Illumination and Recording Accessories for High-Speed Photography to Study Dynamic Fracture of Brittle Solids
Abstract
Lightweight transparent armor structures are generally layered structures. The interface strengthand toughness play a critical role in deflecting or promoting branching of growing cracks and effectively absorbenergy. This helps in the development of failure resistant transparent armor alternatives to thick single layerdesigns. A mechanics-based research in this regard would require understanding how a dynamically growing crackinteracts with one or more interfaces. This in turn demands development of new experimental techniques toperform full-field mechanical measurements at high spatial and temporal resolutions. The PI has an ongoing AROgrant (# W911NF-16-1-0093) entitled Dynamics of Crack-Interface Interaction in Layered Transparencies: AnExperimental Investigation using Novel Optical Technique. The present Research Instrumentation (RI) grant (#W911NF-17-1-0355) was to acquire instrumentation in support of the above effort. The specific items acquiredwere: (i) a high energy LED pulsed laser light source, (ii) a high-intensity flash illumination system, (iii) a long focallength zoom lens and accessories. Item (i) minimizes blur in the recorded images in the vicinity of a rapidly growingcrack when used in conjunction with an ultrahigh-speed camera currently available in PI's lab. Item (ii) is a generalpurpose high energy solid-state flash lamps to replace/supplement aged ones currently used by the PI. Item (iii) isto perform paraxial imaging of fracture events at very high framing rates (> 1 million fps) from relatively longdistance yet achieve the necessary 'exposure' during photography.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 25, 2019
- Accession Number
- AD1084495
Entities
People
- Hareesh V. Tippur
Organizations
- Auburn University