Performance of large-diameter honeycomb-design HDPE pipe under a highway embankment

2000 ◽  
Vol 37 (5) ◽  
pp. 1099-1108 ◽  
Author(s):  
Shad M Sargand ◽  
Teruhisa Masada
Keyword(s):  
Finite Element ◽  
Large Diameter ◽  
Earth Pressure ◽  
Field Performance ◽  
Computer Code ◽  
Short Wave ◽  
Pipe Material ◽  
Linear Variable Displacement Transducer ◽  
Hdpe Pipe ◽  
Highway Embankment

This paper presents field performance data on a 1.07 m (42 in.) diameter, honeycomb (HC) design HDPE pipe which is buried under 15.85 m (52 ft) of fill at a highway construction site in Ohio. The pipe was instrumented with six biaxial strain gages to monitor strains during initial backfilling and earth-pressure cells for measuring load for about 1 year. A portable linear variable displacement transducer device was used to detect changes in vertical and horizontal diameters at mid-length sections. The pipe performance has been monitored for 386 days. The vertical and horizontal deflections of the test pipe stabilized at –10% and +3%, respectively. The pipe exhibited localized short-wave deformations and inner wall tearing at springline due to combined actions from bending and ring compression. Elastic solutions of Burns and Richard and a finite element computer code CANDE-89 were applied with long-term moduli specified for the pipe material to evaluate their analytical results in relation to the measured field pipe performance.Key words: field performance, plastic pipe, highway embankment, deep burial, finite element.

Rational Stress Limits and Load Factors for Finite Element Analyses in Pipeline Applications: Part III — Elastic-Plastic Load Factor Development

2016 ◽  
Author(s):  
Rhett Dotson ◽  
Chris Alexander ◽  
Ashwin Iyer ◽  
Al Gourlie ◽  
Richard Kania
Keyword(s):  
Finite Element ◽  
Case Studies ◽  
Large Diameter ◽  
Load Factor ◽  
Pipe Material ◽  
Line Pipe ◽  
Elastic Plastic ◽  
First Case ◽  
Load Factors

In this paper, a methodology is presented to develop load factors for use in elastic-plastic assessments of pipelines and their components. The load factors are based on the pipe material properties and the ASME pipeline code’s design margin for the service and location of the pipeline installation [1, 2]. These codes are recognized by 49 CFR 192 and 195 [3, 4]. Minimum required load factors for internal pressure loads can be derived analytically based on design equations from the ASME B31 piping codes and minimum material requirements for API 5L line pipe [6]. Once the load factor is established for a particular case, the elastic-plastic methodology may be used in the Finite Element Analysis (FEA) of pipelines and related components. This methodology is particularly useful in the assessment of existing systems when linear elastic numerical analysis shows that local stresses may exceed the elastic design limits. Two case studies are presented showing analyses performed with Abaqus [5], a commercial, general purpose FEA software package. The first case study provides an assessment of a large diameter elbow where the stress on the outer fibers of the intrados exceeded the longitudinal stress limits from B31.8. The second case study examines an assessment of a tee connection where the stresses on the ID exceeded the yield strength of the component. In addition to the case studies, the paper also presents the results of a full-scale test that demonstrated what margin was present when the numerical calculations were based on specified minimum properties. This paper is not intended to revise or replace any provision of B31.4 and/or B31.8 [1, 2]. Instead, it provides the means for calculating load factors that can be used with an elastic-plastic analysis approach in a manner that provides the same design margins as the ASME B31 codes. The approach described in this paper is intended for use in the detailed FEA of pipelines and their associated components.

Numerical Analysis of Soil Pressure inside the Sunken Large Diameter Cylindrical Structure Based on ABAQUS

2013 ◽  
Vol 353-356 ◽  
pp. 392-397 ◽  
Author(s):  
Jin Song Gui ◽  
Bo Zhang ◽  
Zhi Qi Gao ◽  
Yu Fu
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Large Scale ◽  
Large Diameter ◽  
Earth Pressure ◽  
Pressure Change ◽  
Soil Pressure ◽  
Cylindrical Structure ◽  
Finite Element Software ◽  
Pressure Calculation

The filling earth pressure calculation inside the Sunken Large Diameter Cylindrical Structure is very complex. This paper used large-scale finite element software ABAQUS to establish numerical model, and validated it by the experimental data, then analyze the main cause of earth pressure change inside the cylinder.

scholarly journals Soil-Structure Interaction of Flexible Temporary Trench Box: Parametric Studies Using 3D FE Modelling

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Miah Alam ◽  
Omar Chaallal ◽  
Bertrand Galy
Keyword(s):  
Finite Element ◽  
Plate Thickness ◽  
Earth Pressure ◽  
Material Model ◽  
Computer Code ◽  
Soil Pressure ◽  
Fe Modelling ◽  
Deep Trench ◽  
Constitutive Material Model ◽  
Sensitive Clay

This paper presents the results of two parametric finite-element studies that were carried out using the PLAXIS-3D finite element (FE) computer code. The following objectives and corresponding parameters were considered: (i) to evaluate the soil pressure on the steel trench box shield; the parameters studied were related to soil type and material, and the study considered till, dry sand, wet sand, and sensitive clay soil; (ii) to assess the effect of trench box material and geometry on earth pressure; the parameters studied were related to trench box material (steel versus aluminum) as well as geometry (plate thickness and strut diameter). These studies included simulation of two steel (or aluminum) trench box shields stacked upon each other to cover the total 6 m (20 ft) deep trench. A Mohr-Coulomb (MC) constitutive material model was chosen for FE analysis (FEA). The FEA results were compared to empirical apparent earth pressure diagrams for a sensitive clay. Comparisons showed that the parameters related to the soil and the trench box have a significant influence on earth pressures.

scholarly journals Comparative analysis of stability of large diameter steel cylinder based on FEM and limit equilibrium

2020 ◽  
Vol 198 ◽  
pp. 03026
Author(s):  
Chang-yi Yu ◽  
Ming-yue Lu
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Reduction Method ◽  
Limit Equilibrium ◽  
Large Diameter ◽  
Earth Pressure ◽  
Steel Cylinder ◽  
The Earth ◽  
Analysis Of Stability ◽  
The Stability

The stability mechanism of large-diameter steel cylinder under fill load has not yet formed a complete theory. In order to calculate the stability of the steel cylinder island arm structure in a certain project, the limit equilibrium and finite element method are used in this paper. The limit equilibrium method is based on the limit equilibrium of the soil inside and outside the steel cylinder, taking into account the earth pressure and friction force on the cylinder, and using moment equilibrium to calculate its stability coefficient. Secondly, the finite element strength reduction method is adopted to analyze the stability of the steel cylinder island arm structure by using strength parameters to correlate with the temperature field and changing the boundary conditions of the temperature field. The results and analysis methods of this paper provide references for the construction and design of the same type of projects.

Optimal Design of the Large-Diameter Spinning Torispherical Head

2012 ◽  
Vol 544 ◽  
pp. 194-199
Author(s):  
Di Zhang ◽  
Shui Ping Sheng ◽  
Zeng Liang Gao
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Large Diameter ◽  
General Purpose ◽  
Design Tool ◽  
Crown Area ◽  
Finite Element Software ◽  
The Stability

Two important parameters of torispherical head that are (interior radius of spherical crown area) and r (interior radius of transition corner) have been optimized by the module of the large general-purpose finite-element software ANSYS, targeting the strength and stability of the head. This paper provides an optimized torispherical head, which improves the stability of the edge of the head with acceptable strength of the head. The procedure is generally applicable as a design tool for optimal design.

Design of crack arrestors for ultra high grade gas transmission pipelines: simulation of crack initiation, propagation and arrest

2011 ◽  
Vol 2 (2) ◽  
pp. 307-319
Author(s):  
F. Van den Abeele ◽  
M. Di Biagio ◽  
L. Amlung
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Large Scale ◽  
Large Diameter ◽  
Pipe Material ◽  
High Grade ◽  
Gas Pipelines ◽  
Ductile Crack ◽  
Reinforced Plastics ◽  
Four Point Bending

One of the major challenges in the design of ultra high grade (X100) gas pipelines is the identification of areliable crack propagation strategy. Recent research results have shown that the newly developed highstrength and large diameter gas pipelines, when operated at severe conditions, may not be able to arrest arunning ductile crack through pipe material properties. Hence, the use of crack arrestors is required in thedesign of safe and reliable pipeline systems.A conventional crack arrestor can be a high toughness pipe insert, or a local joint with higher wall thickness.According to experimental results of full-scale burst tests, composite crack arrestors are one of the mostpromising technologies. Such crack arrestors are made of fibre reinforced plastics which provide the pipewith an additional hoop constraint. In this paper, numerical tools to simulate crack initiation, propagationand arrest in composite crack arrestors are introduced.First, the in-use behaviour of composite crack arrestors is evaluated by means of large scale tensile testsand four point bending experiments. The ability of different stress based orthotropic failure measures topredict the onset of material degradation is compared. Then, computational fracture mechanics is applied tosimulate ductile crack propagation in high pressure gas pipelines, and the corresponding crack growth inthe composite arrestor. The combination of numerical simulation and experimental research allows derivingdesign guidelines for composite crack arrestors.

