نشریه مهندسی مکانیک و ارتعاشات
سال ششم شماره 1 (پیاپی 18، بهار 1394)

Glass Laminate Aluminum Reinforced Epoxy consist of three or more layers of Al alloy and fibers alternatively. Fatigue crack growth rates in notched fiber-metal laminates under constant amplitude fatigue loading were studied numerically and were compared with them in monolithic 2024-t3 Al alloy plates, it’s shown that the fatigue life of Glare is more longer than monolithic 2024-t3 Al alloy plate and crack growth rate in Glare panel remain constant mostly even when crack is long. stress intensity factor for given crack tip position is determined by a finite element method in ABAQUSE system.

The purpose The purpose of this study is to simulate fluid flow in a weir-type cascade solar still, assuming steady-state and air being the ideal gas and incompressible. The commercial software FLUENT is used for numerical simulation of the process. SIMPLE algorithm is used to calculate the relationship between pressure and velocity. In addition, first order upwind method is applied for separation of displacement and interpolation of pressure. The effective parameters on unit productivity are the distance between glass surface and water, height of solar still, the number of vortexes and convective heat transfer coefficient. Results of investigations on a Solar Still with different height of steps, indicated that the productivity increases with increasing the height of stairs. Although, it should be noted that in each model with specific number of stairs there is an upward-downward trend; in other words, there is an optimum point in each model with specific number of stairs. Also, the still in the specific model of six-stairs with the height of 3.5 cm of stairs had maximum productivity.

In this paper, considering many advantages of distributed generation (DG) and also pay attention to the importance of optimum placement and sizing of these resources in order to reach its advantages, to determination of the optimal location and capacity of DG in distributed generation has been paid. unsuitable location and sizing of DG in distributed networks Leads to disadvantages including Increase losses, voltage profile destruction and reliability of network, stability reduce and harmonic increase. The optimizing that is noticed in this paper offered by presenting a sensitivity factor to reduce of annual energy loss in network and annual costs of DG. It used algorithm method in order to solve optimizing problem and also used IEEE 33-bus radial distributed network as system test. It used 288-h average load model and forward/backward sweep technique to calculate the annual energy loss.

In this article a reliable and efficient switching technique has been proposed to decrease the total harmonic distortion. The total harmonic distortion has harmful effects on electrical devices. Also, leads to increase the temperature in neutral wire of distribution transformers due to over current in power system. The total harmonic distortion has improved by using the proposed technique to eliminate the lower order selection harmonic. Using pulse-width modulation technique is requirement as switching pattern to eliminate the selective harmonic. Therefore, an optimized technique has been proposed to eliminate the lower order selective harmonic for a triple level invertors. The efficiency of the proposed method has been validated and justified through a Simulink in MATLAB software. Also, the proposed technique compared with current pulse-width modulation technique.

The phenomenon of climate change is caused by various factors such as swings at the Earth’s climate, natural processes, and human activities. Following that, the solar absorption has been increasing as compared with the radiation of the Sun’s ray, the Earth is getting warmer, and this change is threatening the lives of the present and also the future generation; all these are caused by the excessive emission of greenhouse gases (GHG) due to the fossil fuel consumption. Since the most important achievements of mankind may be civilization and urbanization and the neighborhood is considered as linchpin of the city frame, firstly, climate change and its factors are described in this paper to relate the aforementioned factors and then the structure of a sustainable neighborhood is examined by defining the concepts of neighborhood and sustainability in order to prevent the continuation of climate change. Achieving the principles and criteria of the neighborhood design requires collaboration of all related specialists, especially architects, urban planners, and the people; then the future generation will be able to meet their own needs and this means sustainable design: future-oriented, environment-oriented, and partnership-oriented.

In the present study, the thermal conductivity of Mg(OH)2-EG nanofluid has been experimentally investigated. All the experiments have been carried out at the temperatures ranging from 24 to 55 °C and different solid concentrations (0.1, 0.2, 0.4, 0.8, 1, 1.5, and 2%). The results declared that the variations of thermal conductivity of Mg(OH)2-EG nanofluid with respect to temperature at the solid volume fractions less than 0.4 %, compared to the higher solid volume fractions, is negligible. Furthermore, the maximum and minimum percentage of increasing the thermal conductivity at solid concentration of 2% is 22% at 55°C and 13% at 24°C, respectively.

In the present paper, the main purpose is determining of the natural frequencies and mode shapes of cover clutch of Peugeot 405. Finally, investigated effect of temperature on the vibration behavior of cover clutch by using ANSYS Workbench software. Thus, obtained first twelve natural frequencies and its mode shapes at room temperature. After that calculated first twelve natural frequencies of cover clutch at different temperatures (maximum 300C) and computed with each other.the maximum word of my abstract is 72 words. please accept it.