جستجوی مقالات مرتبط با کلیدواژه « Temperature Variation » در نشریات گروه « عمران »

One of the most effective factors regarding the design of airfield concrete pavements is its performance relative to the temperature and static load caused by airplane traffic. This research aims at evaluation of tensions and deformations occurring in concrete slabs at the airfield concrete pavements, arising from temperature variations and the layout of the aircraft wheels design (Airbus 320), in the 3D model and in the SAFE software environment. By analyzing models and outcomes, it is observed that tensions and displacements and deformations created in the slabs under load caused by the temperature, are much higher than the wheel load. Furthermore, by increasing the thickness of the slabs and their dimensions, the stresses caused by the temperature are increased while the stresses caused by the wheels are decreased.

Large dams store a significant amount of water behind them. Therefore, their safety and stability control have a special place. Changes in temperature and hydrostatic pressure are the most important factors that affect the dam structure; And will cause shifts in the crown of the dam upstream and downstream. Therefore, the data obtained from the monitoring center should be evaluated regularly in order to analyze the behavior of the dam. Due to this issue, in this study, using artificial neural networks, a model is presented to predict the horizontal displacement of the Dez dam crown due to changes in pressure and temperature. According to the results, it is observed that the neural network has a good performance in predicting real values. The average error of the modeled network is about 4%. This indicates that the network is well trained. Using the generated network, the radial displacement changes against the reservoir water level for different temperatures are obtained, and plotted. Using diagrams, it is possible to predict the behavior of Dez dam for different temperatures and changes in reservoir water level, which can be very useful in monitoring and maintaining this dam.

The accurate understanding of the behavior and analysis of the structures is necessary to appropriate design of them. Over the past decades, various methods have been proposed for the analysis of structures that each of them include some deficiencies. The peridynamic is a new method for solving the problems. This method overcomes the deficiencies and limitations of conventional methods such as the finite element method due to its unique capabilities. Nowadays, it uses as a powerful method to solve problems. After the proposition of peridynamic theory in 2000, various problems have been solved. However, very limited work has been done in the solving longitudinal vibration of axial members and modeling of lattice structures. In this paper, the behavior of this type of members was examined by the peridynamics method and its capability to take into account the static and dynamic loading, as well as temperature variations, was shown using MATLAB software. The peridynamic results are in good agreement with analytical results. Also, for certain states of the problem, it is impossible or difficult to find an answer by analytical methods or other methods, while using the peridynamic method can easily be answered. Finally, the peridynamic model has been extended to truss modeling and the ability of this method to analyze any types of trusses were shown.

Slab made of concrete pavement under the load deformation and deformation caused them cracks to the section.in this study the size and thickness of the concrete slab(JRCP) under the Temperature loading and aircraft B777-300in the amount and location and width of cracks were studied to determine the effect of it. The research field studies and library and using design software slab (safe) an analysis model is designed. The results show that by increasing the slab thickness and dimension, the width of the cracks under loads caused by the temperature difference is further reduced in size suggests continuity between the slap is low caused cracks and the increase of leave and the creation of critical that more is. The load carried by the wheel at the edge of the slab and the width of the cracks is more of a load in the middle of the slab and the cracks made linearly. By study the cracks on the slab with variable dimensions and load type shows that the with variable dimensions and load type shows that the width of cracks on the underside of the slab surface is greater than the surface .on the formation of cracks in the wheel load at the section of the slab. Leaving detailed in the center of the surface and spread it around in place of slab surface cracks around the back wheel and the radial shape is formed.