Multivariate Quadratic Nonlinear Regression Model of the Ultimate Pull-Out Load of Electrohydraulic Expansion Joints Based on Response Surface Methodology

Electrohydraulic expansion joining has great potential for the light weight and high strength thin-walled pipes due to its strain rate. Based on central composite design (CCD) of response surface methodology, multiple experiments electrohydraulic process were performed. The multivariate quadratic nonlinear regression model between parameters (discharge voltage, wire length, diameter) ultimate pull-out load joints was established. results revealed that discharge length diameter all had a significant effect load. voltage most effect. interaction optimal parameter combination = 6 kV, 10 mm, 0.833 mm) obtained verified through experiments. This study would provide guidance choice in real applications.