Simple derivation of the dual conservation integrals in small strain elasticity is presented, without the aid of Noether’s theorem on invariant variational principles. The derived integrals are related to the release rates of the potential and complementary potential energy associated with the defect motion. The analysis corrects the errors in earlier derivation of the relationship between the ...

In this paper, an approach to aeronautical structural design based on reliability analysis is presented. In this way, the concept of level of safety is discussed and methods of its calculation using statistical data are described. Based on the concept of level of safety, a design procedure is proposed. In order to validate this design procedure, two design cases are studied. In the first case s...

Seventy-two crossbred (Large White X Landrace) pigs were used in a 3 X 7 factorial experiment to investigate the response of two strains of boars (strains A and B) and of castrated male pigs (strain B) to seven levels of intake of a single diet (ranging from 5.3 Mcal digestible energy [DE]/d to ad libitum) between 45 and 90 kg live weight. All aspects of growth performance and body composition ...

High-strength low alloy steels (HSLA) have been designed to replace high-yield (HY) strength steels in naval applications involving impact loading as the latter, which contain more carbon, require complicated welding processes. The critical role of HSLA-100 steel requires achieving an accurate understanding of its behavior under dynamic loading. Accordingly, in this paper, we experimentally inv...

The strain rate effect of luffa sponge material is an indispensable property for it to be used for acoustic, vibration, and impact energy absorption. Compressive tests at different strain rates on cylindrical column specimens of luffa sponge material were conducted over a wide density ranging from 24 to 64 kg/m. A photographic technique was applied to measure the section area of the specimen wi...

The fracture mechanics of electromechanical materials has been investigated for well over a decade, yet there still exists controversy over the appropriate crack face boundary conditions for non-conducting cracks. In this paper an experimental protocol for measuring the energy release rate in a non-linear reversible electromechanical body is proposed and summarized. The potential results from t...

We consider the quasi-static evolution of a straight crack within the recent phase field approach and the classical sharp crack approach. We show a strong correlation between the two approaches: energy, minimizers, energy release rate and quasi-static evolutions converge as the internal length parameter of the phase-field approach tends to zero. A crucial point in the proof is a novel represent...

background petroleum hydrocarbons are mix compounds and divided into four groups: saturates, aromatics, resins and asphalten. among various phases of crude-oil, the alkanes with medium length chain are favorable substrates that rapidly degraded, although short-chain alkanes are very toxic and long-chain alkanes have low solubility in water that reduce its bioavailability and make resistant to b...

it is possible to alter the permeability of ethyl cellulose membrane with certain materials such as surfactants. in this study the effect of surfactant concentration and different hlb values on the release rate of atenolol from ethyl cellulose-coated tablets was evaluated. the results showed that when the concentration of surfactant increased, the rate of drug release also increased. the kineti...

Energy is an internal variable during rock deformation and failure, its dissipation conversion law can reflect the rock’s damage deterioration state. Analysis of failure process from perspective energy helpful to deeply understand mechanism damage, fracture instability has important theoretical practical significance for stability evaluation support control surrounding rock. In this study, thro...