Study on Mechanical Behavior of Plastic Pipe Reinforced Cross-Winding Steel Wire Subjected to Non-Axis Line Symmetric Surface Load on Soil

2015 ◽  
Vol 750 ◽  
pp. 251-260
Author(s):  
Xiang Li ◽  
Wei Feng Li ◽  
Liu Yun Xu
Keyword(s):  
Mechanical Behavior ◽  
Steel Wire ◽  
Element Model ◽  
Surface Load ◽  
Plastic Pipe ◽  
Steel Composite ◽  
Plastic Matrix ◽  
Symmetric Surface ◽  
Symmetric Load ◽  
Good Agreement

Plastic pipe reinforced by cross helically wound steel wires (PSP) is a new plastic-matrix steel composite pipe developed in China recently. To deeply understand the mechanical properties of buried PSPs, a finite element model of PSP subjected to non-axis symmetric load is proposed. The model is verified by replacing the parameters of PSP by those of steel pipe. A good agreement shows that the model can be used to analyze mechanical behavior of buried PSP. Finally, the influences of internal pressure, properties of soil, geometry parameters of PSP and magnitude of load, etc. are 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.

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.

Mechanical behavior analysis and structural improvement for the bracket arm of wrecker

2021 ◽  
pp. 1-14
Author(s):  
Chunlei Yu ◽  
Yingchao Bao ◽  
Chao Chen
Keyword(s):  
Mechanical Behavior ◽  
Working Condition ◽  
Stress Test ◽  
Element Model ◽  
Material Failure ◽  
Stress Distributions ◽  
Test Experiment ◽  
Structural Improvement ◽  
Maximum Stresses ◽  
Good Agreement

A finite element model (FEM) of the bracket arm of wrecker is developed and the mechanical behavior under six representative conditions is studied in this paper. Stress test experiment is carried out to validate the presented FEM. Comparison analyses show that results predicted from the FEM are in good agreement with those obtained from the test experiment. Moreover, the mechanical behavior analyses also give the danger working conditions for each component of the bracket arm. Based on the stress distributions under the danger working condition, structural improvement is conducted for the component which is prone to material failure. Mechanical behavior analyses of the improved structures are also carried out in this paper. Numerical analysis results show that the maximum stresses of each improved component of the bracket arm are all reduced to close or below the allowable stress. This indicted that the load bearing capacities of each component are improved effectively and meet the requirements of engineering applications.

Buckling Analysis of Plastic Pipe Reinforced by Cross-Winding Steel Wire Under Bending

2009 ◽  
Author(s):  
Xiang Li ◽  
Jinyang Zheng ◽  
Fengjian Shi ◽  
Yongquan Qin ◽  
Ping Xu
Keyword(s):  
Finite Element ◽  
Steel Wire ◽  
Element Model ◽  
Design Parameters ◽  
Geometrically Nonlinear ◽  
Buckling Mode ◽  
Element Analysis ◽  
Plastic Pipe ◽  
New Type ◽  
Composite Pipes

A plastic pipe reinforced by cross helically wound steel wires (PSP) has been developed rapidly in China as a new type of metal-plastics composite pipes. To deeply understand the mechanical properties of PSPs under pure bending, a four-layer analytical model is proposed based on Donnel theory. Additionally, a 3D finite element model (FEM) of PSPs under bending using an eigenvalue method is present. Good agreement between the theoretical results and finite element results is obtained, which shows that the proposed FEM can predict the buckling moments of PSPs. Further, A FEM of the PSP under bending is preformed by using the geometrically nonlinear finite element analysis (FEA). The buckling load is found by searching a bifurcation point on the geometrically nonlinear deformation path and the corresponding buckling mode is obtained from the eigenvalue analysis. Finally, the influence of the pipe lengths, design parameters and initial flaws on the buckling moment is analyzed using nonlinear FEA.

