Abstract: It has high actual application value for the TiNiFe Shape Memory Alloy(SMA)tube tie-in using in the inaviation area to research the quantitative relationship of the TiNiFe SMA tube tie-in clasp stress with different wall thicknesses along with time. Basing on the dynamics modeling and the formula calculation of the TiNiFe SMA, this paper accomplishes the calculation simulation of the TiNiFe SMA tube tie-in clasp stress during the calefactive process taking use of computer software programming, and gaines the simulation curve that describes the TiNiFe SMA tube tie-in clasp stress in the calefactive state along with time. The tube tie-in wall thickness’s effect on the tube tie-in clasp stress is emphatically researched and validated through the actual experiment, and it is found that the calefactive changing process is very short and clasp stress produced by tube tie-in with wall thickness less than 2.5 mm almost linearly increases along with the wall thickness increasing.

Key words: shape memory alloy, tie-in clasp stress, TiNiFe