Study on buckling behavior of composite sandwich structure with 3D-printed corrugated core under hydrostatic pressure
Topic(s) : Material and Structural Behavior - Simulation & Testing
Co-authors :
Na-Hyun JEON (KOREA, REPUBLIC OF), Hui-Jin UM (KOREA, REPUBLIC OF), Ji-Hwan SHIN , Hak-Sung KIMAbstract :
Fiber reinforced composites are one of the attractive materials in various industrial fields such as automotive, aerospace, and ocean industry due to their high specific stiffness and strength. When designing a sandwich structure using these composite materials, the weight can be dramatically reduced based on high load capacity and corrosion resistance. Due to these advantages, various studies have been conducted to apply carbon fiber (CF) composite sandwich structures to hulls such as ships and underwater vehicles (UWV) in the marine field. Since underwater vehicles are operated in deep water, composite sandwich structure for pressure hulls needs to be designed considering buckling behavior. However, studies on the buckling behavior of composite sandwich structures due to hydrostatic pressure have been mainly conducted theoretically, and there are almost no experiments or analytical models for predicting the behavior of structure.
In this study, buckling behaviors of composite sandwich structures with corrugated core were investigated, and the finite element analysis (FEA) was performed to predict the buckling behavior according to geometric parameters of corrugated core. The composite sandwich structures were composed of skin and core parts. The skin parts were fabricated using CF/epoxy twill prepreg and corrugated core parts was 3D-printed using continuous carbon fiber (CCF) filaments. The experimental buckling tests were conducted with the hydrostatic pressure vessel. The hydrostatic pressure was increased until the failure was observed in composite sandwich structure and the process of buckling failure was observed with high-speed camera. Also, the four strain gauges were attached along the circumference in the middle of the cylinder and two strain gauges were attached in axial direction to compare the deformation behaviors. The finite element model was developed to predict the buckling behavior of composite sandwich structures. The material properties of the skin and core used in the analysis were obtained through mechanical experiments such as tensile and compressive test. Firstly, the linear buckling simulation was performed to calculate eigenvalue for corrugated sandwich structure. Then, the nonlinear buckling behavior was analyzed reflecting initial imperfection. Consequently, nonlinear buckling model could successfully predict the buckling behavior of sandwich structures with 3D-printed corrugated core compared to the experimental results. Furthermore, parametric study was also performed according to geometry of corrugated core through FEA. Different buckling behaviors were observed with respect to the geometry parameters of the corrugated core, and the optimal shape suitable for the purpose of the UWV was proposed.
In this study, buckling behaviors of composite sandwich structures with corrugated core were investigated, and the finite element analysis (FEA) was performed to predict the buckling behavior according to geometric parameters of corrugated core. The composite sandwich structures were composed of skin and core parts. The skin parts were fabricated using CF/epoxy twill prepreg and corrugated core parts was 3D-printed using continuous carbon fiber (CCF) filaments. The experimental buckling tests were conducted with the hydrostatic pressure vessel. The hydrostatic pressure was increased until the failure was observed in composite sandwich structure and the process of buckling failure was observed with high-speed camera. Also, the four strain gauges were attached along the circumference in the middle of the cylinder and two strain gauges were attached in axial direction to compare the deformation behaviors. The finite element model was developed to predict the buckling behavior of composite sandwich structures. The material properties of the skin and core used in the analysis were obtained through mechanical experiments such as tensile and compressive test. Firstly, the linear buckling simulation was performed to calculate eigenvalue for corrugated sandwich structure. Then, the nonlinear buckling behavior was analyzed reflecting initial imperfection. Consequently, nonlinear buckling model could successfully predict the buckling behavior of sandwich structures with 3D-printed corrugated core compared to the experimental results. Furthermore, parametric study was also performed according to geometry of corrugated core through FEA. Different buckling behaviors were observed with respect to the geometry parameters of the corrugated core, and the optimal shape suitable for the purpose of the UWV was proposed.