MODELING OF THE STRESS-STRAIN STATE OF A TRANSPORT TUNNEL UNDER LOAD AS A MEASURE TO REDUCE OPERATIONAL RISKS TO TRANSPORTATION FACILITIES

2020 ◽  
Vol 3 (8) ◽  
pp. 28-34
Author(s):  
N. V. IVANITSKAYA ◽  
◽  
A. K. BAYBULOV ◽  
M. V. SAFRONCHUK ◽  
◽  
...  
Keyword(s):  
Strain State ◽  
Moving Load ◽  
Element Model ◽  
Transport Infrastructure ◽  
Design Stage ◽  
Surface Load ◽  
Stress Strain ◽  
Stress Strain State ◽  
Operational Risks ◽  
Von Mises

In many countries economic policy has been paying increasing attention to the modernization and development of transport infrastructure as a measure of macroeconomic stimulation. Tunnels as an important component of transport infrastructure save a lot of logistical costs. It stimulates increasing freight and passenger traffic as well as the risks of the consequences of unforeseen overloads. The objective of the paper is to suggest the way to reduce operational risks of unforeseen moving load by modeling of the stress-strain state of a transport tunnel under growing load for different conditions and geophysical parameters. The article presents the results of a study of the stress-strain state (SSS) of a transport tunnel exposed to a mobile surface load. Numerical experiments carried out in the ANSYS software package made it possible to obtain diagrams showing the distribution of equivalent stresses (von Mises – stresses) according to the finite element model of the tunnel. The research results give grounds to assert that from external factors the stress state of the tunnel is mainly influenced by the distance to the moving load. The results obtained make it possible to predict in advance the parameters of the stress-strain state in the near-contour area of the tunnel and use the results in the subsequent design of underground facilities, as well as to increase their reliability and operational safety. This investigation gives an opportunity not only to reduce operational risks at the design stage, but to choose an optimal balance between investigation costs and benefits of safety usage period prolongation.

scholarly journals Fatigue Modeling and Numerical Analysis of Re-Filling Probe Hole of Friction Stir Spot Welded Joints in Aluminum Alloys

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Element Model ◽  
Plastic Strain Amplitude ◽  
Friction Stir ◽  
Probe Hole ◽  
Good Agreement

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.

Assessment of AASHTO Load-Spreading Method for Buried Culverts and Proposed Improvement

2021 ◽  
pp. 036119812110215
Author(s):  
Michael G. Katona
Keyword(s):  
Ad Hoc ◽  
Soil Depth ◽  
Free Field ◽  
Peak Stress ◽  
Element Model ◽  
Surface Load ◽  
Accuracy Evaluation ◽  
Simple Modification ◽  
Homogeneous Half Space ◽  
Order Of Magnitude

AASHTO’s ad hoc method (AAM) for predicting free-field soil stress under a rectangular loading area is a simple and very useful tool for the analysis of buried culverts subject to vehicular wheel loads. AAM assumes the surface load spreads with soil depth into an ever-increasing rectangular area whose dimensions are controlled by a constant spread angle θ usually taken as 30°, denoted as AAM-30°. Both simplified and comprehensive culvert analysis procedures utilize AAM predictions for adjusting pressure distributions acting on the culvert periphery. Also, AAM-30° is routinely used to determine the two-wheel soil interaction depth, in which the combined effect of both axial wheels need to be considered. To date, a thorough accuracy analysis of AAM-30° has not been published in the open literature. This paper provides a unique and rigorous evaluation of AAM-30° using an exact solution from an elasticity-based model (EBM) of a homogeneous half-space with rectangular surface load. One key discovery is the depth parameter called y*, which is the soil depth at which AAM-30° peak-stress prediction exactly matches the exact EBM solution. Moreover, it is shown that y* may be determined by a simple, yet accurate formula that only depends on the square root of the load area. However, the investigation reveals that AAM-30° significantly underestimates peak stress in the shallow-depth zone 0 <  y < ½ y* by as much as 31.3% of the applied surface pressure. As this is a large nonconservative error it cannot be ignored. Accordingly, a very simple modification is introduced called AAM-θ*, in which θ* is a spread angle that linearly increases to 30° at soil depth ½ y* and thereafter θ* remains constant at 30°. An accuracy evaluation of AAM-θ* reveals an order of magnitude increase in accuracy in which the small residual error is conservative, not nonconservative. The paper concludes with discussions on applying AAM-θ* to the analysis of buried culverts when using either simple or finite element model solution procedures.

