استفاده از روش نوار محدود برای تجزیه استاتیکی صفحات ساندویچی با هسته موج دار
Abstract
1- Introduction
2- Theory
3- Boundary conditions
4- Numerical results
5- Conclusion
References
Abstract
Free and forced vibration and static analysis of corrugated-core sandwich plates are investigated in this study by employing the classic finite strip method. The 3D corrugated-core plate is converted to a 2D orthotropic continuum model by considering some equivalent elastic constants. Various boundary conditions and different features of these plates are explored and the geometric and mechanical factors influencing their responses, such as displacements, rotations, moments and shear forces, are evaluated. Because of the significant effect of the shear stiffness on the behavior of corrugated-core sandwich plates, the first order shear deformation theory (FSDT) is used to analyze the plate. Due to the comparatively low shear to flexural stiffness ratio of these plates compared to ordinary plates, the convergence of the results is relatively slow. Therefore, a fast numerical technique such as finite strip method which yields effective reduction of calculation cost is employed. A MATLAB program is developed to obtain the results and the validity of the proposed method is evaluated by comparing the results with those presented by previous researches.
Introduction
Corrugated-core sandwich plate (CSP) is a three-layered composite structure that consists of two main parts: a corrugated sheet (called the core plate) in the middle of the sandwich plate which has a sinus or trapezoidal cross section composed of high-strength or soft material, and two rectangular flat thin sheets that are connected to the top and bottom of the core, called the face plates. These plates are generally made up of high-strength materials such as steel or carbon fiber. Corrugated sandwich plates can be widely used in construction industries because of their simple handling and manufacturing compared with other types of composite plates. Some of the advantages of CSPs are as follows: • By increasing the gap between the two face plates and placing the core between them, the section moment of inertia and the load capacity of the structure also increase. • The weight of CSP decreases due to the presence of empty spaces in the core. These spaces also provide the possibility of passing the facilities. • The ability to absorb and deplete energy increases by using different materials in cores. • Carrying and installing CSPs is easier than ordinary plates. • The ability to isolate heat and sound in such plates is reachable by embedding insulating materials as core plate or in the middle of empty spaces of the plate. It is notable that corrugated core sandwich plates are periodic structures, which are capable of developing the wave stop bands (or band gaps) that acts like a directional frequency filter which restricts the free propagation of elastic/acoustic waves [1–4]. This effect can reduce the noise or vibration to some extent.