COMPARISON OF FORCE RECONSTRUCTION METHODS FOR A LUMPED MASS BEAM

Two extensions of the force reconstruction method, the sum of weighted accelerations technique (SWAT), are presented in this article. SWAT r equires the use of the structure's elastic mode shapes for reconstruct ion of the applied force. Although based on the same theory, the two n ew techniques do not rely on mode shapes to reconstruct the applied fo rce and may be applied to structures whose mode shapes are not availab le. One technique uses the measured force and acceleration responses w ith the rigid body mode shapes to calculate the scalar weighting vecto r so the technique is called SWAT-CAL (SWAT using a calibrated force i nput). The second technique uses the free-decay time response of the s tructure with the rigid body mode shapes to calculate the scalar weigh ting vector and is called SWAT-TEEM (SWAT using time eliminated elasti c modes). All three methods are used to reconstruct forces for a simpl e structure.