Long-Term Stress Analysis of Plastic Pipe Reinforced by Cross-Winding Steel Wire

2008 ◽  
Author(s):  
Xiang Li ◽  
Jinyang Zheng ◽  
Yaxian Li ◽  
Ping Xu ◽  
Chunying Zheng ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Volume Fraction ◽  
Axial Strain ◽  
Steel Wire ◽  
Creep Behaviour ◽  
Viscoelastic Model ◽  
Time Dependent ◽  
Hoop Strain ◽  
Steel Wires ◽  
Plastic Pipe

Plastic pipe reinforced by cross helically wound steel wires (PSP) is a new type of metal-plastics composite pipe developed in China. Time-dependent properties of PSP are investigated theoretically and experimentally in this paper. Although the steel wire can carry most of the loading in a liner elastic way, the time dependent behavior shown in the PSP should be further analyzed and described. Based on the structural features of PSP and the viscoelastic behaviors of HDPE in matrix, a three layer viscoelastic model is proposed to calculate time-dependent elastic stresses and strains in the PSP subjected to internal pressure. The experimental results show that the hoop strain decreases slowly, while the axial strain increases by 0.16% in 14000 minutes at constant internal pressure. Good agreement between theoretical results and experimental data shows that the three layer viscoelastic model is able to predict the time-dependent relationship of stress and strain in PSP. The effects of volume fraction and winding angle of the steel wires on the creep behaviour of the PSP subjected to an internal pressure are discussed in the end.

Long-Term Stress Analysis of Plastic Pipe Reinforced by Cross-Wound Steel Wire

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Xiang Li ◽  
Jinyang Zheng ◽  
Yongquan Qin ◽  
Ping Xu
Keyword(s):  
Internal Pressure ◽  
Volume Fraction ◽  
Axial Strain ◽  
Steel Wire ◽  
Viscoelastic Model ◽  
Structural Features ◽  
Time Dependent ◽  
Hoop Strain ◽  
Steel Wires ◽  
Plastic Pipe

Plastic pipe reinforced by cross helically wound steel wires, namely, PSP, is a new plastic-matrix steel composite pipe developed in China recently, were theoretically and experimentally investigated herein. Although the steel wires carry most of the loading in a linear elastic way, time-dependent behavior was demonstrated in PSP, and was then the subject of further analysis and description. Based on the structural features of PSP and the viscoelastic behaviors of the matrix, a three-layer viscoelastic model was proposed to identify time-dependent elastic stresses and strains for PSP subjected to internal pressure. The experimental results showed that the hoop strain decreased slowly, while the axial strain increased by 0.16% in 14,000 min at constant internal pressure. Good agreement between theoretical results and experimental data demonstrated that the three-layer viscoelastic model was able to predict the time-dependent relationship of stress and strain. Finally, the effects of the steel-wire volume fraction and the winding angle on the creep behavior of PSPs subjected to an internal pressure were analyzed.

Analyses on the Short-Term Mechanical Properties of Plastic Pipe Reinforced by Cross Helically Wound Steel Wires

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Jinyang Zheng ◽  
Xiang Li ◽  
Ping Xu ◽  
Xiufeng Lin ◽  
Yaxian Li
Keyword(s):  
Mechanical Properties ◽  
Internal Pressure ◽  
Failure Modes ◽  
Steel Wire ◽  
Elastic Response ◽  
Exterior Surface ◽  
Steel Wires ◽  
Plastic Pipe ◽  
Steel Composite ◽  
Torque Values

Plastic pipe reinforced by cross helically wound steel wires, namely PSP, is a new plastic-matrix steel composite pipe developed in China recently. In order to understand the mechanical properties of PSP under internal pressure, a four-layer analytical model, which considers the torsion caused by the differences between the winding angles of the inner and outer steel wire layers, has been proposed using structural mechanics. The model includes an inner high density polyethylene (HDPE) layer, an inner steel wire layer, an outer steel wire layer, and an outer HDPE layer. To investigate the mechanical properties in inner and outer steel wire layers, the elastic parameters of the composite monolayer plate were deduced from the rectangle outside and circle inside model. During the elastic response of PSP subjected to internal pressure, the stresses and strains in four layers and pressures between the interfaces were obtained. Good agreement between theoretical results and experimental data was observed, which shows that the presented model can be employed to predict stresses, strains, and torsions in PSP. The failure modes and torque values between PSPs manufactured by two different methods were compared, and the influence of the change in the winding angle on the strain in the exterior surface was also discussed.

