Effect of Curvature on Circumferential Tensile Strength of PE Pipes

doi:10.19491/j.issn.1001-9278.2020.10.007

Abstract

Abstract:

In this paper， a hoop tensile test method was adopted to detect the hoop tensile strength of high-density polyethyene （PE-HD） pipes， and the effect of the change of curvature caused by the deformation of the sample on the hoop tensile strength was investigated during the test. In the experiment， the optimized parallel tests were carried out to obtain accurate test data. After the collection of the huge amount of test data， the results indicated that for the PE-HD pipes with the same outer diameter， their hoop tensile strength decreased by 10 % with a reduction of the curvature of hoop tensile specimen under the test. Moreover， the effect of the variation law of curvature on the hoop tensile strength of PE-HD pipes was discussed.

Key words: high-density ethylene, pipe, wall thickness, hoop tensile strength, curvature

CLC Number:

TQ 325.1⁺2

PENG Jingang, ZHU Ruixia, FAN Yingkui, SUN Baozheng, CHENG Liang. Effect of Curvature on Circumferential Tensile Strength of PE Pipes[J]. China Plastics, 2020, 34(10): 37-43.

Figures/Tables 16

Fig.1. Sample for circumferential tensile strength test

Fig.2. Device for the hoop tensile test

Fig.3. Strain of the circumferential tensile test samples under the internal stress

规格	SDR26	SDR21	SDR17	SDR13.6	SDR11
dn160	111.17	104.84	97.51	88.50	78.15
dn200	139.16	131.16	121.78	110.83	97.88
dn315	213.01	201.06	186.30	169.10	149.57

Tab.1. Curvature radius of different specifications and SDR value

规格	SDR26	SDR21	SDR17	SDR13.6	SDR11
dn160	0.009 00	0.009 54	0.010 26	0.011 30	0.012 80
dn200	0.007 19	0.007 62	0.008 21	0.009 02	0.010 22
dn315	0.004 70	0.004 97	0.005 37	0.005 91	0.006 69

Tab.2. Curvature of different specifications and SDR value mm-1

规格	$σ$ /MPa
规格	试样1	试样2	试样3	试样4	试样5	$X -$	S
dn160SDR26	23.34	23.51	23.36	23.42	23.62	23.45	0.12
dn160SDR21	23.66	23.73	23.64	23.80	23.83	23.73	0.08
dn160SDR17	24.20	24.05	23.96	23.91	24.23	24.07	0.14
dn160SDR13.6	25.07	24.98	25.23	25.17	25.16	25.12	0.10
dn160SDR11	26.42	26.10	26.45	26.40	26.48	26.37	0.15

规格	$σ$ /MPa
规格	试样1	试样2	试样3	试样4	试样5	$X -$	S
dn160SDR26	23.34	23.51	23.36	23.42	23.62	23.45	0.12
dn160SDR21	23.66	23.73	23.64	23.80	23.83	23.73	0.08
dn160SDR17	24.20	24.05	23.96	23.91	24.23	24.07	0.14
dn160SDR13.6	25.07	24.98	25.23	25.17	25.16	25.12	0.10
dn160SDR11	26.42	26.10	26.45	26.40	26.48	26.37	0.15

Tab. 3. Circumferential tensile strength of dn160 pipes

规格	$σ$ /MPa
规格	试样1	试样2	试样3	试样4	试样5	$X -$	S
dn200SDR26	23.88	24.02	23.79	23.71	24.00	23.88	0.13
dn200SDR21	24.44	24.41	23.98	24.16	24.26	24.25	0.19
dn200SDR17	24.71	24.92	24.84	24.80	24.63	24.78	0.15
dn200SDR13.6	25.37	25.40	25.44	25.63	25.47	25.46	0.09
dn200SDR11	26.73	26.62	26.57	26.64	26.68	26.65	0.06

规格	$σ$ /MPa
规格	试样1	试样2	试样3	试样4	试样5	$X -$	S
dn200SDR26	23.88	24.02	23.79	23.71	24.00	23.88	0.13
dn200SDR21	24.44	24.41	23.98	24.16	24.26	24.25	0.19
dn200SDR17	24.71	24.92	24.84	24.80	24.63	24.78	0.15
dn200SDR13.6	25.37	25.40	25.44	25.63	25.47	25.46	0.09
dn200SDR11	26.73	26.62	26.57	26.64	26.68	26.65	0.06

Tab. 4. Circumferential tensile strength of dn200 pipes

规格	$σ$ /MPa
规格	试样1	试样2	试样3	试样4	试样5	$X -$	S
dn315SDR26	24.23	24.19	24.01	24.17	24.20	24.16	0.09
dn315SDR21	24.45	24.53	24.40	24.36	24.39	24.43	0.07
dn315SDR17	24.87	24.95	24.81	24.80	25.36	24.96	0.12
dn315SDR13.6	25.73	25.84	25.65	25.59	25.90	25.74	0.13
dn315SDR11	26.90	26.84	26.77	26.69	27.20	26.88	0.19

