An Approach to Monitor Bolt Faults in Two-Dimensional Structures Without Reference

Monitoring potential bolt faults is very necessary and meaningful to keep structures in healthy operation. For this purpose, an improved approach to monitor bolt faults in two-dimensional structures without reference is proposed. In the new method, the nonlinear dynamic behaviors of the structure to be monitored are studied by a general multi-degree-of-freedom (MDOF) mode with nonlinear elements. By exciting the structure many times with the same excitation and the local structural modification method, only nonlinear features from the structure to be monitored are defined. Based on these features, a novel fault index and corresponding improved approach are proposed and explained. With some numerical examples on a two-dimensional structure, the effectiveness and reliability of the method are fully verified.