Research On Roll Forming Technology For High-strength Honeycomb Half-cell Structures

Metal honeycomb core is a kind of multi-cellular honeycomb nests of bionic material. It has advantages of low density, low rigidity, strong shock resistance and compressive deformation controllable characteristics, which are widely used in the aerospace landing and anti-collision structure of the high-speed train. One of the most crucial process in manufacture of high-strength aluminum honeycomb core is forming of high-strength honeycomb half-cell structures The quality of honeycomb half-cell structures directly affect on intensity of the metal honeycomb core and its manufacturing. Therefore, the research on key technologies of honeycomb half-cell structures roll forming has great significance. The main contents are as follows:(1) The roll forming theory of honeycomb half-cell structures are studied the mechanical performance of raw materials was tested, and it were analyzed that the stress and strain of material in the roll forming process when the material is elastic-plastic bending deformation. It was emphatically analyzed that the roll forming process was impacted by the teeth number of forming roller, tooth profile of forming roller and material mechanical performance.(2) The ANSYS/LS-DYNA FEM software was used for finite element simulation of roll forming process, realistic theoretical models and simulation conditions was established, It is rapid modeling for the roll forming of honeycomb half-cell structures, and it Realized the automation of finite element analysis.(3) The defects of honeycomb half-cell structures was analyzed in the process of roll forming, the influence of the teeth number of forming roller on roll forming has been studied, it was showed that the forming effect is the best when the teeth number of forming roller is40. It put forward that honeycomb half-cell structures were formed by using trapezoidal tooth profile conjugate forming roller. It effectively eliminates the defect of honeycomb half-cell structures which was caused by meshing instability when using traditional trapezoidal tooth profile forming roller. The influence of material mechanical properties on the forming quality of honeycomb half-cell structures has been analyzed, and the results show that the yield strength of the material, which is used in the roll forming, should not be higher than400MPa.(4) According to the finite element simulation and optimization results of roll forming, the roll forming device was made, and experiments were carried out. The experimental results is consistent with the finite element analysis results which is the relationship between the forming rollers of teeth, tooth profile, mechanical properties of materials and the quality of formed parts. It provides a theoretical basis for the optimal design of the roll forming device.