Abstract: A large damped structure which is developping with the advancement of space and aircraft industry and chemical industry, can effectively reduce and eliminate the random vibration with wide range frequencies and mechanical vibration with many resonant peaks. So there is a bright outlook for this new structure and new technique. But up to now, the research work in the aspect is still not perfect. Therefore, people are trying to find out a principle of structure design and a method of theoretical analysis which will offer a solid foundation for a wider employment of this technique. This paper theoretically and experimentally gives an account of our work in this respect.

Key words: A-TIG welding, metal vapor, numerical modeling