A survey of development in welding stress and distortion controlling in aerospace manufacturing engineering in china

摘要

Factors affecting welding stress and distortion and their relationship, concepts of internal and external restraints are discussed. Computer aided modelling, numerical analysis of welding stress and distortion and their experimental verification using high temperature Moire measurement are described. Progress made in solving welding stress and distortion problems is given. Physical and mechanical properties in terms of temperature are given for AMg6, 18-9 Ti austenitic stainless steels, TA6V and mild steel. A new method for in-process control of welding stress and distortion has been developed by BANITRI in China for aerospace applications such as jet engine cases of heat resistant materials and rocket fuel tanks in aluminum alloys. A dynamic Low Stress Non Distortion method (LSND) has been implemented. The formation of incompatible compressive plastic strain in the near arc zone is dynamically controlled by a localized moving tensile effect which is created using a spot heat sink following the arc. This dynamic method gives more flexibility in practical applications than the static LSND method for nonlinear and non-regular welds.