Analysis on the Mechanical Properties of the Plastic Pipe Reinforced by Cross Helically Winding Steel Wires (PSP) Under Internal Pressure

2015 ◽  
Author(s):  
Haichao Xiong ◽  
Yong Bai ◽  
Hongdong Qiao ◽  
Weidong Ruan
Keyword(s):  
Mechanical Properties ◽  
Internal Pressure ◽  
Mechanical Behavior ◽  
Steel Wire ◽  
Theoretical Method ◽  
Element Model ◽  
Equilibrium Equations ◽  
Steel Wires ◽  
Plastic Pipe ◽  
Anisotropic Elastic

This paper describes the analysis of the mechanical behavior of the plastic pipe reinforced by cross helically winding steel wires (PSP) under pure internal pressure. PSP is a new kind of composite pipe developed rapidly in China recently and it consists of an inner high-density polyethylene (HDPE) layer, several steel wire layers over wrapping the liner and an outer polyethylene coating. To investigate the mechanical properties of steel wire layers, the elastic parameters of the composite monolayer plate are considered as transverse isotropic and derived based on Halpin-Tsai Equations. The stress and strain functions of each layers are obtained using anisotropic elastic mechanical theory and the unknown constants are determined by equilibrium equations and interface conditions. Using ABAQUS, a finite element model (FEM) is established to study the mechanical behavior and failure mode. Results derived from the theoretical method and FEM are presented and compared. Simplified engineering formula of burst pressure is also obtained. The effect of winding angle on PSP is also discussed by parametric analysis. Values of burst capacity predicted from the theoretical method, FEM and simplified engineering formula are in great agreement with the experimental results.

Failure Analysis of Plastic Pipe Reinforced by Cross Helically Wound Steel Wire Subjected to Internal Pressure and Bending Load

2016 ◽  
Author(s):  
Jie Zhang ◽  
Jianfeng Shi ◽  
Jinyang Zheng
Keyword(s):  
Internal Pressure ◽  
Steel Wire ◽  
Operating Conditions ◽  
Combined Loading ◽  
Design Parameters ◽  
Fe Model ◽  
Plastic Pipe ◽  
Bending Load ◽  
Calculation Results ◽  
Bending Loads

Plastic pipe reinforced by cross helically wound steel wire (PSP) has been widely used in the transportation of petroleum, natural gas, municipal water, etc. In some serious occasions, PSP suffers from bending load caused by operating conditions such as ocean wave, pipeline laying and geological sedimentation, besides internal pressure. Thus, to understand the strength of PSP under the complex loads is crucial for ensuring safety. In this study, a finite element (FE) model of PSP was proposed by taking both internal pressure and bending load into consideration. By gradually increasing the bending load, the strength of PSP was obtained by taking the break of steel wires as the failure criterion. Then, combined loading tests were conducted to verify the proposed model. The results show that the applied bending loads bear a nonlinear relationship with the increasing deformation. By comparing experimental results and FE model calculation results, good agreement was obtained. Based on the verified FE model, the limit bending load and the effects of design parameters and internal pressure on the strength of PSP were discussed.

Preparation of Electron Transparent Metal-Matrix Composites

1968 ◽  
Vol 26 ◽  
pp. 334-335 ◽  
Author(s):  
M. R. Pinnel ◽  
A. Lawley
Keyword(s):  
Stainless Steel ◽  
Load Transfer ◽  
Volume Fraction ◽  
Steel Wire ◽  
Initial Step ◽  
Interfacial Region ◽  
Matrix Composites ◽  
Specific Test ◽  
The Matrix ◽  
The One

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.

scholarly journals Application of Polydioxanone Sutures in the Nuss Procedure

2021 ◽  
Author(s):  
Yimin Xie ◽  
Jinbo Ning
Keyword(s):  
Surgical Repair ◽  
Steel Wire ◽  
The Other ◽  
Risk Indicators ◽  
Nuss Procedure ◽  
Level Of Evidence ◽  
Wire Breakage ◽  
Steel Wires ◽  
Duration Of Operation

