Monitoring Impact Events Using a System-Identification Method

An inverse method based on a system-identification technique for identifying impact events on a complex structure with built-in sensors is presented. The method using the transfer functions in the system-identification technique identifies the location and force time history of an impact event on a structure without the need of constructing a full-scale accurate structural model or of acquiring excessive training data on the structure, such as neural-network techniques. The system transfer functions for the entire structure are constructed by two sequential procedures: 1) limited impact tests at selected points to establish the system transfer functions from the selected points to a sensor on the structure and 2) an interpolation function approach based on a linear finite element to approximate the system transfer functions from a point inside four neighboring selected points to the sensor. Comprehensive tests with various impact situations verified the accuracy of load and position predictions by the proposed method.