The mechanical characteristics of 304 stainless steel T-joint and lattice truss panel structure with pyramidal core were extensively investigated by the combinational methods of the experiments, finite element simulation and analytical model. The experimental results reveal that a T-joint with 2.25kW laser welding power, 2.5m/min welding speed and 5mm separation performs the better ultimate tensile load and strength ratio. The mechanical responses of T-joints are mainly dominated by elastic-plastic deformations. The laser welding reduces slightly the elasticity, ultimate tensile strength and fracture toughness of the structure. The joints present typical ductile fracture once the loads reach fracture strength. Under three-point bending test, the mechanical curve is divided into elastic, yield and failure region, and the deformation characterizes and failure modes are tension and shearing stress controlling. The results are verified by the FEM simulation.
Keywords laser welding, lattice truss panel structure, mechanical properties, high-efficient compact heat exchanger