中国塑料 ›› 2021, Vol. 35 ›› Issue (11): 91-96.DOI: 10.19491/j.issn.1001-9278.2021.11.014

• 加工与应用 • 上一篇    下一篇

PE100燃气管材的非线性蠕变行为及其本构模型研究

李茂东1, 李彦2, 杨波1, 王志刚1, 罗文波2,3()   

  1. 1.广州特种承压设备检测研究院,广州 510663
    2.湘潭大学土木工程与力学学院,湖南 湘潭 411105
    3.岩土力学与工程安全湖南省重点实验室,湖南 湘潭 411105
  • 收稿日期:2021-05-08 出版日期:2021-11-26 发布日期:2021-11-23
  • 基金资助:
    国家市场监督管理总局科技计划项目(2019MK159);国家自然科学基金项目(12072308)

Characterization and Constitutive Modelling of Nonlinear Creep of PE100 Grade Gas Pipe Material

LI Maodong1, LI Yan2, YANG Bo1, WANG Zhigang1, LUO Wenbo2,3()   

  1. 1.Guangzhou Special Pressure Equipment Inspection and Research Institute,Guangzhou 510663,China
    2.College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China
    3.Hunan Key Laboratory of Geomechanics and Engineering Safety,Xiangtan University,Xiangtan 411105,China
  • Received:2021-05-08 Online:2021-11-26 Published:2021-11-23
  • Contact: LUO Wenbo E-mail:luowenbo@xtu.edu.cn

摘要:

对PE100燃气管材开展不同应力水平(2.4~9.6 MPa)下的常温蠕变测试,结果显示应力不超过5.4 MPa时,材料的蠕变柔量与应力水平无关,呈现出线性黏弹性行为,当应力高于5.4 MPa时,材料发生非线性黏弹性蠕变。基于单积分型非线性黏弹性本构理论,采用Findley模型对蠕变行为进行分析,并与Struik经验模型进行比较。结果表明,Findley模型和Struik模型均能较好地描述PE100管材的蠕变行为,但对高应力下的非线性蠕变行为,Findley模型比Struik模型描述得更准确。

关键词: 聚乙烯, 燃气管道, 蠕变, 非线性黏弹性, 蠕变柔量, 本构模型

Abstract:

Polyethylene (PE) has been widely used in pressure pipeline engineering due to its excellent corrosion resistance. Long-term service behavior of a pipe is predominated by the creep property of its raw material. It is of great significance to study the creep behavior of PE at room temperature for the safety and integrity evaluation of PE pressure pipelines. In this paper, the room temperature creep tests of PE100 grade gas pipe material were conducted under various stresses ranging from 2.4 MPa to 9.6 MPa. The results indicated that there was a stress independency of creep comp?liance of the material when the stress does not exceed 5.4 MPa, indicating linear viscoelastic behavior. However, a stress dependency occurred and showed nonlinear viscoelastic creep when the applied stress was higher than 5.4 MPa. Based on the single integral nonlinear viscoelastic constitutive theory, the Findley model was used to analyze the creep behavior of PE100 grade gas pipe material by comparison with the Struik empirical model. It was found that both the Findley model and the Struik model well described the creep behavior of the pipe material, but the Findley model was more accurate than the Struik one for modeling the nonlinear creep behavior under high stresses.

Key words: polyethylene, gas pipe, creep, nonlinear viscoelasticity, creep compliance, constitutive model

中图分类号: