Evaluation of Roof Trusses, Phase II. Use of Frequency of Vibration to Determine Chord Tension.
NTIS: PB/84-166479 :58 pages
This report deals with efforts to develop a portable device suitable for underground use for the purpose of measuring the frequency of vibration of the horizontal chords of birmingham roof trusses. Four devices were investigated and evaluated. An approximate empirical expression developed from a mathematical analysis provides a means of converting the frequency into tension. The method appears to be effective in mines with shale roof but requires some modification for other roofs.
CP; Final Contract Report;
NTIS Accession No.
University of Pittsburgh