阴APP导航

Designs for ships and other large structures are making use of thinner steel plate materials to reduce weight and reduce material costs. Welding practices developed for thicker plate can result in significant buckling distortion when applied to thin-plate structures. This out-of-plane distortion can be particularly significant in complex structures where thin and thick plate sections are joined together. Buckling distortion can significantly increase fabrication cost and reduce production throughput due to the increased time to straighten, fit, and weld distorted structures. EWI has conducted a series of studies to develop techniques to predict and control distortion in large stiffened thin panels. This paper reports the results of these studies and describes innovative technologies to control buckling distortion in stiffened thin panels.

Computer modeling tools were developed to predict conditions which will result in buckling distortion, and to guide the development of distortion control strategies. Control of welding distortion for thin structures requires control of each welding operation from butt-welding of plates through to structure assembly. Best practices involve improving fitting practice, increasing restraint during each welding operation, controlling sequence, and minimizing welding heat input. Practical methods to achieve these best practices are described in this paper. Additionally, emerging technologies are described to prevent distortion in thin plate structures. These include innovative welding processes such as Friction Stir Welding and Laser Hybrid Arc Welding. An active buckling suppression approach, known as Transient Thermal Tensioning, is also described in which controlled heating patterns are applied to structures during welding to counteract the weld shrinkage stresses. This technique has been demonstrated to effectively suppress buckling distortion in stiffened panels used for ship construction.