Vibration Fatigue Analysis of Motorcycle Front Fender

Two wheelers are becoming increasingly popular in India. Competition in this segment has made the product developers to develop the vehicles with short time without compromising durability. Vibration Fatigue Analysis is an advanced technique to evaluate the life of components undergoing vibration, thereby the drastic reduction in durability evaluation time. Front fender is a styling component generally made with plastic material and undergoes vibrations. Therefore, it is very difficult to design the fender based only on static load cases. Vibration fatigue analysis using Finite Element Method (FEM) is used to ensure the durability in design stage itself. Various customer usage modes of the vehicle are considered. Accelerometers and strain gauges are mounted on the fender on appropriate locations. First, the instrumented fender is mounted on the electro dynamic shaker. The fender is excited with sinusoidal inputs. FE Model is made using shell elements and harmonic response analysis is done with the same inputs as in shaker. FE based stress response result is validated with the measured responses. Using the predicted stress responses fatigue life offender is calculated. Then the fender is assembled with the vehicle and the vehicle is driven in customer usage modes. Acceleration, frequency and strain data are measured for each of these modes. The measured data are used for arriving at test standard also. The FE estimated life is compared with the target life and based on the comparison the design is cleared for mass production.