Force Identification from Structural Response
Abstract
Force identification is a type of system identification procedure which determines applied forces from system response measurements. To identify the force, one can consider the system model and parameters which are known, and then use the response that is measured to determine the unknown forces. In this research, a more direct way to identify the unknown force without knowing the model of the system is proposed. However, to postulate the system model and its parameters is difficult to justify, especially when considering a nonlinear system where the model poses a great deal of unknowns or inherent characteristics of the mathematical problem. The approach called the sum of weighted acceleration technique, SWAT, is a method that can predict input forces with measured linear and nonlinear structural responses. SWAT uses measured accelerations multiplied by effective or optimal weights to estimate the input force. The effective weights are the coefficients of an equivalent mass at each acceleration location. Once the effective weights are determined, the unknown input forces can be predicted by using a mathematical formulation, which is the goal of force identification. The approach of SWAT was validated in the time and frequency domain. For practical applications, the approach of SWAT was extended to a finite element approach for further validation of larger elastic structures. The results show that the force calculated from SWAT accurately predicts the force which was inputted to the structure. Structural analysis. Dissertations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1999
- Accession Number
- ADA220845
Entities
People
- Timothy J. Kreitinger
Organizations
- Air Force Institute of Technology