safety and failure in gas pipelines are very important in gas and petroleum industry. for this reason, it is important to study the effect of different parameters in order to reach the maximum safety in design and application. in this paper, a three dimensional finite element analysis is carried out to study the effect of crack length, crack depth, crack position, internal pressure and pipe thi...

A theory of yielding and failure for homogeneous and isotropic materials is given. The theory is calibrated by two independent, measurable properties and from those it predicts possible failure for any given state of stress. It also differentiates between ductile yielding and brittle failure. The explicit ductile-brittle criterion depends not only upon the material specification through the two...

Kevlar is a type of aramid fibers which is characterized by high strength to low weight ratio. This material is widely used in bulletproof vests and helmets, in which it creates a barrier to projectiles to protect specific objectives, laminated tubes and pressure vessels, etc. In this study the ballistic behavior of Kevlar /epoxy composite and Kevlar fabric is investigated. The results showed t...

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 ...

The failure due to accidental drop of magnetic recording disks made of brittle or ductile materials is of great interest in the design of small form factor hard disk drives. In this study, fracture of glass disks (brittle material) and plastic deformation of aluminum disks (ductile material) at very high shock levels caused by accidental drop are investigated using finite element analysis. It i...

We analyze the initiation and propagation of a crack from a point on the surface of a circular notch-tip in an impact loaded prenotched plate. The material of the plate is assumed to exhibit strain hardening, strain-rate hardening, and softening due to the rise in temperature and porosity. The degradation of material parameters due to the evolution of damage in the form of porosity is considere...