Analysis of mechanical and vibration behavior of sandwich panels is very important in aerospace and mechanical engineering structures. The main feature of these panels are anisotropic behavior and high strength to weight ratio. Such panels include corrugated core with different geometries are within the panels. Corrugated panels are special kinds of structures that their ability to withstand loads in one direction and be flexible in other direction has made them suitable for morphing structures. The principal application of this type of structures is in the morphing airfoils where they are subjected to the aerodynamic loading in various flow regimes. Considerable amounts of researches were done that focused on static and dynamic behavior of these special panels. The research aim is to study the mechanical and vibration behavior of corrugated core with variable amplitude under tension, bending and vibration tests. First, to evaluate the tensile and flexural stiffness of corrugated core with variable amplitude, two models of core was designed to fit in aircraft airfoil and three-point bending and tensile tests were performed on them and force-displacement curves were exploited. Numerical and analytical solutions to simulate the mechanical behavior of corrugated core with variable amplitude in tension and bending is presented. By using the energy method (Castigliano’s method), tensile and flexural stiffness of corrugated core with variable amplitude calculated analytically. Two models of corrugated core with variable amplitude was modeled in ABAQUS (an FEM package), and force-displacement curves were exploited. By comparing the results of tests and finite element simulation, ability of created model by finite element method to predict the mechanical behavior of corrugated core is shown. Also, airfoil with corrugated core simulated in ABAQUS and tensile and flexural stiffness of that exploited from force-displacement curves. The results showed that the flexural and tensile stiffness of the airfoil was increased by the core placed there .Then, the vibration behavior of corrugated core with variable amplitude was studied and by free-vibration stimulating of the core, time waves related to each vibration mode were recorded by the accelerometer sensor and then the natural frequencies and damping coefficients of each corrugated core mode were extracted by FFT diagrams. Finally, by using ABAQUS , the finite element simulation were carried out to model the vibration behavior of corrugated core with variable amplitude to verify the natural frequencies of the experimental and finite element results. Good proximity between the experimental and numerical results were observed. Keywords: Corrugated core with variable amplitude; Tensile stiffne flexural stiffne Natural frequency, Finite element method