Research On 3D Printing And Mechanical Performance Of Trifurcated Steel Joints

In a tree structure,joints are the key to the safety of the entire building.Due to the integral casting forming,the cast steel joints can not only realize various complex architectural shapes,but also transfer the welding parts of the joints and components to the outside of the joint area,reducing the residual stress,so it is widely used in engineering practice.However,the current research progress on cast steel bifurcation joints is slow,especially the research on the manufacturing process has not made significant progress for many years.The traditional casting process has lasted for decades,resulting in low precision of the cast steel joints,long manufacturing period,high cost,low energy saving and low environmental protection benefits,and it is obviously difficult to meet the production needs of engineering practice.Therefore,it is necessary to develop a new type of advanced manufacturing technology.3D Printing technology has been rapidly developed as a strategic emerging industry,and has been widely used in aviation,biomedicine and other fields.In recent years,the application of 3D Printing technology in the field of construction production has also attracted a lot of attention.This paper explores the application of 3D Printing technology to replace the traditional casting process to produce many complex new joints.Using the relatively mature SLM process in 3D Printing technology,the main process parameters affecting the density of molded parts were optimized by orthogonal analysis.Then,a typical trifurcated steel joint scale model was printed and manufactured under the optimal process parameters,and the aging and solution treatment were performed.Finally,the joint space loading test and finite element simulation are carried out to analyze the destruction process and mechanism of the 3D Printing bifurcation joint.The research results show that the preferred process parameters for manufacturing joints using 316 L stainless steel powder under the SLM process are: scanning power 150 W,scanning speed 700 mm / s and scanning interval 0.09 mm.Using these process parameters,a tree-like trifurcated steel joint scale model was successfully printed,and good surface quality and geometric accuracy can be obtained after heat treatment.The results of space loading test and finite element analysis show that the 3D printing joint has good mechanical performance,and the failure mechanism and failure model are similar to the traditional casting joint.Compared with the traditional casting process,the manufacturing of joints with complex geometric shapes by using 3D Printing technology does not need to make molds in advance.It has higher manufacturing efficiency,more free structural appearance,and has outstanding material saving and environmental protection benefits.