1. Ultrasonics Baseline Free Impact Location
Sahithi Chatradi

2. Motivation
Impacts can cause significant and hard to detect disbonding damage, potentially leading to catastrophic failure if left undetected.

3. Background
TDOA systems compare the time of arrival of a signal at multiple sensors having known locations to evaluate the location of a source.
Requires baseline knowledge of the wave propagation velocity

4. Algorithm
Based on TDOA Technique
Matlab Script based on Algorithm.

5. Simulation
Given signal speed, times of arrival were calculated at the sensor locations.
The algorithm was tested with multiple sensor geometries and impact velocities

6. Fig. 5 – Typical experimental setup
Performed on 6061-T651 aluminum plates measuring x 0.30 m with thicknesses of m, and m.
Avoiding having 3 collinear sensors
Sensors- Lead Zirconate Titanate (PZT) piezoceramic

7. Future Work
The well-established properties of strain waves distorting and attenuating as they propagate are a potential source of errors
Identifying alternative signal markers or compensating for this distortion and attenuation could improve the accuracy of the system in real application.

8. Questions?