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In this paper, the vibrational and buckling analysis of a cylindrical sandwich panel with an elastic core under thermo-mechanical loadings is investigated. The modeled cylindrical sandwich panel as well as its equations of motions and boundary conditions is derived by Hamilton's principle and the first-order shear deformation theory (FSDT). For the first time in the present study, various boundary conditions is considered in the cylindrical sandwich panel with an elastic core. In order to obtain the temperature distribution in the cylindrical sandwich panel in the absence of a heat-generation source, temperature distribution is obtained by solving the steady-state heat-transfer equation. The accuracy of the presented model is verified using previous studies and the results obtained by the Navier analytical method. The novelty of the present study is considering thermomechanical loadings as well as satisfying various boundary conditions. The generalized differential quadrature method (GDQM) is applied to discretize the equations of motion. Then, some factors such as the influence of length-to-radius ratio, circumferential wave numbers, thermal loadings, and boundary conditions are examined on the dynamic and static behavior of the cylindrical sandwich panel. [ABSTRACT FROM AUTHOR]

Since train’s frontal nose is the first part of the train which is damaged at the frontal impact, specific attention should be paid to the design of this part. In this study, an effort has been conducted to the design of a nose with light weight which can absorb maximum amount of energy that is possible during a frontal collision. To this aim and with attention to aerodynamic considerations, application of aluminium honeycomb sandwich panel has been studied. This paper includes two main parts. The first part is dedicated to the simulation of aluminium honeycomb sandwich panel, while the frontal collision of nose with different internal layer thicknesses of honeycomb and various nose lengths have been simulated in the second part. Finite element method using LS-DYNA commercial package has been used for the numerical simulation. The results have been validated with available experimental results and an acceptable agreement has been observed. [ABSTRACT FROM AUTHOR]

In impulsive orbital maneuvers, thrust vector misalignment from the center of mass (C.M) results in a large disturbance torque. In this paper a thrusting maneuver system is proposed and studied which is based on the combination of a one degree of freedom (1DoF) gimbaled-thruster, two reaction wheels (RWs) and spin-stabilization. The main goals are disturbance rejection and thrust vector stabilization without using reaction control systems (RCS). The nonlinear two-body dynamics of the proposed system is formulated. The controller design is formulated as a multi-objective optimization problem where the peak-value of the control input and H ∞ performance are the cost functions. Based on the peak-to-peak gain minimization, the accuracy of the linearized model can be guaranteed. The optimization results give many optimal controllers which are acceptable for a thrusting maneuver. The simulation results illustrate the applicability of the proposed method in presence of the sampling effects of the control inputs., (Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.)