Integration of Signal Analysis Suite and Field-Portable Matrix Laser Doppler Vibrometer (MXLDV) for Composite NDE

ABSTRACT: This proposal seeks to advance Composite Defect Resonance Imaging by Vibration Excitation (CDRIVE) based on development of an automated data processing framework for integration with a newly developed high-speed Matrix Laser Vibrometer (MLV). The MLV, developed under an earlier program, provides, for the first time, an instrument for instant capture of 2D velocity images which depict the full-field temporal evolution of structural vibrations. The capabilities of the MLV, together with the interdependence of the excitation and signal processing strategy is critical to the overall CDRIVE methodology. While the MLV offers a unique hardware platform for CDRIVE, its future success depends upon development of systematic strategy aimed at defect detection with high probability and low false alarm rates. This proposal includes a comparative study which aims to establish these requirements based on a determination of the current scope of application, identification of the major technical limitations and, where possible, implementation of hardware and/or analytical solutions which address these limitations. A further goal of this proposal is to determine to what extent existing strategies or analyses may be adapted and incorporated to extend the current detection capabilities of CDRIVE. The results of this effort will be integrated under a CDRIVE operating system configured, as far as possible, for autonomous data collection, processing and review. BENEFIT: The NDI system, together with the core MLV technology developed under this program, represents an innovative development which will enhance the practicality of LDV for structural analysis. Numerous industries (automotive, aerospace, medical, musical instruments, and computer electronics) employ LDV for modal vibration analyses and structural diagnostics. In addition to modal analysis, the MLV would target the market represented by nondestructive testing in the marine, aviation and space industries and, in particular, the nondestructive inspection in manufacture and maintenance of deployed military vessels. Many types of military conventional and composite structures and vehicles can benefit from a systematic method to test for damage over large areas. The potential market is substantial. For example, the National Institute of Standards and Technology (NIST) estimated that the overall cost of damage detection and repair in the United States is 4.2% of the Gross National Product (GNP) or $290 billion in 1996. It is estimated that damage costs are $4 billion annually for military aircraft systems and $9 billion annually for commercial and private aircraft. The proposed MLV can also be used as a diagnostic tool for civil engineering and aging structures requiring inspection of bridges, oil, gas or water tanks, as well as walls of a building affected by catastrophic events (earthquake, tornado, etc.).