Numerical study on electromagnetic crimping of tubes

Abstract

Electromagnetic crimping process is a non-conventional, high energy, high-velocity, and solid state impact crimping process. In this process, high energy and high-density electromagnetic field were used to accelerate and impact the flyer tube onto the base tube. A sequential coupled electromagnetic field analysis of electromagnetic crimping was performed using finite element method and boundary element method in the LS-DYNA software. In this study, three types of actuators having cross-sections namely circular, rectangular and square were modelled and analysed for electromagnetic crimping of aluminium Al 3003 and 4340 steel tubes. For this study, the length, number of turns, the pitch and the magnitude of a cross-sectional circumference of the actuators were kept constant. Process parameters such as discharge voltage, standoff distance, and actuator cross-section were varied in this study. Properties like a magnetic field, plastic strain, current density, radial deformation, impact velocity, Lorentz force and Tresca maximum shear stress developed in the flyer tube were compared with all three types of actuators and it was found that the actuator with square cross-section gives the better results. From this study, it was observed that the use of the square cross-section coil is more efficient than that of the circular or rectangular cross-section.