Damage analysis of PE gas pipes under point loading

doi:10.19491/j.issn.1001-9278.2024.03.012

Abstract

Abstract:

The elasticity and yield parameters of PE were determined through a uniaxial tensile experiment. A pipe⁃soil finite element model under a point load was established to study the point⁃loading mechanical response of buried PE gas pipes， and the effects of point⁃loading dimension， pipe internal pressure， and pipe diameter were analyzed. Based on the DFDI （ductile failure damage indicator） model and combined with the finite element simulation results， quantitative damage calculations were carried out for PE pipes under a point load. The results indicated that the point load increased the pipe damage when compared to the damage results of the pipe without a point load. The pipe damage shows a great change with a variation of the internal pressure of the pipe. There is little effect on the PE pipe damage with a small change in the pipe diameter， and the damage values under each pipe diameter are relatively close to each other.

Key words: polyethylene, gas piping, point load, ductile failure damage indicator model, pipe damage

CLC Number:

TQ325.1⁺2

PU Qiang, HE Xia, WANG Guorong, HU Gang. Damage analysis of PE gas pipes under point loading[J]. China Plastics, 2024, 38(3): 67-72.

Figures/Tables 17

Fig.1. Point loads acting on the lower part of the pipe

塑性应力/MPa	塑性应变	塑性应力/MPa	塑性应变
7.42	0	13.81	0.097 27
9.41	0.023 74	14.67	0.126 95
10.02	0.030 3	15.1	0.158 8
10.35	0.050 7	15.35	0.189 39
12.89	0.065 08	15.53	0.220 03

Tab.1. Plasticity parameters of PE materials.

Fig.2. Schematic diagram of buried gas PE pipe under point load

Fig.3. Model boundary condition settings

Fig.4. Stress cloud of PE pipe with the point load at junction

Fig.5. Local stress cloud of PE pipe at junction against point load dimension

Fig.6. Mises stress variation curve of PE pipe along the axial direction against point load dimension

Fig.7. The strain variation curve of PE pipe along the axial direction against point load dimension

Fig.8. The stress cloud of PE pipe at the point load location against the internal pressure of the pipe

Fig.9. Mises stress variation curve of PE pipe along the axial direction against the internal pressure of the pipe

Fig.10. The strain variation curve of PE pipe along the axial direction against the internal pressure of the pipe

Fig.11. Local stress cloud of PE pipe at point load against pipe diameter

Fig.12. The Mises stress variation curve along the axis of PE pipe against pipe diameter

Fig.13. The strain variation curve along the axis of PE pipe for against pipe diameter

Fig.14. The damage of PE pipe against point load dimension

Fig.15. The damage of PE pipe against the internal pressure of the pipe

Fig.16. The damage of PE pipe against the diameter of the pipe

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