Assessment of Dents Under High Longitudinal Strain

2018 ◽  
Author(s):  
Bo Wang ◽  
Yong-Yi Wang ◽  
Brent Ayton ◽  
Mark Stephens ◽  
Steve Nanney
Keyword(s):  
Longitudinal Strain ◽  
Scale Validation ◽  
Compressive Strain ◽  
Full Scale ◽  
Ground Movement ◽  
Strain Capacity ◽  
Parametric Analyses ◽  
Full Scale Tests ◽  
Assessment Procedures ◽  
The Impact

Pipeline construction activities and in-service interference events can frequently result in dents on the pipe. The pipelines can also experience high longitudinal strain in areas of ground movement and seismic activity. Current assessment procedures for dents were developed and validated under the assumption that the predominant loading is internal pressure and that the level of longitudinal strain is low. The behavior of dents under high longitudinal strain is not known. This paper discusses work funded by US DOT PHMSA on the assessment of dents under high longitudinal strain. Parametric numerical analyses were conducted to identify and examine key parameters and mechanisms controlling the compressive strain capacity (CSC) of pipes with dents. Selected full-scale tests were also conducted to experimentally examine the impact of dents on CSC. The focus of this work was on CSC because tensile strain capacity is known not to be significantly affected by the presence of dents. Through the parametric analyses and full-scale validation tests, guidelines on the CSC assessment of dented pipes under high longitudinal strain were developed.

Burst Pressure of Wrinkles Under High Longitudinal Strain

2018 ◽  
Author(s):  
Honggang Zhou ◽  
Yong-Yi Wang ◽  
Steve Nanney
Keyword(s):  
Longitudinal Strain ◽  
Biaxial Loading ◽  
Full Scale ◽  
Ground Movement ◽  
Burst Pressure ◽  
Current Assessment ◽  
Full Scale Tests ◽  
Assessment Procedures ◽  
The Impact ◽  
Longitudinal Strains

Wrinkles may form in pipelines experiencing high longitudinal strains in areas of ground movement and seismic activities. Current assessment procedures for wrinkles were developed and validated under the assumption that the predominant loading was internal pressure and that the level of longitudinal strain was low. The impact of wrinkles on the burst pressure of pipes under high longitudinal strain is not known. This paper describes work funded by US DOT PHMSA on the assessment of burst pressure of wrinkled pipes under high longitudinal strain. Both numerical analyses and full-scale tests were conducted to examine the burst pressure of wrinkled pipes. The numerical analysis results were compared with the full-scale test data. The effect of wrinkles on burst pressure were discussed. The biaxial loading conditions in the pipe were found affect the burst pressure of wrinkled pipes.

Tensile and Compressive Strain Capacity in the Presence of Corrosion Anomalies

2018 ◽  
Author(s):  
Honggang Zhou ◽  
Yong-Yi Wang ◽  
Mark Stephens ◽  
Jason Bergman ◽  
Steve Nanney
Keyword(s):  
Compressive Strain ◽  
General Corrosion ◽  
Department Of Transportation ◽  
Strain Capacity ◽  
Analytical Work ◽  
The Us ◽  
Different Types ◽  
Full Scale Tests ◽  
The Impact ◽  
Tensile Strain Capacity

Over the past 15 years, extensive studies have been conducted on the tensile strain capacity (TSC) and compressive strain capacity (CSC) of pipelines. The existing studies were mainly targeted at the design and construction of new pipelines. However, the impact of anomalies (e.g., corrosion anomalies) on the TSC and CSC has not been explicitly and adequately considered. This paper summarizes work performed as part of a major effort funded by the US Department of Transportation Pipeline and Hazardous Materials Safety Administration (DOT PHMSA) aimed at examining the impact of corrosion anomalies on the TSC and CSC of pipelines. In this work, the strain capacities were examined analytically, and the analytical work was compared to results from selected full-scale tests. Based on the summarized work, guidelines were developed for assessing the TSC and the CSC of corroded pipes. The guidelines are applicable to different types of corrosion anomalies, including circumferential grooves, longitudinal grooves and general corrosion. The strain capacities can be calculated using the key material properties and dimensions of pipe and corrosion anomalies as inputs.

