Optimal design of laminated composite torque wrench

This paper presents the design and manufacturing process of a laminated composite torque wrench. The tool body is treated as a cantilever sandwich composite plate made up of long and short fiber layers. The C° (penalty) element in which the exact expressions for determining shear correction factors are adopted is used to perform the structural analysis of the sandwich composite plates subjected to transverse loads. The optimal lamination arrangement of the composite torque wrench for maximum stiffness is studied via a multi-start global optimization technique. In the manufacturing process, the long and short fiber layers are joined together by a metal interface ring. The handle is a honeycomb structure, where the interior is a short fiber sandwich layer while the exterior is coated with a long fiber layer. Its characteristics include base composite material, interface ring, internal wall of tooth surface and exterior projected rib. Several designs of laminated composite sandwich torque wrenches are given to demonstrate the feasibility and applications of the proposed method.