EFFECT OF VIBRATIONS ON STRESSES AROUND A SPOT WELDING

Abstract

on the topic of the effect of vibrations on stresses around a spot welding, rectangular plates of material M.S. were used for spot welding. A test specimen consisted of two such plates spot welded together and finished to a specific geometry to enable the constant stress amplitude to be applied on a reverse bending machine... Number of such test specimens were prepared under the same conditions of welding parameters. Spot welding induced thermal stresses in the test plates. The state of stress at each point on the plate was determined by the measurement of hardness at that point by micro hardness testing. The complete state of stress at each point on the specimen is thus known and then it is put on the reverse bending machine for the study of the effect of vibrations. Changes in hardness occurred as a result of applying load cycles. Number of such observations of the change of stress that took place with varying number of cycles applied were made. It is found that strain hardening phenomenon takes place with loss of ductility and test specimen fails in brittle fracture.