As an engine operates faster and faster, the joint forces between engine components get bigger and bigger. Thus in order to design engine components such as crank shaft, connecting rod, etc., the reliable prediction of joint forces is very important.
In this work, the crank-connecting rod system was studied to derive joint forces. The system was modeled with an assemble of rigid bodies and the joint forces were obtained from the dynamic force equilibrium of each component. Then the forces were proved by comparing with experimentally measured strain from a strain gage mounted at connecting rod. Also the sensitivity for the joint forces with design parameters such as balancing weight, the position of center of gravity of connecting rod, etc., was carried out. These sensitivity analysis will be very helpful to design engine components.