Burst Pressure of Pipelines With Corrosion Anomalies Under High Longitudinal Strains

2018 ◽  
Author(s):  
Honggang Zhou ◽  
Yong-Yi Wang ◽  
Mark Stephens ◽  
Jason Bergman ◽  
Steve Nanney
Keyword(s):  
Numerical Analysis ◽  
Longitudinal Strain ◽  
Compressive Strain ◽  
Experimental Tests ◽  
Burst Pressure ◽  
General Corrosion ◽  
The Us ◽  
Full Scale Tests ◽  
The Impact ◽  
Longitudinal Strains

Existing corrosion assessment models were developed and validated under the assumption that internal pressure was the principal driver for burst failure and that longitudinal strain levels were low. The impact of moderate to high levels of longitudinal strain on burst capacity had not been explicitly considered. This paper summarizes work performed as part of a major effort funded by the US Department of Transportation Pipeline and Hazardous Materials Safety Administration (DOT PHMSA) aimed at examining the impact of longitudinal strain on the integrity of pipelines with corrosion anomalies. This paper focuses on the burst pressure of corroded pipes under high longitudinal strains. It is known that longitudinal tensile strain does not reduce the burst pressure relative to that of pipes subjected to low longitudinal strains. Therefore, existing burst pressure models can be considered adequate when the longitudinal strain is tensile. However, longitudinal compressive strain was found to lead to a moderate reduction in burst pressure. Numerical analyses were conducted to study the effect of longitudinal compressive strain on the burst pressure of corroded pipes. A burst pressure reduction formula was developed as a function of the longitudinal compressive strain. Full-scale tests were conducted to confirm the findings of the numerical analysis. Guidelines for assessing the burst pressure of corroded pipes under high longitudinal compressive strains were developed from the outcome of numerical analysis and experimental tests. The guidelines are applicable to different types of corrosion anomalies, including circumferential grooves, longitudinal grooves and general corrosion.

TurkStream Collapse Test Program

2018 ◽  
Author(s):  
Chris Timms ◽  
Doug Swanek ◽  
Duane DeGeer ◽  
Arjen Meijer ◽  
Ping Liu ◽  
...  
Keyword(s):  
Thermal Ageing ◽  
Full Scale ◽  
The Black Sea ◽  
Small Scale ◽  
Test Program ◽  
Line Pipe ◽  
Medium Scale ◽  
Collapse Resistance ◽  
Full Scale Tests ◽  
The Impact

The TurkStream pipeline project is designed to transport approximately 32 billion cubic meters of natural gas annually from Russia to Turkey under the Black Sea, with more than 85% of the deep-water route being deeper than 2000 m. The offshore section is intended to consist of two parallel lines, each approximately 900 km long. The preliminary stages of the front end engineering design (pre-FEED) phase was managed by INTECSEA. To support the analyses and design of the deepest portions, a full scale collapse test program was performed by C-FER Technologies (C-FER). This collapse test program, which included 62 full-scale collapse and pressure+bend tests, 54 medium-scale ring collapse tests, and hundreds of small-scale tests, was primarily aimed at measuring, quantifying and documenting the increase in pipe strength and collapse resistance resulting from the thermal induction heat treatment effect (thermal ageing) that arises during the pipe coating process. Two grades of 32-inch (813 mm) outside diameter (OD) line-pipe, SAWL450 and SAWL485 with wall thicknesses of 39.0 mm or 37.4 mm, respectively, were supplied from various mills for testing. The collapse test program objectives were as follows: • Determine the collapse resistance of line pipes originating from various pipe mills; • Determine the pressure+bend performance of line pipes originating from various pipe mills; • Measure the effect of thermal ageing on material and collapse testing results, including the impact of multiple thermal cycles; and • Evaluate the results of medium-scale ring collapse tests as compared to full-scale tests. This paper presents selected results of this work, along with some comparisons to predictive equations.

scholarly journals LABORATORY OBSERVATIONS OF IMPACTS ON COARSE SEDIMENT BEACHES

2011 ◽  
Vol 1 (32) ◽  
pp. 53
Author(s):  
Ian Ball ◽  
Edgar Mendoza-Baldwin ◽  
David Simmonds ◽  
Adrián Pedrozo-Acuña ◽  
Dominic E Reeve
Keyword(s):  
Full Scale ◽  
Impact Pressure ◽  
Coarse Grained ◽  
Laboratory Measurements ◽  
Coarse Sediment ◽  
Full Scale Tests ◽  
The Impact ◽  
Impact Events ◽  
Plunging Breaker

In this paper we present laboratory observations of plunging wave breaker impact pressure responses on a steep coarse-grained beach, extending previous work conducted by Pedrozo-Acuña et al. (2008). Scale laboratory measurements of plunging breaker impact events are reported and compared with the previous full-scale tests. These tests extend the previous relationships to a wider range of surf-similarity parameters and indicate a continued reduction in impact pressure as the transition from plunging impacts to surging impacts is approached. Additional results from scale tests conducted on a smooth impermeable slope also indicate the presence of a maximum impact pressure within the plunging breaker region; however also suggest it may be necessary to include roughness and permeability in the parameterization of the impact pressure.

