the problem of several finite moving cracks in a functionally graded material is solved by dislocation technique under the condition of anti-plane deformation. by using the fourier transform the stress fields are obtained for a functionallygraded strip containing a screw dislocation. the stress components reveal the familiar cauchy singularity at thelocation of dislocation. the solution is empl...

abstract: in this paper, the results of experimental and numerical simulation of low velocity impact process have been carried out to investigate energy absorption of composite sandwich panels with 3d woven fabrics of glass fibers and epoxy resin. for this purpose, diagrams of force-displacement of the quasi-static and quasi-dynamic impact tests were studied. for the finite element simulation, ...

Tensile stress-strain curve is of high importance in mechanics of materials particularly in numerical simulations of material deformations. The curve is usually obtained by experiment but is limited by necking phenomenon. Engineering stress-strain curve is converted to true stress-strain curve through simple formulas. The conversion, however, is correct up the point of necking. From this point ...

This study assessed the physical demands of the 24-week Combined Infantryman's Course (CIC) for Parachute Regiment (Para) recruits and developed physical selection standards for applicants. Fifty recruits were monitored over five separate periods (35 d in total during weeks 1-2, 5, 9, 15 and 19-20). Energy expenditure (doubly labelled water), physical activity (accelerometry) and cardiovascular...

A novel composite architecture consisting of a periodic arrangement of closely-spaced spheres of a stiff material embedded in a soft matrix is proposed for extremely high damping and shock absorption capacity. Efficacy of this architecture is demonstrated by compression loading a composite, where multiple steel balls were stacked upon each other in a polydimethylsiloxane (PDMS) matrix, at a low...

UltraSTEEL material has been reported to have higher yield and ultimate strengths than plain mild steel under quasi-static loads. This project aims to study the energy absorption characteristics of UltraSTEEL thin-walled structures when subjected to axial impact loads. The numerical modelling starts from duplicating the UltraSTEEL dimpling process and defining the resultant material properties ...

Ligaments and tendons undergo volume loss when stretched along the primary fiber axis, which is evident by the large, strain-dependent Poisson's ratios measured during quasi-static tensile tests. Continuum constitutive models that have been used to describe ligament material behavior generally assume incompressibility, which does not reflect the volumetric material behavior seen experimentally....

aluminum foams are a novel branch of advanced materials with superior properties. sandwich structures with aluminum foam core are good energy absorbers. in this paper, mechanical properties and energy absorption of aluminum foam sandwich panels subjected to quasi-static perforation tests with conical-nosed indenter were investigated experimentally. for this purpose sandwich panels consisting of...