November 22, 2024
Parviz Malekzadeh

Parviz Malekzadeh

Academic Rank: Professor
Address: -
Degree: Ph.D in -
Phone: 077-31222166
Faculty: Faculty of Engineering

Research

Title On the selected problems of time-dependent dynamics of composite truncated conical shells-like aerospace structures
Type Article
Keywords
Truncated conical shells; Nonlinear responses; Ring stiffeners; Porosity; Graphene platelets; Asymmetric moving load; Point supports
Journal Communications in Nonlinear Science and Numerical Simulation
DOI https://doi.org/10.1016/j.cnsns.2023.107717
Researchers Farshid Bahranifard (First researcher) , Parviz Malekzadeh (Second researcher) , Mohammad Reza Golbahar (Third researcher) , Krzysztof Kamil Zur (Fourth researcher)

Abstract

In this paper, the nonlinear dynamic responses of ring-stiffened truncated conical sandwich shells-like aerospace structures fabricated by perfectly bonded graphene platelets (GPLs) reinforced composite porous core and face sheets (GPLRC-PC-FS) under asymmetric internal ring-shaped moving load are investigated. The sandwich shells have edge point supports, which are simulated using the translational and rotational artificial springs. In addition to the open cell porosities, closed cells are also considered and analyzed. The spatially discretized nonlinear motion equations are derived based on the first-order shear deformation theory (FSDT) under the von Kármán geometric nonlinearity assumptions using the Ritz method with Chebyshev polynomials as its admissible basis functions. Then, Newmark's time integration scheme along with the Newton–Raphson method is employed to obtain the shell dynamic responses. After demonstrating the robustness and accuracy of the approach, the influence of rings number, their size and arrangement, core porosity distribution and structure, face sheets, GPLs parameters, moving load velocity and boundary conditions on the shell responses are studied. The results show that the shell dynamic behaviors are significantly affected by porosity, but almost are independent of the type of porosity distribution pattern and its structure (open and closed cell porosities). It is shown that the shell deflection can be minimized by suitably choosing the number of rings, their dimensions and arrangement. Moreover, the nonlinear behaviors of the shells have a significant correlation with the number of point supports and by adjusting the support stiffnesses, the nonlinear dynamic responses of the shells can be reduced.