Alternative Compressive Strain Capacity Performance Limits for Strain Based Design Applications

2016 ◽  
Author(s):  
Shawn Kenny ◽  
Robin Gordon ◽  
Greg Swank
Keyword(s):  
Structural Engineering ◽  
Negative Impact ◽  
Numerical Study ◽  
Compressive Strain ◽  
Elastic Stability ◽  
Ground Movement ◽  
Performance Limits ◽  
Strain Capacity ◽  
Industry Standards ◽  
Limiting Condition

Existing industry standards have established the compressive strain capacity of pipelines within an empirical basis. The compressive strain capacity is generally associated with the peak moment. This approach has evolved from elastic stability concepts used in structural engineering for unrestrained pipe segments subject to primary loading (i.e. force or load control) conditions. This limiting condition does not take advantage of the observed performance for buried pipelines, when subjected to displacement control events such as differential ground movement, where the pipe curvature can exceed the peak moment response without loss of pressure containment integrity. This inherent conservatism may have a negative impact on project economics or sanction where the compressive strain capacity, rather than tensile rupture limits, governs the strain based design methodology. For these conditions, alternative performance limits defining the pipe compressive strain capacity are required. A numerical study was conducted, using finite element methods, to examine possible alternative compressive strain criteria for use in strain-based design applications. The results from this study and the requirements to bring these concepts forward through integration with industry recommended practice are presented.

scholarly journals Effect of Maneuvering on Ice-Induced Loading on Ship Hull: Dedicated Full-Scale Tests in the Baltic Sea

2020 ◽  
Vol 8 (10) ◽  
pp. 759
Author(s):  
Mikko Suominen ◽  
Fang Li ◽  
Liangliang Lu ◽  
Pentti Kujala ◽  
Anriëtte Bekker ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Measurement Data ◽  
Full Scale ◽  
The Baltic Sea ◽  
Load Duration ◽  
Ship Control ◽  
Level Ice ◽  
The Baltic ◽  
Full Scale Tests ◽  
The Impact

Maneuvers in level ice are common operations for icebreakers and polar supply vessels. Maneuvering exposes the midship and stern area to ice interaction, influencing the magnitude and frequency of ice-induced loading in these areas. However, full-scale measurements do not typically cover the midship and stern areas, as measurements have commonly focused on the bow area. Controlled maneuvering tests were conducted during the ice trials of S.A. Agulhas II in the Baltic Sea. During these tests, ice-induced loading at different hull areas was measured simultaneously with ship control, navigation, and ice condition data. This work studied the effect of maneuvers on the characteristics and statistics of ice-induced loading at different hull areas and compared the impact to ahead operations. The study showed that the maneuvers had minor impact to the magnitude, frequency, and duration of loading at the bow and bow shoulder. On the other hand, maneuvers had a clear effect on the load magnitude and frequency at the stern shoulder. Additionally, a statistical analysis showed that the load magnitude increased as a function of load duration in all hull areas. Furthermore, the analyzed measurement data are presented and made available with the paper.

Large Scale Tests of Strain Capacity of Pipe Sections With Circumferential Defects Subjected to Installation-Induced Plastic Strain History

2009 ◽  
Author(s):  
Ba˚rd Nyhus ◽  
Erling O̸stby ◽  
Zhiliang Zhang ◽  
Erlend Olso̸ ◽  
Per Arne Ro̸stadsand ◽  
...  
Keyword(s):  
Large Scale ◽  
Base Material ◽  
Bending Moment ◽  
Full Scale ◽  
Strain History ◽  
Strain Capacity ◽  
Four Point Bending ◽  
Full Scale Tests ◽  
Circumferential Defects ◽  
Large Scale Tests

Installation of offshore pipelines by reeling introduces plastic pre-straining. The pre-strain history is not homogenous and it will vary around the circumference of the pipe. The pre-strain history will modify the yield and flow properties. Also, the fracture toughness may be influenced by the pre-straining. The result is that the bending strain capacity of pipelines during operation will differ depending on how the bending moment coincides with pipe orientation during installation. Three full scale tests of 12″ x-60 pipes with wall thickness 19.3mm and a 3×100 mm outer surface defect were performed to investigate the effect of pre-strain history. Two pipes were pre-strained in bending to 2% strain in the outer fibre and then straightened to simulate the reeling. The final tests to establish the strain capacity during operation as a function of strain history were performed in four point bending with an internal pressure of 325 bar. The strain capacity for the side of the pipe that ends in tension and the side that ends in compression from pre-straining was 1.7% and 2.6% respectively. The strain capacity of the third test without pre-straining was 5.7%. The results show that pre-straining will modify the strain capacity and the effect must be taken into account in engineering critical assessment of pipes during operation. The effect of prestraining should be evaluated for all installation methods that involve plastic deformation during installation, and not only reeling. It is important to note that the notch size in the full scale tests was larger than what would normally be accepted for reeling. In addition the notch was positioned in base material and not in weld metal, which is a more realistic position for a notch. The welds are normally overmatched and this might reduce the effect of prestraining.

