This paper deals with the development of a numerical simulation methodology for estimating damages in laminate composite materials caused by a low-speed impact. Experimental tests were performed on laminate plates reinforced with woven carbon fibers and epoxy resin. Three thickness plates were evaluated. The impact loads were transversal and punctual. Two lamina failure criteria were evaluated....

there are various parameters that affect stability and expansion of failure zones in under pressure tunnels. among the important parameters that affect failure zones around the tunnels are cohesion and internal friction angle of the rock mass. in addition, the cross sectional shape is the considerable point in failure distribution around the tunnels. the stress analysis method is one of the app...

introduction: the clinical and paraclinical characteristics of patients with congestive heart failure (chf) have been described by a number of previous studies, but very little information is available on this issue in iran. this study aimed to delineate the clinical and paraclinical characteristics of iranian patients hospitalized with chf. methods: during an observational, analytical, descrip...

Seismic safety of liquid storage tanks is of considerable importance due to its application in different industries. In Iran, most of these storage tanks are designed based on API650 code provisions. Despite designing tanks according to API standard, the lesson learned from previous earthquakes, shows different kind of damage occurring on them. This study is an investigation on evaluating diffe...

The existing failure criteria to evaluate discontinuous rocks are predominatly based on the relations between principal stresses at failure. None of the criteria has a direct reference to the magnitude of deformation as a major parameter in rock Several reasons are identified indicating that the selection of peak stress as a major parameter, which is obtained through the evaluation of a failure...

A new failure criterion was presented to predict the ultimate strength of shale under the triaxial and polyaxial state of stress. A database containing 93 datasets was obtained from the results of the uniaxial, triaxial, polyaxial compressive tests, an indirect tensile test was collected from reliable references, and this test was carried out on the shale samples taken from the southwestern oil...