Estimation of the force and the noise generated by the random impact

Aiming to estimate noises generated by random collisions of gravels to a car body, the time history of impact force is estimated with various impact conditions. Many impact experiments with a force sensor having various head chips mounted on the tip of pendulum are carried out and reveal the effects of impact velocity and mass, radius curvature and material of impactor to the impact force. The approximate function to express time history of impact force is defined and identified with the measured results. The time history of impact forces can be estimated with an adequate accuracy. By using the estimated impact force, the noise radiation due to random impacts can be estimated. The estimated noise agrees almost well with the measured noise.