Freytag, Norman A.
Resistance Welding Engineer, Metallurgical and Welding Research Laboratory, The Budd Co., Philadelphia, Pa.
Pages: 11 Published: Jan 1961
Principal strain directions as well as principal strain differences have been determined on a cross-section of a single lapped spot weld using photoelastic coating techniques in this preliminary study.
The highest stressed areas on the specimen investigated occur on the interface surface of the welded joint somewhat away from the forged area surrounding the spot weld within the range of loading investigated and not on the edge of this area as previously expected.
Due to the nature of the spot-weld tensile shear test, bending in the legs of the specimen tends to diminish with respect to the tensile load applied as load increases. This is indicated by a shift in the neutral axis toward the outer surface of the weld specimen.
Yielding on the interface surfaces of the spot-weld specimen occurred in a direction corresponding to the maximum shear-strain direction at that area.
At the particular section of the load-carrying leg that was studied, the effects of “funneling” the load from the entire cross-section of the leg down through the two spot welds were noticed.
Paper ID: STP44361S