tip asymptotic functions are used to model the crack tip singularity (nodes whose support containes the tip are enriched).