Design and Optimization of Web Fillets for Commercial Vehicle Crankshaft for Improving SCF and Theoretically Correlated 2016-01-1342

Crankshaft is one of the critical components of an engine (5C: cylinder head, connecting rod, crankshaft, camshaft and cylinder block). It is subjected to repetitive and dynamic loads due to cyclic operation of an engine and inertia forces. Due to uneven mass distribution, failure zones occur near fillets and holes in journal locations during operation of the engine. Hence, this topic was chosen because of increasing interest in higher payloads, lower weight, higher efficiency and shorter load cycles in crankshaft equipment.

Calculation of Crankshaft strength consists initially in determining the nominal alternating bending and nominal alternating torsional stresses, which multiplied by the appropriate SCF (Stress Concentration Factor), result in an equivalent alternating stress. This equivalent alternating stress is then compared with the fatigue strength of the selected crankshaft material. This comparison will show whether or not the crankshaft concerned is dimensioned adequately. Hence, SCF is main focus point. The present study emphasizes on a CAE based approach for prediction of SCF for crankshaft web fillets. Using FE Solver (Optistruct), the dimensions and shape of the web fillet are optimized for Improving SCF. On the basis of the analysis various design parameters of web fillet are determined and finally the results obtained from FE analysis were theoretically validated.