Development and Application of Buckling Estimation Method in Engine Connecting Rod

In prediction of the critical buckling load of structures, Merchant-Rankine formula is very powerful considering both elastic buckling load and plastic material behavior. However this formula can't be applied to the connecting rod of engine because of the difficulty in defining the end conditions and the geometry change in the shank unfortunately. In this study, we modified Merchant-Rankine formula with aid of FEA and a subspace iteration method. The developed method here was verified by buckling experiments and applied to several connecting rods. As a result, the guideline of buckling failure is built using the buckling safety factor defined here.