The Effect Of T-joint To The Sandwich Plate Bending Performance

With the development of the maritime industry, people on the bigger, faster and growing demand for lighter vehicles, save resources, reduce energy consumption environmental protection and sustainable development become the main issues facing the development of vehicle. Laser welding is a new sandwich board structural panel, it is composed by the upper and lower panels and supporting core board, supporting core board and panels are connected by laser deep penetration. Metal sandwich panels with a light weight, high specific stiffness, high strength characteristics, based on these advantages, metal sandwich panels used on surface ships, aircraft and other means of transport, in order to improve its carrying capacity and dynamic.In this thesis, Ⅰ type sandwich board as the research object, BS960and SPFH780two high-strength type Ⅰ sandwich board were extended three-point bending test to research the flexural properties of sandwich panels of type Ⅰ, and use the ABAQUS finite element analysis software computer the high-strength BS960steel sandwich panels of different welded joints, root gap, weld offset and other structural panel thickness.Through trial on the two high-strength type Ⅰ sandwich board and the result of BS960high strength steel sandwich plate finite element structural analysis found that:(1) T-joint damage and failure occurs during the test of BS960high strength steel sandwich panels thickness with5mm panel;2.5mm panel thickness of SPFH780high strength steel sandwich panels for the panel buckling failure;(2) thick panel Ⅰ type sandwich structure, the effect of T-joints strength on the flexural properties of the structure is significant;(3) among the geometric parameters of laser weld joints that connect the thickness of the width of the joint space, root gap and offset joints impact on T-joint strength, the T-joint weld width are the main factors, namely the width of T-joint connection would influence the Ⅰ type sandwich plates in bending performance greatest;(4) the increase in T-joint connection width can significantly improve the performance of Ⅰ-type sandwich plates, root gap increases may impair the performance of Ⅰ-type sandwich plate bending, and the offset of most dangerous T-joint have little effect on the bending properties of type Ⅰ sandwich boards and can be ignored;(5) BS960high strength steel sandwich panels most dangerous T-junction occurs in the middle node on the panel, neither close to head office nor the supports;(6) during the preparation of Ⅰ-sandwich plate, panel thickness of sandwich panels will be a key factor affecting the width of the T-joint connection;(7) T-joint connection width of the sandwich plate impact on bending stiffness greater than it on the shear stiffness;(8) the impact of panel thickness on the bending stiffness of sandwich board is less than the shear stiffness. Through the finite element simulation on different panel thickness corresponding different weld width of Ⅰ-type sandwich plate and comparative analysis the finite element results, selected a structure to match the joint failure and panel yield.