Dynamic fracture mechanics and energy distribution rate response characteristics of coal containing bedding structure

FRACTURE MECHANICS WHAT IS FRACTURE MECHANICS Fracture mechanics is mechanics of solids containing planes of displacement discontinuities (cracks)

Experimental study of fracture mechanics in the aluminum matrix composites containing Fifteen percent silicon carbide particles

In this investigation ‚the fracture toughness of A356 containing15%SiC composite was studied. Al/SiC composites have been considered because of their mechanical and erosion properties .Low fracture toughness in Al/SiC as compared with Aluminium alloys is one of its disadvantage. In this study at first A356 alloy was melted in a smelting electrical furnace then poured into the mould. A356-15% Si...

Energy Management in Microgrids Containing Electric Vehicles and Renewable ‎Energy Sources Considering Demand Response

Microgrid and smart electrical grids are among the new concepts in power systems that support new technologies within themselves. Electric cars are some advanced technologies that their optimized use can increase grid efficiency. The modern electric cars sometimes, through the necessary infrastructure and proper management, can serve as an energy source to supply grid loads. This study was cond...

0 Ju n 20 08 Shape derivative of potential energy and energy release rate in fracture mechanics

We study general mathematical framework for variation of potential energy with respect to domain deformation. It enables rigorous derivation of the integral formulas for the energy release rate in crack problems. Applying a technique of the shape sensitivity analysis, we formulate the shape derivative of potential energy as a variational problem with a parameter. Key tools of our abstract theor...

the underlying structure of language proficiency and the proficiency level

هدف از انجام این تخقیق بررسی رابطه احتمالی بین سطح مهارت زبان خارجی (foreign language proficiency) و ساختار مهارت زبان خارجی بود. تعداد 314 زبان آموز مونث و مذکر که عمدتا دانشجویان رشته های زبان انگلیسی در سطوح کارشناسی و کارشناسی ارشد بودند در این تحقیق شرکت کردند. از لحاظ سطح مهارت زبان خارجی شرکت کنندگان بسیار با هم متفاوت بودند، (75 نفر سطح پیشرفته، 113 نفر سطح متوسط، 126 سطح مقدماتی). کلا ...