Composites of concentric cylinders can fail by microcracks that span the thickness and length of one cylinder but arrest at the boundary to adjacent cylinders. This failure mode was analyzed by developing a new polar shear-lag analysis for stresses in a cross section of a concentric-cylinder composite. The analysis can accurately calculate stresses in each cylinder in the presence of microcrack...

Nowadays biodiesel is receiving more attention as a most important renewable energy for using in diesel engines. Inthis research, the application of Response Surface Methodology (RSM) was highlighted to investigate the effects of biodiesel-diesel blends (B0, B20, B50 and B100), engine operating parameters (engine load and  speed) on CO2 emission of a diesel engine. The experiments were conducte...

This research seeks to evaluate damage on the fuel tank by an acoustic emission test when executing 20000 cycles fatigue test and thereafter burst test. Used gas cylinders in the experimental are three types as follows; one is sound cylinder, others are cylinders which contain longitudinal and transverse artificial defect. The size of artificial defect is a depth of 3 mm, width of 3 mm and leng...

In this work, the stress distribution along cylindrical composite pressure vessels with different dome geometries is investigated. The contours are generated through an integral method based on shell stresses. Here, influence of each contour at interface dome-cylinder evaluated. At first, formulation for curve generation presented and solved contours. An analytical approach calculation secondar...

The fracture behavior of a composite cylinder subjected to a moving pressure has been investigated. The resonance of stress waves can result in very high amplitude of strains in the cylinder at the instant and location of pressure front passage when the velocity of the moving pressure approaches a critical velocity. The stress wave with high magnitude, while short in duration, might not cause s...

In this paper, numerical simulation of FRP composite cylinder tubes progressive crushing processes is conducted using LS-Dyna. Details on the numerical modeling strategy are given and discussed. It is found that triggers introduced in the numerical simulation can effectively model the bevel trigger at the end of the tubular specimens. It is also found that two-layer finite element model based o...

in the current paper, finite element method is employed for numerical simulations and the study of influential parameters on elastic modulus of polymer-matrix nano-composites. effects of different key parameters including particle elastic modulus, interphase elastic modulus, matrix elastic modulus, interphase thickness and particle volume fraction on total elastic modulus of nano-composite mate...

This in vitro study analyzed the effect of different load application devices on fracture resistance and failure mode of maxillary premolars restored with composite resin. Sixty human maxillary premolars received standardized mesio-occluso-distal cavity preparations and were restored with composite resin. The specimens were randomly divided into 6 groups (n=10). Compressive loading was applied ...