The elastic-plastic fracture toughness JIc tests by the stretched zone method were performed to obtain JIc values for machine structural steels. The validity of the JIc values obtained was evaluated, and the effects of the heat treatment conditions and microstructure of steels on the JIc values were investigated by use of streched zone width, SZW. The results obtained are summarized as follows....

Based on Rayleigh beam theory, the sub-impacts of a free-free beam struck horizontally by a round-nosed rigid mass is simulated by the finite difference method and the impact-separation conditions. In order to obtain the sub-impact force, a uniaxial compression elastic-plastic contact model is employed to analyze the local deformation field on contact zone. It is found that the horizontal impac...

Glass fiber reinforced plastic composite materials are finding increased applications due to their excellent properties. Fiber reinforced plastic (FRP) composite materials comprise soft matrix and fiber elements. This article presents the tribological aspects of glass fiber reinforced plastic composites. The wear test is carried out for FRP in a pin-on-roller wear tester. The wear rate obtained...

A general method for the derivation of velocity ®elds consistent with the basic kinematics of the trishear model of faultpropagation folding is given. We show that the ®elds can be written as explicit functions of position within the deformation zone. To demonstrate the approach, several di€erent linear and non-linear velocity ®elds are derived and plotted. We show that the trishear zone need n...

315 than where total inhibition zones had formed. The important observation to make is that, outside of the inhibition zone, the inoculated cells multiplied to form visible colonies despite being in the triclosan vapour for up to 72 h at 22°C. This is entirely in accord with zone theory and, of course, everyday experience with diffusion susceptibility tests. It is unlikely therefore that at amb...

The different shot peening responds of a grey cast iron (GI) with its flake graphite and a compacted cast iron (CGI) with its vermicular graphite was analyzed and compared in this paper. For peening using identical parameters, CGI showed a larger plastic deformation zone with higher subsurface compressive stresses than GI. Electron backscatter diffraction (EBSD) mapping and backscatter electron...

Non-linear quasi-static axisymmetric indentation problem is studied for comparitive computational analysis between elasto-plastic parameters and mechanical behaviour of homogeneous engineering metal materials. Mathematical model, based on deformation theory version of J2 theory, leads to quasi-static elasto-plastic contact problem with unknown contact domain, depending on the value of a indenta...

The existence of a finite threshold, the yield stress, for the onset of plastic yielding is a universal feature of plasticity. This jamming-unjamming transition is naturally accounted for by the dynamics of a bistable internal state field. We show, within the athermal shear transformation zone theory of amorphous plasticity, that the transition is accompanied by the propagation of plastic front...

Friction stir processing (FSP) has been developed on the principles of friction stir welding (FSW) as an effective and efficien new method for grain refinement and microstructural modification, providing intense plastic deformation as well as higher strain rates than other conventional severe plastic deformation methods. FSP produces an equiaxed homogeneous microstructure consisting of fine gra...