Rigid-Plastic Impact of Single Angular Particles

2021 ◽  
Author(s):  
Sandeep Dhar
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Orientation Dependence ◽  
Particle Orientation ◽  
Rigid Plastic ◽  
Plastic Model ◽  
Model Predictions ◽  
Good Agreement ◽  
Angular Particles

The trajectory of an angular particle as it cuts a ductile target is, in general, complicated because of its dependence not only on particle shape, but also on particle orientation at the initial instant of impact. This orientation dependence has also made experimental measurement of impact parameters of single angular particles very difficult, resulting in a relatively small amount of available experimental data in the literature. The current work is focused on obtaining measurements of particle kinematics for comparison to rigid plastic model developed by Papini and Spelt. Fundamental mechanisms of material removal are identified, and measurements of rebound parameters and corresponding crater dimensions of single hardened steel particles launched against flat aluminium alloy targets are presented. Also a 2-D finite element model is developed and a dynamic analysis is performed to predict the erosion mechanism. Overall, a good agreement was found among the experimental results, rigid-plastic model predictions and finite element model predictions.

Investigation on Mechanical Properties of Fibreglass Reinforced Flexible Pipes Under Torsion

2018 ◽  
Author(s):  
Pan Fang ◽  
Yuxin Xu ◽  
Shuai Yuan ◽  
Yong Bai ◽  
Peng Cheng
Keyword(s):  
Mechanical Behavior ◽  
Torsion Angle ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Load Condition ◽  
Element Model ◽  
Flexible Pipe ◽  
Torsional Load ◽  
Flexible Pipes ◽  
The Impact

Fibreglass reinforced flexible pipe (FRFP) is regarded as a great alternative to many bonded flexible pipes in the field of oil or gas transportation in shallow water. This paper describes an analysis of the mechanical behavior of FRFP under torsion. The mechanical behavior of FRFP subjected to pure torsion was investigated by experimental, analytical and numerical methods. Firstly, this paper presents experimental studies of three 10-layer FRFP subjected to torsional load. Torque-torsion angle relations were recorded during this test. Then, a theoretical model based on three-dimensional (3D) anisotropic elasticity theory was proposed to study the mechanical behavior of FRFP. In addition, a finite element model (FEM) including reinforced layers and PE layers was used to simulate the torsional load condition in ABAQUS. Torque-torsion angle relations obtained from these three methods agree well with each other, which illustrates the accuracy and reliability of the analytical model and FEM. The impact of fibreglass winding angle, thickness of reinforced layers and radius-thickness ratio were also studied. Conclusions obtained from this research may be of great practicality to manufacturing engineers.

scholarly journals Probabilistic Assessment of the Safety of Main Cables for Long-Span Suspension Bridges considering Corrosion Effects

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Tian ◽  
Jiji Wang ◽  
Sugong Cao ◽  
Yuanli Chen ◽  
Luwei Li
Keyword(s):  
Probability Model ◽  
Steel Wire ◽  
Suspension Bridge ◽  
Element Model ◽  
Traffic Load ◽  
Suspension Bridges ◽  
Accelerated Corrosion ◽  
Long Span ◽  
Accelerated Corrosion Tests ◽  
Main Cables

This paper presents a reliability analysis to assess the safety of corroded main cables of a long-span suspension bridge. A multiscale probability model was established for the resistance of the main cables considering the length effect and the Daniels effect. Corrosion effects were considered in the wire scale by relating the test results from accelerated corrosion tests to the corrosion stages and in the cable scale by adopting a corrosion stage distribution of the main cable section in NCHRP Report 534. The load effects of temperature, wind load, and traffic load were obtained by solving a finite element model with inputs from in-service monitoring data. The so-obtained reliability index of the main cables reduces significantly after operation for over 50 years and falls below the design target value due to corrosion effects on the mechanical properties of the steel wire. Multiple measures should be taken to delay the corrosion effects and ensure the safety of the main cables in the design service life.

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