Impact force identification from known acceleration responses using Gaussian Elimination with Partial Pivoting Inverse Technique
Authors: Rahman, A.G.A., Noroozi, S. and Yee Khoo, S.
Journal: Mechanical Systems and Signal Processing
Finding the in-service dynamic forces, their location and their line of action on structure are necessary during its design, development and modification stages. For example in automobiles, the impact force caused by bump is the most common and disruptive impulse that a car experiences, resulting in shock and vibration that can cause damage to the car or can transmit into the cabin and the passengers compromising the quality of ride and comfort. There are no transducers configurations exist that can directly measure these forces. A methodology involving determining the structure Operating Deflection Shape (ODS) and the Frequency Response Function (FRF) at discrete location and the inversion of the FRF to evaluate the dynamic force distribution is proposed here. A test rig simulating an automobile was used here. The vibration responses caused by an impact force at a location were evaluated using ODS analysis. The FRF of the system were obtained using FRF measurement. The Gaussian Elimination with Partial Pivoting (GEwPP) inverse technique was used to calculate both the impact force time history and its impact location simultaneously. The result showed good agreement between the calculated impact force’s amplitude and location with the measured impact force and locations.
Preferred by: Siamak Noroozi