Linearity investigation from a vibratory fatigue bench

Abstract

High-cycle fatigue behaviour of structures can be obtained through vibratory tests using frequency response functions or transmissibilities. To this end, this study deals with the qualification of the vibratory fatigue bench developed at the Laboratory of Mechanic of Normandy. This bench uses an electrodynamic shaker which can reach excitation frequencies that are higher than conventional fatigue machines. To carry out relevant tests, the capacities of the test bench must be well known. Correlations between excitation and response were investigated to determine the allowable setpoints to maintain linearity between the input and output signals to validate our system. The difficulties related to the experiments were presented and discussed.

Experimental Modal Analysis of an Aircraft Wing Prototype for SAE Aerodesign Competition

“…The purpose of the stinger is to uncouple the effects of the shaker from the structure, and to transmit only axial loads to the structure, reducing the possibility of inserting transverse forces. The impact of coupling interaction between electrodynamic shaker and structure is treated in [42,43]. Hence, the use of the stinger ensures a correct excitation of the wing and uncoupled shakerstructure.…”

Experimental strain‐based vibration control to obtain the fatigue strain limit by the staircase method

“…Another common approach is calibrating the input and output(stress/strain) of test system. Gautrelet et al [11] used the linear relationship between the response in strain or velocity and the excitation in acceleration to calibrate the strain level of fatigue zone. George et al [12] used a laser sensor to measure the velocity of the specimen to calibrate to the maximum strain.…”