规格	$σ$ /MPa
规格	试样1	试样2	试样3	试样4	试样5	$X -$	S
dn315SDR26	24.23	24.19	24.01	24.17	24.20	24.16	0.09
dn315SDR21	24.45	24.53	24.40	24.36	24.39	24.43	0.07
dn315SDR17	24.87	24.95	24.81	24.80	25.36	24.96	0.12
dn315SDR13.6	25.73	25.84	25.65	25.59	25.90	25.74	0.13
dn315SDR11	26.90	26.84	26.77	26.69	27.20	26.88	0.19

Tab. 5. Circumferential tensile strength of dn315 pipes

规格	$σ$ /MPa
规格	SDR26	SDR21	SDR17	SDR13.6	SDR11
dn160	23.45	23.73	24.07	25.12	26.37
dn200	23.88	24.25	24.78	25.46	26.65
dn315	24.16	24.43	24.96	25.74	26.88

规格	$σ$ /MPa
规格	SDR26	SDR21	SDR17	SDR13.6	SDR11
dn160	23.45	23.73	24.07	25.12	26.37
dn200	23.88	24.25	24.78	25.46	26.65
dn315	24.16	24.43	24.96	25.74	26.88

Tab. 6. Circumferential tensile strength of different specifications and SDR

Fig.4. Trend graph of tensile strength and curvature of different specifications

Fig.5. Schematic diagram of PE production line

Fig.6. Dispersion schematic of carbon black with different compounding screw

Fig.7. Schematic diagram of the excessive plasticization pipe

Fig.8. Schematic diagram of corrugation of inner wall of the pipe

Fig. 9. Deformation of structure of circumferential tensile sample

Fig. 10. Schematic diagram of the position of the D?shaped block of the circumferential tensile sample

References 14

1	王占杰，赵艳，郭晶.中国塑料管道行业“十二·五”期间发展状况及“十三·五”期间发展建议［J］.中国塑料，2016，30（05）：1⁃7.
	WANG Z J， ZHAO Y， GUO J. Development Situation of China's Plastic Pipe Industry During the “Twelfth Five⁃Year” Period and Development Suggestions During the “Thirteenth Five⁃Year” Period ［J］ .China Plastics， 2016，30 （05）： 1⁃7.
2	乔慧敏.市政给水排水管道的类型与选择探析［J］.科技风，2019（12）：105⁃106.
	QIAO H M. Analysis of Types and Selection of Municipal Water Supply and Drainage Pipes ［J］ .Science and Technology， 2019 （12）： 105⁃106.
3	全国塑料制品标准化委员会. 《给水用聚乙烯（PE）管道系统第2部分：管材》［S］. 北京：中国标准出版社，2018.
4	American National Standards Institute. Polyvinyl Chloride （PVC） Pressure Pipe and Fabricated Fittings［S］. United States：American Water Works Association， 2016.
5	谢宁，何钰.用物理方法推导曲率半径公式［J］.教育教学论坛，2020（06）：276⁃277.
	XIE N， HE Y. Deduction of Curvature Radius Formula by Physical Method ［J］. Education and Teaching Forum， 2020 （06）： 276⁃277.
6	ASTM International. Standard Test Method for Apparent Hoop Tensile Strength of Plastic or Reinforced Plastic Pipe［S］. United States： ASTM International， 2016.
7	范英奎，朱瑞霞，彭金刚，等.PVC⁃UH管材壁厚对环向拉伸强度的影响［J］.中国塑料，2019，33（08）：38⁃43.
	FAN Y K， ZHU R X， PENG J G， et al. Effect of Wall Thickness of PVC⁃UH Pipe on Hoop Tensile Strength ［J］. China Plastics， 2019， 33 （08）： 38⁃43.
8	冯霖明.影响塑料制品拉伸试验结果的因素［J］.中国新技术新产品，2018（07）：33⁃34.
	FENG L M.Factors Affecting the Tensile Test Results of Plastic Products ［J］ .China New Technology and New Product， 2018 （07）：33⁃34.
9	周中.标准偏差在统计中的意义和计算［J］.川化，1998（01）：25⁃26.
	ZHOU Z. The Significance and Calculation of Standard Deviation in Statistics ［J］. Chuanhua， 1998 （01）： 25⁃26.
10	程红原，国旺，王卓.聚乙烯管材炭黑色母的研制和应用［J］.化学建材，2008（05）：1⁃3.
	CHENG H Y， GUO W， WANG Z. Development and Application of Carbon Black Masterbatch for Polyethylene Pipes ［J］. Chemical Building Materials， 2008 （05）： 1⁃3.
11	彭力争，宋玉峰.塑料给水管中炭黑分散性检测研究进展［J］.合成材料老化与应用，2020，49（02）：109+113
	PENG L Z， SONG Y F. Research Progress on the Detection of Carbon Black Dispersion in Plastic Water Pipes ［J］. Aging and Application of Synthetic Materials， 2020，49 （02）： 109+113.
12	贺盛喜，宋晓玲.转矩流变仪与差示扫描量热仪联用在研究PVC材料加工性能的应用［J］.中国氯碱，2016（12）：30⁃33.
	HE S X， SONG X L. Application of Torque Rheometer and Differential Scanning Calorimeter in Studying Processing Performance of PVC Materials ［J］ .China Chlor⁃Alkali， 2016 （12）： 30⁃33.
13	杜德鑫．关于单螺杆塑料挤出机的节能分析和设计［J］．机械设计与制造工程，2013，42（7）：59⁃62．
	DU D X. The Energy Saving Analysis and Design forP1astics Single—Screw Extruder［J］． Machine Design and Manufacturing Engineering，2013，42（7）：59⁃62．
14	何祝斌，苑世剑，查微微，等.管材环状试样拉伸变形的受力和变形分析［J］.金属学报，2008（04）：423⁃427.
	HE Z B， YUAN S J， CHA W W， et al. Stress and Deformation Analysis of Tensile Deformation of Ring Specimens of Pipes ［J］ .Acta Metallurgica Sinica， 2008 （04）： 423⁃427.

