Cumulative Damage Plaster Tests.
Abstract
The National Environmental Policy Act (NEPA) of 1969 requires the United States Air Force (USAF) to assess the environmental impacts of its operations. One such impact is the potential for cumulative structural damage from sonic boom exposures. Previous investigations of sonic boom structural damage have not ruled out the possibility of cumulative damage. Experiments on plaster walls tested the potential for cumulative damage resulting from multiple sonic boom exposures. Three measures of damage were used in this study: number of cracks, total crack length, and total crack area. New terminology is introduced to define the nature of the observed damage. When repetitive sonic booms cause the damage rate to increase with increasing numbers of booms, the damage is described as cumulative damage. hen the repetitive sonic booms result in a constant or decreasing damage rate, the damage is referred to as progressive damage. The observed cracking of the plaster surface in all test articles was minimal. The sonic boom induced plaster stresses were approximately one-third of the estimated stresses from environmental factors. The results of these and previous tests suggest that damage to plaster from sonic booms is a result of combined stresses of sonic booms with environmental stresses. (MM)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 12, 1993
- Accession Number
- ADA294912
Entities
People
- Alex See
- Jerold M. Haber
Organizations
- BBN Technologies