Study On Adaptable Design Of Underwater Friction Stitch Welding Machine

Underwater friction stitch welding is a new type of solid-phase connection technology. Compared with other underwater connection technology, underwater friction stitch welding contains advantages as followed, such as insensitive to water depth, small welding deformation, good mechanical properties, high efficiency, etc. With global energy supply shortage, more and more attention focus on ocean. Ocean contains rich oil and natural gas resources, and our country pay much attention to the exploitation of marine resources, urgently needing advanced and reliable underwater connection technology. Therefore, the study of friction stitch welding has important engineering value and theoretical significance. Aiming at diversity of underwater tubular repair, this thesis focus on structure design, priority design and evaluation of adaptability of underwater friction stitch welding device.Firstly, the principle and process of friction stitch welding are described. On the foundation of requirement analysis and function analysis, open structure and close structure are proposed. The working principle and welding process of friction stitch welding machine are analyzed.Secondly, to get more structure schemes of friction stitch welding device, modules constitute the two structures are decomposed and redesigned. The important properties of new schemes are calculated, which provides data for the structure priority design.Once more, the concepts related to grey correlation method are described, and the detailed steps using grey correlation method to evaluate various schemes are introduced. Hierarchical relation of evaluation index is determined, the original data matrix is established, the grey correlation coefficient matrix is obtained after data processing, and then weight coefficients of different index are fixed to get grey correlation degree. Eventually, the structures with best performance are obtained for different repair position.And then, the detailed process of evaluation of adaptability based on set is described. The connotation and calculation method of adaptable factor are developed. The adaptability of the friction stitch welding machine indicates that the adaptable design for the device is effective and practical.Finally, friction stitch welding machine is manufactured. The synchronous of Z driver and clamping mechanism and gap adjuster are tested. Welding test for the pipe is carried out, which provides realistic basis for our later research.