scholarly journals Viscoelastic analysis of Calving Glaciers

1980 ◽  
Vol 1 ◽  
pp. 37-41 ◽  
Author(s):  
D. V. Reddy ◽  
W. Bobby ◽  
M. Arockiasamy ◽  
R. T. Dempster
Keyword(s):  
Finite Element ◽  
Sea Water ◽  
Water Pressure ◽  
Computer Code ◽  
Ice Shelf ◽  
Element Analysis ◽  
Ice Shelves ◽  
Shear Moduli ◽  
Relaxation Functions ◽  
Spring Force

Calving of floating ice shelves is studied by a viscoelastic finite-element analysis. The fan-shaped breaking-up of glaciers due to forces that cause bending on creeping ice is assumed to be axisymmetric. Bending may be due to geometry of the bcdrock, action of tides and waves, and imbalance (at the ice front) between the stress in the ice and the sea-water pressure.The bulk and shear moduli of the ice are represented by relaxation functions of the Prony series, which is a discrete relaxation spectrum composed of a constant and a summation of exponential terms. These properties are also functions of temperature, that varies over the thickness of the ice shelf. The temperature distribution across the thickness of the ice is obtained from calculations based on a linear dependence of thermal conductivity on the temperature. Numerical results are presented for various calving mechanisms. A computer code, VISIC1, is developed by modifying a finite-element viscoelastic code, VISICE, for floating ice islands. The buoyancy of the water is taken into account by a Winkler spring model, with the spring force determined from displaced volume. Locations of crack initiation obtained from the analysis are used to predict the iceberg size immediately after calving.

scholarly journals Modeling Free Surface Flows Using Stabilized Finite Element Method

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Deepak Garg ◽  
Antonella Longo ◽  
Paolo Papale
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Free Surface ◽  
Numerical Scheme ◽  
Stokes Equations ◽  
Fluid Velocity ◽  
Computer Code ◽  
Free Surface Flows ◽  
Surface Flows ◽  
Element Method

This work aims to develop a numerical wave tank for viscous and inviscid flows. The Navier-Stokes equations are solved by time-discontinuous stabilized space-time finite element method. The numerical scheme tracks the free surface location using fluid velocity. A segregated algorithm is proposed to iteratively couple the fluid flow and mesh deformation problems. The numerical scheme and the developed computer code are validated over three free surface problems: solitary wave propagation, the collision between two counter moving waves, and wave damping in a viscous fluid. The benchmark tests demonstrate that the numerical approach is effective and an attractive tool for simulating viscous and inviscid free surface flows.

Critical Flaw Size Evaluation in Butt-Fusion Joints of HDPE Pipes

2014 ◽  
Author(s):  
S. Kalyanam ◽  
P. Krishnaswamy ◽  
E. M. Focht ◽  
D.-J. Shim ◽  
F. W. Brust ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Nuclear Industry ◽  
Flaw Size ◽  
Fusion Process ◽  
Pipe Material ◽  
Element Analysis ◽  
Hdpe Pipe ◽  
Asme Code ◽  
Critical Flaw ◽  
Pipe Joints

The integrity of high density polyethylene (HDPE) piping and fusion joints are a topic of interest to the nuclear industry, regulators, ASME code, and the plastics pipe industry. The ASME Code Case N-755-1 has been approved and addresses the use of HDPE in safety related applications. Over the last few years some of the concerns identified with the parent HDPE pipe material and the fusion joints have been addressed while others are still being resolved. One such unresolved concern is the effect of the fusion process on the integrity of the joint, specifically, the introduction of flaws during the fusion process. The potential impact of flaws in the fusion joint on the service life of the HDPE piping is being evaluated. The current study calculates stress intensity factors (SIF) for circumferential flaws and uses them to evaluate the potential structural integrity of HDPE fusion joints in pipes. The recent API 579-1/ASME FFS-1 standard provides SIF (KI) solutions to various semi-elliptical and full-circumferential (360°) surface cracks/flaws on the outer surface (OD) and the inner surface (ID). The API 579-1/ASME FFS-1 standard SIF tables and finite element analysis (FEA) of selected cases were used to develop simplified SIF relations for full-circumferential surface flaws that can be used for plastic pipes with diameters ranging from 101.6 mm (4 inch) through 914.4 mm (36 inch) and dimensional ratios (DRs) from 7 through 13. Further, the SIF of embedded flaws akin to lack-of-fusion regions was evaluated. The results from this study serve as precursors to understanding and advancing experimental methods to address important issues related to the critical tolerable flaw size in the butt-fusion joint material and were utilized to select the specimen tests and hydrostatic pipe tests used to evaluate various joining processes. Further, they will help with understanding the essential variables that control the long-term component integrity and structural performance of HDPE pipe joints in ASME Class 3 nuclear piping.

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