Study On Mechanical Properties Of Ellipsoidal Cylindrical Concave-convex Sandwich Plate

Sandwich structures have been widely used in the fields of vehicles,ships,aerospace,housing construction,and other fields due to their excellent mechanical properties such as high light weight,light weight,strong energy absorption,noise reduction,and vibration reduction.As a kind of sandwich structure,the concave and convex sandwich panel is taken as the research object in this paper to explore the bending characteristics and energy absorption characteristics of the concave and convex sandwich panel.Firstly,based on the theory of elastic mechanics,the theoretical expression of the bending stiffness of elliptical cylindrical concave convex sandwich panels is derived.Then,ABAQUS three-point bending simulation is performed on them,and the two are compared to verify the accuracy of the simulation analysis.Furthermore,the influence of section parameters on the bending performance and strength utilization of each plate was analyzed.The research results show that the theoretical solution of bending stiffness established in this paper is highly compatible with the simulation solution.Increasing the thickness of the panel and the height of the core plate can significantly improve its bending performance.The thickness of the core plate,the semi major axis a and the semi minor axis b have little influence on the bending performance.The plastic failure of the upper panel and the core panel almost simultaneously results in the highest strength utilization rate.To improve the strength utilization rate of the lower panel,the core plate thickness should not exceed the panel thickness,and the core plate height should not be too high.Secondly,ABAQUS was used to study the deformation mode and energy absorption characteristics of elliptical cylindrical concave convex sandwich panels under quasi static compression loads,and the effects of cross-sectional geometric parameters and the number of cores on their energy absorption were discussed.The results show that the upper and lower panels of the concave-convex sandwich panel have almost no bending deformation,and the core of the core plate presents a drum shaped deformation.Within a certain range,appropriately reducing the thickness of the panel,increasing the thickness of the core plate and the number of protruding cores from the core plate can significantly average the compression force and specific energy absorption;As the height of the core plate increases,its specific energy absorption gradually increases,but the average compressive force first increases and then decreases,reaching its maximum at a height of 16 mm;The influence of the semi major axis a and the semi minor axis b on the average compressive force and specific energy absorption is small.Finally,ABAQUS was used to study the failure modes and energy absorption properties of elliptical cylindrical concave convex sandwich panels under local impact.The effects of cross-sectional geometric parameters and the number of cores on their energy absorption were discussed.The main failure mode of the upper and lower panels is tensile failure,and petal like tear failure occurs in both panels;The core plate mainly produces combined failure of compression,bending,tension,and shear;Within a certain range,increasing the thickness of the upper and lower panels,the thickness of the core plate,and the number of core plates can significantly improve the impact resistance of the concaveconvex sandwich panel;Increasing the height of the core plate will reduce the impact resistance;Appropriate semi major axis a and semi minor axis b can improve their impact resistance,but have a small impact.