BLAST DAMAGE TO TREES-ISOLATED CONIFERS. REPORT TO THE TEST DIRECTOR
Abstract
Project 3.3, aiming at prediction of blast damage to forests from atomic explosions, sought to establish the following relationships for isolated coniferous trees: (1) Tree damage in terms of stem breakage, branch breakage, and defoliation in relation to peak overpressure and positive phase duration time; (2) deflection-time and strain-time functions for tree stems following arrival of shock wave. Blast damage to forests from atomic explosions is primarily a function of aerodynamic drag associated with particle velocity. Peak dynamic pressure is a more compatible parameter than peak overpressure for predicting blast damage to trees and other structures which have comparatively long periods and are susceptible to damage by aerodynamic drag. The lower limit of peak dynamic pressure for complete breakage of isolated conifers is estimated to be in the order of 0.7 psi when associated with 1-sec positive phase duration. This value of dynamic pressure corresponds to a sea level overpressure of 5.5 psi for Mach reflection. Some breakage will occur at lower peak dynamic pressures because of strength variations in tree stems. Natural forests or prepared forest stands can be instrumented economically to study blast damage from atomic explosions with no requirement for outside power or timing signals.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1953
- Accession Number
- AD0801308
Entities
People
- A. A. Brown
- F. M. Sauer
- R. K. Arnold
- W. E. Reifsnyder
- W. L. Fons