Collaborative Research: Novel NDE/SHM Approach Based on Highly Nonlinear Dynamics

California Institute Of Technology, Pasadena CA

Investigators

Abstract

This research will develop an experimental research program to create a new paradigm for Non Destructive Evaluation and Structural Health Monitoring (NDE/SHM) of materials and structures based on Highly Nonlinear Solitary Waves (HNSWs). The proposed research leverages on the tunability provided by highly nonlinear systems to open up a new field of theoretical and experimental investigations aimed at: a) understanding the coupling between a highly nonlinear oscillators and linear structures; b) detecting defects across scales: from the micro- to the macro-scopic level; c) evaluating applied stress in a given system; d) characterizing the mechanical properties of materials tailoring the pulse properties during propagation (inverse approach) aided by numerical modeling, and e) designing new, and therefore patentable, actuators/sensors technology for stress wave generation and detection. In the last two decades researches and applications of elastic stress waves (both in the sonic and ultrasonic range) for NDE/SHM have thrived owing to their capability of assessing the elastic properties of materials and the presence of damage. The recent discovery and development of the highly nonlinear wave theory and its numerical and experimental validation offer a new tool to the NDE/SHM community. The soundness of engineering systems is essential to avoid catastrophic failures that may be accompanied by severe consequences for the environment, can lead to the loss of human life, and produce tonnage of demolition waste. It is therefore of paramount importance to the nation?s sustainability, economy growth and safety that NDE/SHM, to be able to accurately detect defects at early stages or to characterize the mechanical properties of a given structure. With the proposed research we plan to delve in the fundamental understanding of highly nonlinear waves coupling with materials and structures, offering a direct opportunity to transfer the technology in viable commercial applications much improved over the state-of-the-art actuating/sensing technology for NDE/SHM. The work builds on complementary expertise at the University of Pittsburgh and the California Institute of Technology Caltech and will establish a solid research collaboration between the two institutions. The program will train graduate and undergraduate student to a new approach to sustainable engineering solutions.