| Abstract: | Force identification is a type of system identification procedure which determines applied force from system responses; it has engineering applications where direct measurements of forces are not feasible. To identify the force, one can consider that the system model and its parameters are known, and then use the measured response of the system to determine the unknown forces. In contrast, postulating the system model and its parameter values is a difficult task, especially when considering a nonlinear system where the model poses many unknowns or inherent mathematical problems. In this research, a more direct way to identify the unknown force without knowing the model of the system is proposed. 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 employs measured accelerations multiplied by effective or optimal weights to estimate the input force. Results using this method show that the force calculated using SWAT accurately predicts the force which excites a nonlinear structure response. The technique could be applied to both constrained and unconstrained structures. |
