Simulation Study On Buckling Resistance For Lattice Truss Core Sandwich Cylinder

Lattice truss core structure is a kind of sandwich structure consist of two layers of skin and the inner lattice truss,which is widely used in aerospace,shipbuilding,construction and other fields for its advantages such as lightweight,good damping and insulation properties,high modulus,and good flexibility in design.In this paper,the relationship between parameters and performance is established and the buckling capacity of pyramidal,tetrahedral and KAGOME core sandwich cylinder with different structural parameters is discussed by meas of FEM.Displacement relation method is used to get the relationship between relative density or equivalent modulus and structural parameters,which is examined by compression test.And the influence of skin thickness,number of cells and staff thickness to global stability through orthogonal test by analyzing the buckling characteristic under axial and external pressure using ANSYS workbench.It is found that the load multiplier is positively related with structural parameters.The skin thickness impacted a lot and the core is weak in comparison when a sandwich cylinder is under axial pressure,so at that time change the parameters of core has little effect.Anti buckling capacity of the cylinder with 3mm skin is better than the the skin thickness of 1mm and 2mm.Core parameters influenced deeper when the sandwich cylinder is under external pressure.The cell has the highest equivalent modulus when the angle between staff and skin is 45 degree.The tetrahedral core sandwich structure has the best stability under external pressure.The cylinder of which the lattice parameters for skin thickness 3mm,cell number 200 and staff thickness 4mm has the best buckling resistance.The stability begin to decrease when the thickness of the 200 cells and 4mm staff tetrahedral cylinder is less than 3mm.Anti buckling capacity and the heat insulation ability of the sandwich cylinder with different configuration parameters under thermal loading are studied.It is found that the outer skin was easier to buckle due to heat concentration,so any way which is propitious to conduct heat will enhance the stability of the structure under thermal load and decrease heat insulation ability.The main parameter affecting the ability of resisting thermal buckling is the number of cells,followed by staff thick,and the last is the thickness of the skin.Meanwhile,the tetrahedral structure has the best insulation ability,while the KAGOME structure has the best thermal buckling performance.In coupled thermal-mechanical analysis,the effect of external pressure is most likely to make sandwich cylinder buckling,whose F ratio was 14.255.Followed by thermal load,and the effect of axial compression is the least obvious,of which the F ratio are 2.158 and 1.547.For the design of the lattice truss core cylinder under coupled field,parameters should be decided basing on the strength of main load in the environment.