Proceedings of The 8th International Conference on Innovation in Science and Technology
Numerical Comparative Modal Analysis of Connecting Rod between Fixed Crankpin and Fixed Piston Pin
Getachew Admassie Ambaye
Connecting rods are subjected to a tensile (inertial force), compressive (gas pressure), and bending (eccentricity) loadings. The boundary conditions used for the determination of its natural frequency depends on the loading type. For free vibration analysis, when the piston moves upward the crankpin needs to be fixed and free piston pin, while when it moves down the piston pin should be considered as a fixed and free crankpin. This paper presents a numerical (ABAQUS software) comparison of the first six dominant mode shapes and natural frequencies of the connecting rod when it is fixed at the crankpin and free at the piston pin (case 1) and fixed at the piston pin and free at the crankpin (case 2) of an optimized geometry that found from literature. The mode shapes and natural frequencies of the two cases are compared, and it shows that the natural frequency of case 2 is lower than case 1. Therefore, for design purpose, the loading frequency should be less than the natural frequency of the connecting rod when it is fixed at the piston pin.
Keywords: Mode shape, Natural frequency, Load frequency, Fixed crankpin, Fixed piston pin .