Santos, M., Manini, R., Curi, J., and Chiqueti, C., "“U” Bolt Torque Influence over Leaf Springs," SAE Technical Paper 2014-36-0024, 2014, doi:10.4271/2014-36-0024.
”U” bolts are fixing elements and they are used to clamp an elastic joint. From the past, they still looking as an old design and unfortunately, suspension engineers are not specialists in fasteners and elastic joints. That is why we will show important assumptions and concepts to design and specifications this clamp element “U” bolt and its influence over leaf-springs.Currently, “U” bolt is used to clamp an elastic or elastic-plastic joint of heavy duty suspension, formed by leaf-spring, axle, spring pad, “U” bolt plate. This kind of suspension is typically used to trucks, buses and trailers.We are wondering, which one important assumption that an engineer must be careful when designs a new suspension changing from old designs to an updated technology.We provide a theoretical analysis and a FEA analysis to compare torque efficacy x leaf-spring reactions and what are effects this relationship can cause in a suspension.To have a shortest development time and provide back an expected result from the suspension system, engineers should to consider more and new assumptions, evaluate virtual and practical performance of leaf-springs with “U” bolt designed to clamp all elastic joint and even the correct torque specification to the “U” bolt.