Experimental and numerical studies of a multi-leaf clamped lap joint design for aluminium bus bar applications

A low electrical resistance, multi-leaf, clamped bus bar connection has been proposed to facilitate installation and removal of related process equipment. Whilst elastic deformation of the bus bar contact members will allow for some variation in thickness, the design may be sensitive to relatively tight tolerances on bus bar thickness due to the highly constrained arrangement of clamping across the multiple bus bars in contact. Experimental and numerical studies were conducted at up to 200 °C operating temperature to determine the exact impact of variation in bus bar thickness on the distribution of contact pressure and hence impact on contact resistance for a multi-leaf clamped lap joint design for aluminium bus bar applications. The studies show that when a significant gap is introduced into the highly constrained arrangement, there is insufficient deformation possible in the contact members to close this gap, even at 200 °C operation. Both the experimental and modeling studies suggested there would be a 12 mV penalty for the proposed connection, when one of the four parallel contact pairs are not in contact.