Journal of Applied and Computational Mechanics
Volume:4 Issue: 1, Winter 2018

The present study investigates the buckling of a thick sandwich plate under the biaxial non-uniform compression using the modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for the central core the isotropic soft materials are investigated. The simplified first order shear deformation theory (S-FSDT) is employed and the governing differential equations are obtained using the Hamilton’s principle by considering the Von-Karman’s nonlinear strains. An analytical approach is applied to obtain exact results with different boundary conditions. Due to the fact that there is no research on the stability of micro/nano sandwich plates based on S-FSDT including the couple stress effect, the obtained results are compared with the FSDT studies which use the Eringen nonlocal elasticity.

Bending, buckling and vibration behaviors of nonlocal Timoshenko beams are investigated in this research using a variational approach. At first, the governing equations of the nonlocal Timoshenko beams are obtained, and then the weak form of these equations is outlined in this paper. The Ritz technique is selected to investigate the behavior of nonlocal beams with arbitrary boundary conditions along them. To find the equilibrium equations of bending, buckling, and vibration of these structures, an analytical procedure is followed. In order to verify the proposed formulation, the results for the nonlocal Timoshenko beams with four classical boundary conditions are computed and compared wherever possible. Since the Ritz technique can efficiently model the nano-sized structures with arbitrary boundary conditions, two types of beams with general boundary conditions are selected, and new results are obtained.

This paper is an attempt to determine quasi-static thermal stresses in a thin elliptical plate which is subjected to transient temperature on the top face with zero temperature on the lower face and the homogeneous boundary condition of the third kind on the fixed elliptical curved surface. The solution to conductivity equation is elucidated by employing a classical method. The solution of stress components is achieved by using Goodier’s and Airy’s potential function involving the Mathieu and modified functions and their derivatives. The obtained numerical results are accurate enough for practical purposes, better understanding of the underlying elliptic object, and better estimates of the thermal effect on the thermoelastic problem. The conclusions emphasize the importance of better understanding of the underlying elliptic structure, improved understanding of its relationship to circular object profile, and better estimates of the thermal effect on the thermoelastic problem.

In this paper, buckling and free vibration analysis of a circular tapered nanoplate subjected to in-plane forces were studied. The linear variation of the plate thickness was considered in radial direction. Nonlocal elasticity theory was employed to capture size-dependent effects. The Raleigh-Ritz method and differential transform method were utilized to obtain the frequency equations for simply supported and clamped boundary conditions. To verify the accuracy of the Ritz method, the differential transform method (DTM) was also used to drive the size-dependent natural frequencies of circular nanoplates. Both methods reported good results. The validity of solutions was performed by comparing the present results with those of the literature for both classical plate and nanoplate. The effects of nonlocal parameter, mode number, and taper parameter on the natural frequency were investigated. The results showed that increasing the taper parameter causes increasing of buckling load and natural frequencies, and its effects on the clamped boundary condition is more than the simply support.

The main objective of this study is to reduce the retrieval time of a list of products by choosing the best combination of storage and retrieval rules at any time. This is why we start by implementing some storage rules in an Automated Storage/Retrieval System (Automated Storage and Retrieval System: AS/RS) fitted with a gravity conveyor while some of these rules are dedicated to storage and others to retrieval. The system is seen as a Multi-Agent System (MAS) where the produced agents are reactive agents that can interact to achieve a behavior (organizing the store). Our MAS is characterized by a decentralized control, which means that there is no preset plan. The produced agents exchange information such as their color, their distance from the output station, etc. Each product merely applies a set of behavioral rules. The aim is to choose the best product to be retrieved in the shortest possible time. The product-type agents have no cognitive ability, but still perform complex tasks.

In this work, characteristics of various ball bearing parameters are studied under different loads and rotational speeds. By using Dimensional Analysis (DA), dimensionless parameters are computed which provides solution for a group of parameters. This analysis can be accomplished by using the Buckingham π-theorem. DA leads to reduction of the number of independent parameters involved in a problem. These independent parameters get expressed as dimensionless groups. These dimensionless groups are always ratios of important physical quantities involved in the problem of interest. In modeling and experimentation, its main function is to reduce the amount of independent variables, simplify the solution, and generalize the results. It becomes an effective method, especially if a complete mathematical model of the investigated process is not known. Moreover, in the present work the Buckingham π-theorem is applied to find the influencing parameter π5 by using the Taguchi method.