Erosion Mechanics and Micromechanics Program.
Abstract
The objectives of this study were to provide the basic understanding of the particle impact phenomena which produce damage in IR windows in order to establish material development guidelines, to predict performance under anticipated operational conditions, to define failure conditions, to establish the technical base on which extrapolation into high velocity impact regimes can be carried out, and to extend the understanding of material behavior into the transitional regime between low velocity rain erosion processes important to IR and optical windows and the hypervelocity reentry conditions which are critical to reentry vehicle designs. A series of three dynamic particle impact analyses were carried out for PDA at California Research and Technology, Inc. using their WAVE-L computer program. A study of material fracture and micromechanics consideration led to an understanding of the material behavior associated with particle impact. Specific accomplishments of the study include a theoretical explanation of the Rochester and Brunton experimental observations of off-axis pressure peaking for water particle impact, the discovery of major tensile components of the three-dimensional stress field not predicted accurately by static Hertzian analyses, and the formulation of a combined micromechanics and macromechanics analysis technique associated with the flaw distribution characteristics of the material being analyzed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1977
- Accession Number
- ADA042656
Entities
People
- J. D. Buch