Document Type
Thesis
Date of Award
5-31-1984
Degree Name
Master of Science in Mechanical Engineering - (M.S.)
Department
Mechanical Engineering
First Advisor
Herbert H. Spencer
Second Advisor
Richard A. Gaal
Third Advisor
Calman Pecker
Abstract
This thesis is concerned with the Southwell Plot method for measuring the critical load of thin-walled structural members whose postbuckling behavior is stable-symmetric.
In this method measurements are taken of the structure's central lateral deflection versus membrane compressive load P. Southwell's hypothesis is that (on a graph of δ/P vs. δ the reciprocal of the slope gives the critical load. He suggests that this is valid because the effect of the fundamental imperfection predominates as the load approaches the critical load+
The writer has examined Southwell's hypothesis in the presence of non-negligible (in fact dominant) higher mode imperfections. The writer has proposed different techniques to measure the critical load in those cases.
Extensive computer studies were made to predict the Effectiveness of the proposed techniques. Experimental tests have been conducted on columns purposely manufactured with known imperfections to check these proposed techniques. The experimental results have been analyzed using computerized statistical techniques. A beginning has been made with extending the numerical studies by nonlinear analysis.
The experimental results have indicated a trend that the Second RS Plot gave 5.8% better results than the Southwell plot and the other proposed plots.
Recommended Citation
Ranadive, Rajendra W., "Techniques for measuring critical loads in the presence of non-negligible higher mode imperfections" (1984). Theses. 3630.
https://digitalcommons.njit.edu/theses/3630
