Description

Frederick Goodwin Lehman works on an experiment to determine methods for measuring stress on gusset plates. Original caption: "In the Structural Analysis Laboratory of the Department of Civil Engineering at Technology, a program of research is being directed by John B. Wilbur, Associate Professor of Structural Engineering, with the purpose of developing fairly simple methods of determining the correct stress distribution in the gusset plates used to join main members together in riveted and welded structures. Present design of gusset plates too often follows rule-of-thumb procedures, and when effort is made to analyze the stresses in such plates, it is generally very tedious and unsatisfactory. The development of methods more nearly accurate or more readily applicable, or both, is therefore extremely desirable. In our illustration, one part of the study is shown. Loads are being applied to a simple gusset plate, and the distribution of resulting stresses is being determined by means of electrical strain gauges affixed to the surface. The directions of the principal stresses are first found through a varnish technique devised at Technology by Greer Ellis, research assistant in the Department of Mechanical Engineering, and their magnitudes are then ascertained by means of the strain gauges, which were developed by Arthur C. Ruge, Assistant Professor of Engineering Seismology. Frederick G. Lehman, assistant in Civil Engineering, who is conducting this part of the work, is shown adjusting the apparatus." Used in: Technology Review, April 1942 Research Reports. Original credit line: MIT Photo.