Establishment of Methodology for Prediction of Fatigue Life of Connecting Rod through Virtual Simulation

The application of virtual simulation of Engine components has become an integral part of design and development process. Virtual simulation offers opportunities to reduce number of physical tests during design verification and validation and thereby helps in achieving considerable reduction in development time and cost.

This paper explains a case study that was essential for assessment of strength & fatigue analysis of diesel engine connecting rod as a part of engine development program for power upgrade through Turbo charging. The methodology adopted simulates major loading conditions for Compressive& Tensile stresses & fatigue life of connecting rod. Finite element analysis was done to calculate static displacement, strain and stresses under maximum compressive and tensile loading which were then used for critical point evaluation. Fatigue analysis and longevity is assessed through ANSYS. To validate the methodology developed; accelerated physical fatigue testing was carried out on the rig and results were compared. A very close correlation could be established between FEM results and failure on physical test samples. The repetitive results helped us to set appropriate design factor of safety for such applications. This methodology can be used to optimize the design of connecting rod and virtually validate in early stage of product design cycle thereby reducing no. of prototype tests.