Structural Design and Tensile Experiment of Connection Node between acrylic and Stainless Steel

Acrylic are widely used as load-bearing structural parts. In this study, the structural design, finite element analysis (FEA) and tensile experiment of the connection node of the acrylic spherical vessel designed for Jiangmen Underground Neutrino Observation (JUNO) are carried out. The acrylic connection node needs to withstand a tensile load of 90 kN for 20 years, and its ultimate bearing capacity is required to be 6 times the working load. Under working load, the stress of the acrylic structure should be less than 3.5 MPa. In the study, a connection node connecting acrylic and stainless steel is designed. By embedding the steel ring in the acrylic structure to connect with the support rod, the acrylic connection node can withstand high loads. A 1/4 symmetric model of connection node is established, and the FEA method is used to solve nonlinear problems such as material nonlinearity and frictional contact. The results of FEA show that the maximum principle stress of the connection node is about 2.92 MPa. By comparing the stress of the FEA results with the experimental results, the relative difference is 7.24 %, indicating that the FEA results are credible. The experiment results also show that the ultimate tensile load of the connection node can reach 1000 kN, which is about 11 times the working load. The breakdown of the connection node occurs at the sharp corner of the groove instead of the maximum stress point. Through the design, simulation and experiment of the connection node, for the brittle materials such as acrylic, the structure should avoid the defects such as sharp corner.