The Influence of the UOE-SAWL Forming Process on the Collapse Resistance of Deepwater Linepipe

2011 ◽  
Author(s):  
Luciano O. Mantovano ◽  
Mohamed R. Chebaro ◽  
Hugo A. Ernst ◽  
Marcos de Souza ◽  
Chris M. Timms ◽  
...  
Keyword(s):  
Thermal Ageing ◽  
Full Scale ◽  
Sensitivity Analyses ◽  
Experimental Chamber ◽  
Forming Process ◽  
Cold Forming ◽  
Collapse Resistance ◽  
Expansion Stage ◽  
Full Scale Tests ◽  
The Impact

The UOE-SAWL pipe manufacturing process introduces considerable plastic deformations and residual stresses to feedstock plate material. Previous experimental and analytical studies have demonstrated that the effects of this process, predominantly in its final expansion stage, significantly reduce the collapse resistance of deepwater linepipe. Finite element analyses, sensitivity analyses and full-scale tests were conducted by Tenaris and C-FER Technologies (C-FER) over the last several years to better comprehend the impact of cold forming on collapse resistance. This paper presents the findings of the latest segment of this ongoing study, the objective of which was to optimize the collapse resistance of UOE-SAWL linepipe by varying three key thermal ageing parameters: time, temperature and number of thermal cycles. Six X70M and four X80M UOE pipe samples were manufactured and thermally treated with varied parameters. Full-scale collapse and buckle propagation tests were then carried out in an experimental chamber that simulates deepwater conditions. These experimental results were evaluated with respect to collapse predictions from API RP 1111 and DNV OS-F101. Material and ring splitting tests were also performed on samples obtained from these pipes to better assess the extent of the UOE pipe collapse resistance recovery. The outcomes of this study will be employed to further optimize the collapse resistance of subsea linepipe in order to reduce material and offshore installation costs.

Effect of Light Poles on Vehicle Impacts with Roadside Barriers

1997 ◽  
Vol 1599 (1) ◽  
pp. 32-39 ◽  
Author(s):  
James C. Kennedy
Keyword(s):  
Full Scale ◽  
Lack Of Information ◽  
Large Numbers ◽  
Highway Network ◽  
Accident Data ◽  
Full Scale Tests ◽  
Light Pole ◽  
National Cooperative ◽  
The Impact ◽  
Crash Tests

Light poles installed within the deflection zone of roadside barriers (guardrails) may influence the ability of the guardrail to safely redirect an impacting vehicle. One concern is that, during an impact, the vehicle may pivot about the relatively rigid light pole and then spin away from the guardrail back into the traffic stream in an uncontrolled, unsafe manner. A large percentage of the highway network in Ohio uses the type of guardrail and light pole configurations, in which the breakaway light poles are placed at either 15.2- or 45.7-cm (6- or 18-in.) lateral distance from the back of the guardrail, depending on one of two light pole base designs in use. These pole-guardrail systems were placed in large numbers some years ago and Ohio accident data have been inadequate to provide information to determine whether or not a problem exists with this system. Proposed highway rehabilitation and reconstruction projects can include changes or adjustments to placement of guardrails and light poles, but there was a lack of information as to whether or not the past practices possessed a problem. A study was conducted to determine if light poles have an adverse effect on the redirecting performance of guardrails. It included six full-scale crash tests involving two vehicle weight classes (2000P and 820C), two light pole base designs (AT-A and AT-X), and a typical guardrail used in Ohio [Type 5 (W-Beam)]. All full-scale tests were carried out according to the recommended procedures in National Cooperative Highway Research Program (NCHRP) Report 350. The actual vehicles used for the 2000P class were half-ton pickup trucks ballasted to simulate the weight and mass characteristics of the 2000P vehicle that is specified in NCHRP Report 350. The guardrail–light pole system was not shown to cause snagging or subsequent unstable motion of the vehicle due to impact. All vehicles exited the guardrail in a stable manner. No change in the arrangement of light poles behind the Type 5 guardrail is contemplated. The redirecting function of the guardrail was not compromised as a result of placement of the light pole behind the length-of-need. Excessive exit angle situations (according to NCHRP Report 350) occurred in three tests involving the simulated 2000P class vehicles. However, the impact conditions employed for these tests were extreme, and the likelihood of this situation occurring under everyday highway usage may be small.

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