Fatigue life of PEEK poppet for deep-sea hydrothermal fluid sampling valve
WANG Hang-zhou1, QIN Hua-wei1, YANG Can-jun2, CHEN Ying1,2
(1. Institute of Machine and Electronic Engineering, Hangzhou Dianzi University, Hangzhou 310018, China;
2. State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027, China)
After analyzing the working cycles of the PEEK poppet of deep-sea hydrothermal sampling valves working in extreme temperature and pressure conditions, this work proposed an analytical method to predict the fatigue life of the PEEK poppet under varying working pressure with a maximum value of 70 MPa. The geometrical dimensions, stress concentration and loading styles of the PEEK poppet were comprehensively considered. By applying the traditional nominal stress method, the stress-fatigue life curve of the PEEK poppet during working cycles was obtained using the stress-fatigue life curve of the PEEK material. Then the fatigue life was estimated with thefatigue cumulative damage rule. A test rig was designed to imitate the sampling process, and the fatigue tests were performed on several poppets in the same manufacture series. The test results were consistent and agreed well with the analytical results. The fatigue life of the PEEK poppet is 7 cycles under the working condition, and the fatigue failure of the poppet accords with the fatigue cumulative damage rule．
［1］ GERMAN C R, PARSON L M. Distributions of hydrothermal activity along the Mid-Atlantic Ridge: interplay of magmatic and tectonic controls ［J］. Earth and Planetary Sciences Letters, 1998, 160(3/4): 327-341．
［2］ 杜同军,瞿世奎,任建国. 海底热液活动与海洋科学研究［J］. 青岛海洋大学学报, 2002, 32(4): 597-602．
DU Tong-jun, ZHAI Shi-kui, REN Jian-guo. Studies on the seafloor hydrothermal activity and ocean science ［J］. Journal of Ocean University of Qingdao, 2002, 32(4): 597-602．
［3］ LUPTON J E, BAKER E T, MASSOTH G J. Helium, heat, and the generation of hydrothermal event plumes at mid-ocean ridges ［J］. Earth and Planetary Sciences Letters, 1999, 171(3): 343-350．
［4］ CHEN Ying, WU Shi-jun, XIE Ying-jun, et al. A novel mechanical gas-tight sampler for hydrothermal fluids ［J］. IEEE Journal of Oceanic Engineering, 2007, 32(3): 603-608．
［5］ 刘伟,杨灿军,吴世军,等. 深海热液采样阀耐高压塑料阀芯研究［J］. 浙江大学学报：工学版, 2008, 42(2): 215-218．
LIU Wei, YANG Can-jun, WU Shi-jun, et al. Study on high pressure-resistant plastic poppet of deep-sea hydrothermal fluid sampling valve ［J］. Journal of Zhejiang University: Engineering Science, 2008, 42(2): 215-218．
［6］ Victrex. Victrex PEEK high performance polymers ［EB/OL］. (2009-03-10). http:∥www.victrex.com/literature_files/Material_Properties_Guide_en.pdf．
［7］ 姚卫星. 结构疲劳寿命分析［M］. 北京：国防工业出版社, 2003: 5-95．
［8］ 李舜酩. 机械疲劳与可靠性设计［M］. 北京：科学出版社, 2006: 11-95．
［9］ 徐灏,蔡春源,严隽琪,等. 机械设计手册［M］. 2版. 北京：机械工业出版社, 2003: 49-50．
［10］ 徐灏. 疲劳强度设计［M］. 北京：机械工业出版社, 1981: 67-75．
