关键词: 低温收缩率, 应变片, 玻璃纤维增强塑料

Abstract: Abstract： An experimental system based on a twostage GM cryocooler was built to measure the thermal contraction from 15K to 293 K. The thermal contraction of the material at low temperature was measured by using the strain gauge method. The effects of variation of the resistance and gage factor (Ks) of karma foil strain gauge at low temperature on the measurement were analyzed and eliminated. The experimental thermal contraction of 304 stainless steel was first measured and compared with standard data to verify the reliability of the measurement and to obtain the correction coefficient (η′) of Ks at different temperatures. Then, the thermal contraction of Al6061T6 was measured and compared with standard data, and the maximum deviation is -4.8%, which proved that η′ was reasonable. Finally, the transversal and longitudinal thermal contraction of GFRP (glass fiber weight content of 70%) was measured at different temperatures. The experimental results show that the transversal thermal contraction of GFRP is approximately 1.12 times of the longitudinal thermal contraction in the same temperature range.

Key words: Key words： cryogenic thermal contraction, strain gauge, glass fiber reinforced plastic (GFRP)