Impact of axial preloading on the vibrational response of a double FG porous sandwich beam system surrounded by elastic medium

چکیده مقاله

In this research, the free vibration behavior along with the stability analysis of two parallel three-layer sandwich beams made of porous materials and integrated with metallic face sheets inter-connected by a set of translational springs are assessed. The contemplated structure is placed on Winkler’s elastic foundation and subjected to an axial mechanical load. By considering the effects of shear deformation within the framework of Timoshenko beam model, and using the method of calculus of variations and Hamilton’s principle, the system of governing motion equations of the corresponding structure is obtained and analytically solved via Navier’s method and Fourier series functions for simply supported boundary conditions. The dispersion of internal pores is considered based on three different patterns through the thickness of the beam and its effect on the natural frequencies and endurable buckling loads of the under-investigation model is precisely investigated. Also, the impact of the changes in the porosity coefficient, aspect ratio, thickness ratio, and stiffness of elastic medium is comprehensively explored. Furthermore, the effect of tensile and/or compressive axial preloading on the natural frequencies of the contemplated double-bonded system is perused in detail. The obtained results indicate that changes in theses parameters have a remarkable influence on the stability and vibration performance of the system, and by considering appropriate design quantities, it is possible to attain the desired buckling capacity and vibrational characteristics, while minimizing the weight of the structure.