Establishing a Correlation Between Residual Stress and Natural Frequency of Vibration for Electron Beam Butt Weld of AISI 304 Stainless Steel

Residual stresses developed during complex multi-physics electron beam welding process are usually detrimental to the joint integrity. Moreover, the natural frequencies of vibration are reported to decrease with an increase in stress value. Not much literature is available on the study of the changes in natural frequency of vibration due to welding stresses. Moreover, such analysis is limited to mathematical modeling and conventional welding processes. Thus, in the present study, residual stresses of the welds corresponding to different heat inputs are measured experimentally using X-ray diffraction machine. A Polytec laser vibrometer-data acquisition system-LabView assembly is used to experimentally determine the natural frequencies of vibration. The novelty of this study lies with the establishment of a correlation between the measured welding stress and natural frequency of vibration. Additionally, the experimentally obtained residual stresses have also been validated through FEM results with satisfactory agreement. Furthermore, a noble approach of stress estimation using the natural frequencies is proposed and tested successfully.