The work described herein consists of experimental measurement of the post-impact buckling loads of Eglass/epoxy laminates. Composite samples with stacking sequence of [+45/45/90/0]2s were subjected to low-velocity impact loading at energy levels of 36, 56.13, 79.95, 110.31 and 144 J. The impact tests were conducted with a specially developed vertical drop weight testing machine. Impact parame...

In this paper, the buckling of carbon nanotubes, modeled as nonlocal one dimensional continua within the framework of Euler–Bernoulli beams, is considered. Both a stress gradient and a strain gradient approach are considered and a variational approach is adopted to obtain the variationally consistent boundary conditions. The dependence of the buckling load on the nonlocal parameter has been det...

the plate girders are used in important structural systems. the earlier design of plate girders was restricted to their critical bukling capacity. experimental and theoretical studies show the plate girders with vertical stiffners can carry load over than their critical buckling loads and then in modern design codes is permitted to use post- buckling capacity of them. in this case the out- of- ...

cylindrical thin-walled tubes due to construction and easy installation, high energy absorption capacity are used in the automotive industry as an impact energy absorber. however, the main weakness of cylindrical tubes is in the high initial peak load. therefore, in this paper, to overcome this weakness, a buckling initiator is used at the top of the tube. this buckling initiator is a steel rod...

composite concrete-steel plate shear walls are the most critical resisting structural members that resist lateral and axial loads. This type of wall consisting of two steel faceplates presenting the outer skin, infill concrete and shear connectors which are used to provide the composite action of the steel faceplates with infill concrete in order to increase the strength and to reduce the local...

This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the “plane-strain” core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions aro...

In this paper, simulation and analysis of thin steel cylindrical shells with elliptical cutouts under oblique loading were studied using finite element method. First, the numerical results were validated by the results of experimental test performed by an INSTRON 8802 servo hydraulic machine. Also, the effect of cutout angle (θ), cutout size, cutout position (L0/L) and cutout aspect ratios (b/a...

understanding how a cutout influences the load bearing capacity and buckling behavior of cylindrical shells is fundamental in the design of structural components used in automobiles, aircrafts, and marine structures. in this article, simulation and analysis of steel cylindrical shells with various lengths, include quasi elliptical cutout, subjected to axial compression were systematically carri...

The influences of curvatures and of physical properties on the mechanical stability of the spine were analysed by means of a three-dimensional, geometrical, nonlinear biomechanical model. According to the model, the initial buckling load decreases with increasing lordotic and kyphotic curvatures. When the body weight is taken into account as a load distributed along the whole spine, the calcula...

abstract: the present study deals with the buckling analysis of the laminated composite truncated conical sandwich shells with flexible core subjected to combined axial compressive load and external pressure. higher order governing equations of the motion are presented for conical composite sandwich shells, where they are derived from the hamilton principle. then, by the use of improved higher-...