Fiber Optic Laser Vibrometer for Research on Material Damage Evolution
Abstract
The identification of defects produced during manufacturing and use of a material system rely on the ability to collect data. In particular, it relies on Nondestructive Evaluation (NDE) methods to obtain the data in a way that is not detrimental to the material in any way to ensure safe component use after inspection. Where possible, the use of these techniques during the manufacturing process or during service use of components is preferred as it minimizes downtime. Currently, limitations exist for such techniques when monitoring components used in extreme environments such as elevated temperatures as many sensor systems are not designed for these conditions. Additionally, dynamic systems such as engine turbines subjected to high velocity rotation, vibrations, and temperatures are impossible to directly instrument with sensors as direct contact can alter the response of the system and make it difficult to accurately assess the material. Application of NDE methods in manufacturing processes is similarly challenge as a result of high temperatures, moving parts, and minimal access space that exist in some form in all manufacturing methods. The acquisition of a Fiber Optic Laser Vibrometer will allow for the NDE monitoring of such systems with the Acoustic Emission (AE) NDE technique to detect defects and damage during material use. This technique is based on the concept that a material will release energy as it fails resulting in surface vibrations which can be detected by a sensor. This method is a passive technique that uses low energy consumption to detect damage and traditionally requires the sensor to be in contact with the sample. The implementation of the Laser system (LAE) will expand the material systems and loading methods that can be monitored. The system will be used to detect defects that are produced during additive manufacturing (AM) to allow for feedback to alter the build parameters to correct for the defect detected or to halt the build and begin again reducing material waste and manufacturing time while ensuring quality. The benefit of the LAE system is that it can be used to monitor for defects in metal, polymer, or even composite manufacturing including additive manufacturing processes. In addition, the LAE system will be used to probe material response to external loads to gain understanding of how a material will initiate and grow damage and determine what leads to catastrophic failure. This information can them be leveraged to detect and track damage evolution in material systems subjected to load schemes, such as dynamic or high temperature, that historically have proven difficult to monitor directly. The acquisition of the laser vibrometer will pave the way for development of improved manufacturing processes, material understanding, and component life predictions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2021
- Source ID
- W911NF2110035
Entities
People
- Brian Wisner
Organizations
- Army Contracting Command
- Ohio University
- United States Army