A nonlinearity measure-based damage location method for beam-like structures

In our previous work, nonlinearity measure was proposed for assessment of nonlinearity severity of distributed parameter systems (DPSs). However, its engineering applications are restricted due to the high-dimensional optimization procedure in the nonlinear quantification. In this paper, we employ proper orthogonal decomposition (POD) to remove this restriction and apply this viewpoint to establish a damage location method for beam-like structures. The targeted structure was first divided into the sections by designated characteristic points, and the POD was used to obtain an optimized approximation of nonlinear systems' trajectory. When comparing the nonlinearity degrees of the characteristic points in undamaged and damaged structures, the location was identifiable by finding positions of maximal change. Additional experiments were conducted to demonstrate the method's effectiveness and applicability by determining the crack location and the influence of crack depth. Given our findings, we hope that this method can be extended to other vibrating structures with underlying nonlinearities. (C) 2019 Elsevier Ltd. All rights reserved.