On static and dynamic stability of bio-inspired composite plates under variable axial load

Recently, bio-inspired composite structures with helicoidal schemes and designs are used in many applications instead of the classical composite structures due to their high damage tolerance and high impact energy absorption properties. However, their static and dynamic stability under variable axial loads is not addressed. Thus, this study intends to analyze the uniaxial, biaxial buckling and vibration behaviors of bio-inspired helicoidal composite plate under variable in-plane edge load, for the first time. Based on the first order shear deformation theory (FOSDT), mathematical model of helicoidal orientation schemes of bio-inspired composite plate structure under variable in plane edge loads are presented. Six different profiles of the axial loads are included in the analysis. The governing equilibrium equations and the associated boundary conditions are deduced in detail. After that, the two-dimensional differential quadrature method (2D-DQM) is exploited to discretize the buckling problem in the space domain and convert the linear partial differential equations with variable coefficients to linear eigenvalue problem in terms of displacement field. Combining the separation of variables method and 2D-DQM to solve the linear vibration problem with variable in-plane axial load. Numerical analysis is presented to discuss effects of the fiber orientation schemes, type of axial load, boundary conditions, on the buckling loads, natural frequencies, and mode shapes of bio-inspired composite plates. The proposed methodology as well as obtained results are supportive in design and manufacturing of advanced bio-inspired composite structures which can be widely in medical, environmental as well as energy-saving technologies.