Stinger mass compensation problems are investigated experimentally for the case when the load cell is mounted 0n the stinger's exciter end. Two test cases are performed experimentally using three different mass compensation methods. The first test uses a rigid mass specimen while the second uses a double cantilever beam specimen. The experimental results show that the measured frequency response function (FRF) can be underestimated if mass compensation is based on the stinger exciter-end acceleration and can be overestimated if the mass compensation is based on the structure-end acceleration because of the stinger's compliance. The mass compensation that is based 0n two accelerations is seen to improve the accuracy considerably. However, experimental difficulties have been found in predicting the resonant magnitude for all three mass compensation methods.

by ASL