Wheel Analysis Process Considering Bolt Torque Sequencing for Assembly and Disassembly

This paper is centered on developing a methodology to simulate actual physics of the assembly and disassembly process for rear wheel components of the tractor / off highway vehicle. The components, cast wheel and sleeves, are having interference fit and are assembled through sequential bolt torquing. Effect of different torque values, torque sequence pattern and number of torquing cycles on the structural integrity of the components after assembly is studied in this process. The methodology also encompasses evaluation of residual strains during the assembly and then subsequent disassembly process of sleeves and cast wheel, while reckoning different non-linear material models for nodular and gray cast iron. The process predicts the loosening behavior of the bolts during assembly process and eventually helps to find optimum bolt torquing pattern with minimum preload loss. These are valuable inputs for factory as well as end customers to reduce number of retorquing cycles. Strain pattern in parts highlights the regions that need design changes from assembly process point of view. Automation during the process incorporated agility and enhanced efficiency by 70%. The high-fidelity models helped to correlate strains and bolt working loads with actual field tractors and this would be an accepted standard process for evaluation of all wheel assemblies going forward.