Buckling of Stiffened Panels and Its Mitigation

The increased use of thin plates, like in ships for high-speed operation, results in significantly increased distortion. In-process control of welding distortion is more desirable than postwelding rectification from the point of manufacturing efficiency. This can be achieved by suitably designing and also implementing one or more of the distortion control measures as is suitable for a particular manufacturing situation. In this study, an investigation on buckling phenomenon in fabrication of stiffened panels was carried out. Analytical formulae were used to calculate the weld-induced compressive stresses. Critical buckling stresses considering appropriate buckling coefficient for typical stiffened panels as used in shipbuilding practice were calculated. The predictions from these analytical tools were compared with experimental observations. The experimental results compared fairly well with those of the calculated ones. In the present study the panel design aspect as well as thermomechanical tensioning scheme were studied with regard to buckling mitigation. It was observed that when choosing suitable stiffener spacing in conjunction with plate thickness, buckling distortion can be significantly reduced. Distortion mitigation through thermomechanical tensioning was also found to an effective yet simple-to-implement method of buckling distortion control. However, further investigation is necessary toward fully establishing the method of thermomechanical tensioning. Once this method is established, this pretensioning technique can be applied as an active in-process control method to avoid buckling distortion in stiffened panels.