Abstract Background/Purpose The Nuss procedure is the most common surgical repair for pectus excavatum (PE). Surgical steel wires are used in some modifications of the Nuss procedure to attach one or both ends of a support bar to the ribs. During follow-up, wire breakage was found in some cases. Patients with wire breakage may undergo prolonged bar removal surgery and may be exposed to excessive radiation.In this study, we had a series of patients who received polydioxanone suture (PDS) fixations instead of steel wires. This retrospective study was conducted to explore the differences between these two fixation materials in the incidence of related complications and efficacies. Furthermore, we attempted to observe whether the two materials lead to similar surgical efficacy in the Nuss procedure, whether they have divergent effects on the bar removal surgery, and whether PDS can reduce the risks due to steel wire breakage as expected. Methods We retrospectively studied PDS and surgical steel wires as fixation materials for the Nuss procedure in children with congenital PE and reviewed the outcomes and complications. A total of 75 children who had undergone Nuss procedure repairs and bar removals from January 2013 to December 2019 were recruited to participate in this study. They were divided into three groups: the PDS group, the unbroken wire (UBW) group, and the broken wire (BW) group, according to the fixation materials and whether the wires had broken or not. Moreover, we selected the duration of operation (DO), intraoperative blood loss (BL), bar displacement (BD), postoperative pain score (PPS), and incision infection as the risk indicators and the postrepair Haller index (HI) as the effectiveness indicator. These indicators were statistically compared to determine whether there were differences among the three groups. Results One BD occurred in the PDS and BW groups while none took place in the UBW group. No incision infection was found in any of the groups. The PDS group had the shortest DO, while the DO in the UBW group was shorter than that in the BW group (p < 0.05). BL in the PDS group was less than that in the other two groups (p < 0.05). Additionally, no difference was observed in BL between the BW and UBW groups (p > 0.05). The PPS of the PDS group was less than that of the BW group (p < 0.05), whereas no differences were found between the other two groups. No statistical difference emerged in HI among the groups (p > 0.05). Conclusion PDS fixation results in a similar repair outcome and shows certain advantages in the DO, BL, and PPS; also, PDSs are safe and effective in the Nuss procedure. Level of evidence Level III.

Very thin torispherical pressure vessel ends under internal pressure: Test procedure and typical results

1981 ◽  
Vol 16 (3) ◽  
pp. 171-186 ◽  
Author(s):  
P Stanley ◽  
T D Campbell
Keyword(s):  
Stainless Steel ◽  
Internal Pressure ◽  
Elastic Stress ◽  
Test Procedure ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Test Installation ◽  
Stress Indices ◽  
Pressure Test ◽  
Strain Data

Very thin cylindrical pressure vessels with torispherical end-closures have been tested under internal pressure until buckles developed in the knuckles of the ends. These were prototype vessels in an austenitic stainless steel. The preparation of the ends and the closed test vessels is outlined, and the instrumentation, test installation, and test procedure are described. Results are given and discussed for three typical ends (diameters 54, 81, and 108in.; thickness to diameter ratios 0.00237, 0.00158, and 0.00119). These include measured thickness and curvature distributions, strain data and the derived elastic stress indices, and pole deflection measurements. Some details of the observed time-dependent plasticity (or ‘cold creep’) are given. Details of two types of buckle that developed eventually in the vessel ends are also reported.

Application of a Viscoelastic Model for Polyester Mooring

2010 ◽  
Author(s):  
J. W. Kim ◽  
J. H. Kyoung ◽  
A. Sablok
Keyword(s):  
Material Properties ◽  
Viscoelastic Model ◽  
Practical Method ◽  
Time Dependent ◽  
Mooring Line ◽  
New Model ◽  
Global Performance ◽  
Excitation Period ◽  
Linear Viscoelastic ◽  
Floating Platforms

A new practical method to simulate time-dependent material properties of polyester mooring line is proposed. The time-dependent material properties of polyester rope are modeled with a standard linear solid (SLS) model, which is one of the simplest forms of a linear viscoelastic model. The viscoelastic model simulates most of the mechanical properties of polyester rope such as creep, strain-stress hysteresis and excitation period-dependent stiffness. The strain rate-stress relation of the SLS model has been re-formulated to a stretch-tension relation, which is more suitable for implementation into global performance and mooring analyses tools for floating platforms. The new model has been implemented to a time-domain global performance analysis software and applied to simulate motion of a spar platform with chain-polyester-chain mooring system. The new model provides accurate platform offset without any approximation on the mean environmental load and can simulate the transient effect due to the loss of a mooring line during storm conditions, which has not been possible to simulate using existing dual-stiffness models.

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