[1]	LI Zhengdian, SONG Le, LI Minghao, HE Xuetao, XIE Pengcheng, YANG Weimin. Design and experimental study of flexible manufacturing mould system for injection molding [J]. China Plastics, 2022, 36(7): 104-108.
[2]	PENG Jing, XIAO Da, WU Yingjiang, LI Bing, ZHANG Long, LI Zegang. Comparative analysis of Chinese and international standards for plastics structured⁃wall drainpipes [J]. China Plastics, 2022, 36(4): 135-141.
[3]	HE Yi, ZHAO Guanghui. Research progress in repairing and reinforcement of oil and gas pipeline with composites [J]. China Plastics, 2022, 36(4): 70-82.
[4]	YANG Xiaochun, YU Jing, ZHANG Qing. Effects of N⁃ethylpiperazinylphthalomide zinc on thermal stability of PVC [J]. China Plastics, 2022, 36(2): 125-130.
[5]	ZHANG Xuemin, HOU Lin, FENG Jinmao, YAO Zhongliang, ZHONG Mingqiang. Study on natural aging behavior of buried polyethylene water supply pipeline in service [J]. China Plastics, 2022, 36(2): 49-55.
[6]	WANG Zhenchao, ZHANG Ying, PENG Yijuan, YU Xi, ZHANG Qiuju. Research progress on reliability assessment methods of polyethylene pipes fusion joint [J]. China Plastics, 2022, 36(1): 148-159.
[7]	CAI Haokun, DONG Jian, JIANG Zhongyi. Effect of carbon black on physical properties of polyethylene pipes for water supply [J]. China Plastics, 2022, 36(1): 42-46.
[8]	ZHANG Yunpeng, LIU Xiangwei, WANG Zhiming, ZHANG Zhao, WANG Qingzhao. Design and manufacture of glass⁃fiber⁃reinforced PVC thermoplastic composite pipes for underground filling in coal mine [J]. China Plastics, 2022, 36(1): 61-66.
[9]	WANG Zhigang, YANG Bo, LI Zhi, PENG Guoping, JIANG Zaijia, LI Guanbao. Study on Correlation Between Process Defect and Mechanical Properties of Polyethylene Pipe Elector⁃fusion Joints [J]. China Plastics, 2021, 35(9): 64-68.
[10]	ZHAO Xingmin, ZHAO Jianping, YAN Jizhong. Photo⁃oxidation Aging Performance and Life Prediction for High⁃density Polyethylene Pipe [J]. China Plastics, 2021, 35(6): 33-39.
[11]	ZHONG Luohao, KUANG Tangqing, LAI Jiamei, LIU Hesheng, LAI Dewei. Effect of Molding Process on Wall Residual Thickness Distribution and Glass⁃fiber Orientation of Short⁃glass⁃fiber⁃reinforced Polypropylene Molded Pipes [J]. China Plastics, 2021, 35(5): 11-16.
[12]	HE Yintong, LIANG Jiaqi, LIU Lubin, XU Yue, WANG Kezhu, YU Hang, WANG Shuhui, XU Miaojun. Preparation and Applications of Water⁃resistant Flame⁃retardant Transparent Epoxy Resins [J]. China Plastics, 2021, 35(5): 6-10.
[13]	JIANG Ruitao, WU Zhifeng, WANG Zhiwei. Research on Structure of PE to Steel Transition [J]. China Plastics, 2021, 35(5): 86-91.
[14]	ZHAO Xingmin, ZHAO Jianping, YAN Jizhong. Study on Constitutive Model for Butt Fusion Welded Joint of High⁃density Polyethylene Pipe [J]. China Plastics, 2021, 35(4): 65-71.
[15]	SHI Jianfeng, HU Anqi, ZHENG Jinyang. Development Status of Technical Standards in Polyethylene Piping [J]. China Plastics, 2021, 35(3): 112-123.