Pre & Post Characterization of Armor Plate

We use many types of systems to characterize samples in their pre & post test conditions. For example, we’ve used CMMs to measure bore concentricity on Formula 1 engine blocks after stress tests, 3D scanning of air bags after 1,000 heat and freeze cycles, and x-rayed solder joints after salt water immersion cycling. This visual or numerically tangible characterization is critical for understanding how something responds under regular or extreme conditions and offers engineers key insights for improving their products.

This case study demonstrates the testing of a Level IV polyethylene & ceramic armor plate. The plate is rated for multi-hit capability. First, we CT scanned the plate in it’s new condition in our 450kv high resolution vault. Then, we shot the plate with four types of rounds – 9mm, .308 Winchester, 5.56, and 12 Gauge Slug. We re-scanned the sample and performed a comparative alignment to visualize differences.

Impact Zones, CT Slice Images

Below are images of each impact zone. The upper left quadrant of each image is the best visual indicator for severity.

Impact severity ranked most to least damage:

1. 12 Gauge Slug
2. .308 Winchester
3. 5.56 NATO M855
4. 9MM

3D CT Render of Spent Armor Plate

3D CT renderings are particularly useful for fast visualizations of complex objects. Because the part is so mangled it can be difficult to see all geometry or areas of interest simultaneously in a single planar slice view. The render below shows at location (1) no ceramic pieces have passed through the polyethylene layers. It also shows at location (2) details of the ballistic impact crater in the middle right.