中国塑料 ›› 2025, Vol. 39 ›› Issue (7): 49-55.DOI: 10.19491/j.issn.1001-9278.2025.07.009

• 加工与应用 • 上一篇    下一篇

循环载荷法评价聚乙烯管材料耐疲劳失效性能的研究

胡砚磊(), 孙晋, 胡法, 武志军, 李玉娥, 吴孝翰   

  1. 中石化(北京)化工研究院有限公司,北京 100013
  • 收稿日期:2024-12-23 出版日期:2025-07-26 发布日期:2025-07-22
  • 作者简介:胡砚磊(1992-),工程师,主要从事高分子材料及制品测试评价新方法的研究工作,huyl.bjhy@sinopec.com

Study on fatigue failure resistance of polyethylene pipe materials evaluated by cyclic loading method

HU Yanlei(), SUN Jin, HU Fa, WU Zhijun, LI Yue, WU Xiaohan   

  1. Sinopec (Beijing) Chemical Research Institute Co,Ltd,Beijing 100013,China
  • Received:2024-12-23 Online:2025-07-26 Published:2025-07-22

摘要:

采用循环载荷缺口圆棒(CRB)试验方法研究了聚乙烯(PE)管材料的耐疲劳失效性能,并考察了不同样品制备方式、样品尺寸、应力范围、频率、载荷比和温度等因素对材料失效结果的影响。结果表明,采用压塑制样的PE管材料在CRB试验中的耐疲劳性能优于管材挤出样品;随着样品直径的增加,断裂循环次数显著减少;应力范围增大也会导致断裂循环次数减少,并在应力范围达到16 MPa时出现脆韧转变现象;试验频率的提高使试样断裂循环次数减少;而载荷比的增加则导致样品断裂循环次数上升;温度升高会引起试样断裂循环次数的下降。

关键词: 聚乙烯管材料, 疲劳, 耐慢速裂纹增长, 循环载荷缺口圆棒

Abstract:

This study evaluated the fatigue resistance of polyethylene (PE) pipe materials using cracked round bar cyclic loading tests. A systematic investigation was conducted to assess the effects of manufacturing method (compression molding vs. extrusion), specimen geometry, loading parameters (stress range, frequency, load ratio), and temperature on fatigue performance. Results indicated that compression⁃molded specimens exhibited superior fatigue resistance compared to extruded pipes. Fatigue life was significantly influenced by test conditions: (1) increasing specimen diameter reduced fracture cycles, (2) higher stress ranges reduced fatigue life, with a brittle⁃ductile transition occurring at 16 MPa, (3) elevated frequencies accelerated failure, (4) increased load ratios improved fatigue resistance, and (5) higher temperatures reduced cycle counts. These findings provide critical insights for optimizing PE pipe design and performance under cyclic loading conditions.

Key words: polyethylene pipe materials, fatigue, slow crack growth, cyclic loading cracked round bar

中图分类号: