Improved Semi-Quantitative Reliability-Based Method for Assessment of Pipeline Dents With Stress Risers

Abstract Increasing age expectations and number of joint replacement procedures have made interprosthetic femoral fractures (IFF) a progressively more common diagnosis and a challenge for surgeons. A gold standard and universally accepted classifications and guidelines do not exist yet. Customized structured electronic searches performed in PubMed database. Relevant key terms: IFF, classification interprosthetic fracture, peri-implant femoral fracture, biomechanics interprosthetic femur fracture, radiographic femur fracture, risk factor IFF. 42 articles finally included (up to 2019). High morbidity and mortality linked to IFF. Standardised classifications, management guidelines and surgical approaches are not available yet. Periprosthetic classification systems are still utilized even if not entirely appropriate. High rate of failure is related to thinner cortical bone, larger medullary canals and variable stresses depending on the distance among implants. High complication rates in all studies. Stress risers and implant stability based on fracture patterns and stress forces. Several surgical options with no uniformity. Less invasive surgical procedures are associated to reduction of metalwork failure rate, better preservation of vascularization and better functional-clinical outcomes. Lack of specific classification systems and management guidelines. Several surgical options are available with no uniformity of results. Attention to stress risers and preservation of bone stock and vascularization are key aspects for better results.

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Modified Kalish osteotomy: A simple approach to minimizing proximal dorsal stress risers

The Journal of Foot & Ankle Surgery ◽

10.1016/s1067-2516(03)70011-8 ◽

2003 ◽

Vol 42 (2) ◽

pp. 108-110 ◽

Cited By ~ 1

Author(s):

Matthew C. Dairman ◽

Daniel J. Hatch

Keyword(s):

Simple Approach ◽

Stress Risers

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Dumbbell Test Method for Evaluation of the Early Age Cracking Property of Concrete Material by Stress Risers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.503-504.473 ◽

2012 ◽

Vol 503-504 ◽

pp. 473-476

Author(s):

Yan Liu ◽

Zhi Gang Luo ◽

Jie Cao

Keyword(s):

Test Method ◽

Early Age ◽

Construction Site ◽

Quick Method ◽

Concrete Material ◽

Stress Risers ◽

Test Technology ◽

Cracking Performance ◽

Simulated Test ◽

Job Site

This article develops one new test technology, dumbbell test method, for evaluation of the early age cracking property of Concrete Material under constraint conditions. Its exercise of stress risers could lead concrete to crack quickly, providing a quick method to evaluate the early age crack performance of concrete material and to perform simulated test at job site conveniently. By this method, the anti-cracking performance of different concrete material can be evaluated quickly in the construction site.

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Improved Semi-Quantitative Reliability-Based Method for Assessment of Pipeline Dents With Stress Risers

Volume 1: Pipeline and Facilities Integrity ◽

10.1115/ipc2020-9472 ◽

2020 ◽

Author(s):

Amandeep Singh Virk ◽

Doug Langer ◽

Janine Woo ◽

Nader Yoosef-Ghodsi ◽

Muntaseer Kainat

Keyword(s):

The United States ◽

Radius Of Curvature ◽

Pressure Cycling ◽

Stress Risers ◽

Fitting Method ◽

Quantitative Analysis Method ◽

Comprehensive Reliability ◽

Reported Data ◽

Improved Model ◽

Integrity Analysis

Abstract Dents, especially those interacting with stress risers, can pose integrity threats to pipeline systems. Regulations in Canada and the United States mandate the repair of dents based on depth and interaction with stress risers, however, there have been cases in the past where dents that have passed these criteria have ended up in loss of containment. Recent industry’s recommendations regarding dent integrity analysis are predominantly based on strain, and the dent-fatigue models have been proven to be limited in their application. Additionally, these models or methodologies are generally deterministic which may not fully account for uncertainties associated with pipe properties and in-line inspection (ILI) tool measurement. Enbridge Liquid Pipelines Inc. had previously presented a framework to support system wide dent assessment with an efficient probabilistic-based calibrated semi-quantitative analysis method for dents (SQuAD), which elicits potentially injurious features from thousands of features within a system in a reasonable analysis timeframe. This paper expands on the authors’ previous work and presents several improvements that have since been made to the SQuAD model to address the limitations in the initial version of the model. The previous version of SQuAD was strain-based and did not explicitly account for pressure-cycling induced, fatigue-based failure quantitatively. An approximate circle fitting method was adopted for estimating the dent’s radii of curvature in order to calculate strains. In the improved model, filtering techniques have been employed to reduce the noise in the ILI-reported data while preserving the dent shape. Furthermore, a simplified FEA process has been developed to calculate the stresses within a dent due to pressure cycles, thus the fatigue-based Probability of Failure (PoF) of a dent can now be estimated using S-N approach. The filtered data allows for better accuracy in quantifying the radius of curvature of dents as reported by ILI tools, which are used for calculating dent strain as recommended in the updated version of ASME B31.8, Appendix R. Finally, the feasibility of applying this improved SQuAD model is discussed from an operator’s perspective. The improvements allow the enhanced SQuAD model to be used as an effective screening tool on a system-wide basis as part of a comprehensive, reliability-based dent assessment framework.

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An experimental study of the mechanical properties of seamless and overlapped stitched composite tubes under hydrostatic pressure, lateral compression, and impact

The Journal of Strain Analysis for Engineering Design ◽

10.1177/0309324720922749 ◽

2020 ◽

Vol 55 (7-8) ◽

pp. 212-221

Author(s):

Masoud Yekani Fard ◽

Brian Raji ◽

Bao Doan ◽

Michael Brooks ◽

John Woodward ◽

...

Keyword(s):

Mechanical Properties ◽

Hydrostatic Pressure ◽

Maximum Pressure ◽

Seamless Tube ◽

Lateral Compression ◽

Composite Tubes ◽

Functional Failure ◽

Stress Risers ◽

The Matrix ◽

Extent Of Damage

Mechanical properties and damage mechanisms of closed circular preforms and overlapped stitched composite tubes under lateral compression, impact, and hydrostatic pressure were studied. The functional failure pressures of the tubes with different boundary conditions were determined and compared. Stitch at the overlapped zone creates stress risers that lead to premature functional failure at a hydrostatic pressure at ∼1/3 of the theoretical maximum pressure of the tube as delamination occurs at the overlapping region. Seamless tubes reached values close to theoretical operating hydrostatic pressures before leakage was observed at the tube ends. The deflection of the overlapped stitched tube due to lateral compression is less than the deflection in the seamless tube, and it is limited to 5% of the inner diameter using the Spangler equation. Brittle kinks, cracks, and delamination occur in overlapped stitched tubes while seamless tubes regain the shape with limited localized cracks after unloading. The fabric architecture of a seamless tube allows for the reorientation of fiber tows as cracks develop in the matrix, thus resulting in a lesser extent of damage when the tube is subject to impact.

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Semi-Quantitative Reliability-Based Ranking Method for Assessment of Pipeline Dents With Stress Risers

Volume 2: Pipeline Safety Management Systems; Project Management, Design, Construction, and Environmental Issues; Strain Based Design; Risk and Reliability; Northern Offshore and Production Pipelines ◽

10.1115/ipc2018-78156 ◽

2018 ◽

Author(s):

Doug Langer ◽

Sherif Hassanien ◽

Janine Woo

Keyword(s):

Complex Geometry ◽

Limit State ◽

Operating Conditions ◽

Pipeline System ◽

Element Analysis ◽

Modeling And Analysis ◽

Base Level ◽

Stress Risers ◽

Short Period ◽

Detailed Assessment

Current regulations for prediction and management of potential delayed failures from existing pipeline dents rely primarily on depth and conservative assumptions related to threat interactions, which have shown limited correlation with industry failures. Such miscorrelation can lead to challenges in managing effectiveness and efficiency of pipeline integrity programs. Leading integrity techniques that entail detailed assessment of complex dent features rely on the use of finite element analysis, which tends to be inefficient for managing large pipeline systems due to prohibitively complex modeling and analysis procedures. While efforts are underway to improve dent assessment models across the industry, these often require significant detailed information that might not be available to operators; moreover, they suffer scattered model error which makes them susceptible to unclear levels of conservatism (or non-conservatism). Nevertheless, most techniques/models are deterministic in nature and neglect the effect of both aleatory and epistemic uncertainties. Operators typically utilize conservative assumptions based on subject matter experts’ opinions when planning mitigation programs in order to account for different types of uncertainties associated with the problem. This leads to inefficient dig programs (associated with significant costs) while potentially leaving dents on the pipeline which cannot be quantitatively risk assessed using current approaches. To address these concerns, the problem calls for a dent assessment framework that balances accuracy with the ability to assess dent and threat integration features at a system-wide level with available information in a practical timeframe that aligns with other integrity programs. This paper expands upon the authors’ previously published work regarding a fully quantitative reliability-based methodology for the assessment of dents interacting with stress risers. The proposed semi-quantitative reliability model leverages a strain-based limit state for plain dents (including uncertainty) with semi-quantitative factors used to account for complex geometry, stress riser interactions, and operating conditions. These factors are calibrated to reliability results from more detailed analysis and/or field findings in order to provide a simple, conservative, analytical-based ranking tool which can be used to identify features that may require more detailed assessment prior to mitigation. Initial validation results are provided alongside areas for continued development. The proposed model provides sufficient flexibility to allow it to be tailored/calibrated to reflect specific operator’s experience. The model allows for a consistent analysis of all types of dent features in a pipeline system in a short period of time to support prioritization of features while providing a base-level likelihood assessment to support calculation of risk. This novel development supports a dent management framework which includes multiple levels of analysis, using both deterministic and probabilistic techniques, to manage the threat of dents associated with stress risers across a pipeline system.

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Stress Risers Between Two Ipsilateral Intramedullary Stems

The Journal of Arthroplasty ◽

10.1016/j.arth.2004.05.002 ◽

2005 ◽

Vol 20 (3) ◽

pp. 386-391 ◽

Cited By ~ 54

Author(s):

Kazuho Iesaka ◽

Frederick J. Kummer ◽

Paul E. Di Cesare

Keyword(s):

Stress Risers

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Development of a Profile Matching Criteria to Model Dents in Pipelines Using Finite Element Analysis

Volume 5: High-Pressure Technology; ASME Nondestructive Evaluation, Diagnosis and Prognosis Division (NDPD); SPC Track for Senate ◽

10.1115/pvp2017-65278 ◽

2017 ◽

Author(s):

Janine Woo ◽

Muntaseer Kainat ◽

Samer Adeeb

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Additional Stress ◽

Element Analysis ◽

Fea Model ◽

Profile Matching ◽

Industry Standards ◽

Stress Risers ◽

Matching Criteria ◽

Key Indicators

Current industry standards cite depth and interaction with additional stress risers as the key indicators of pipeline integrity concerns in regards to dents. There have been significant efforts towards the improvement of these benchmarks in recent years. Several dent assessment methods are presented in literature, including research focused on the use of finite element analysis (FEA). The accurate assessment of dents using FEA is heavily reliant on how close the shape produced by the FEA model aligns with the shape of the actual dent. The research presented in this paper has been conducted to evaluate the sensitivity of the stresses and strains to the dent profile shape. Information regarding the existence, shape, and size of dents is typically provided by in-line inspection (ILI) tools. An FEA model is then built in commercially available software, ABAQUS, to create a dent profile that closely resembles the profile given by the ILI. The study in this paper assesses the effect of different indenter sizes on the stresses and strains within the dent and provides a recommendation to quantify the error between the ILI and FEA profiles. The process of matching a dent profile using FEA is compared to an existing analytical method to calculate strain, the equations proposed in ASME B31.8. The FEA results were found to be more conservative than the strains calculated using ASME B31.8.

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Talar Neck Fracture after United Tibiotalar Fusion

Case Reports in Orthopedics ◽

10.1155/2015/927259 ◽

2015 ◽

Vol 2015 ◽

pp. 1-4

Author(s):

W. Platt ◽

M. Welck ◽

B. Rudge

Keyword(s):

Clinical Case ◽

Early Postoperative Period ◽

High Demand ◽

Stress Risers ◽

Neck Fracture ◽

Tibiotalar Arthrodesis ◽

Original Case ◽

Ankle Trauma ◽

Foot Trauma ◽

Established Treatment

Tibiotalar arthrodesis is a well-established treatment for tibiotalar arthritis, for example, in younger high demand patients. Talar neck fractures are less common though well-recognised sequelae of foot ankle trauma. Here we present the clinical case of a 69-year-old male who presented to our institution with a nonunion of a talar neck fracture, having undergone a left tibiotalar fusion 24 years previously. To the authors’ knowledge, this injury has only been described once previously in the literature. However, the original case described a fracture sustained in the very early postoperative period following tibiotalar fusion, postulated to be secondary to postimmobilisation osteopaenia or stress risers from metalwork. The aetiology in this case is likely due to axial compression transmitted to the talar neck via the calcaneus. The predisposing factors for nonunion are discussed, highlighting the importance of vigilance for this injury in any patient with concomitant tibiotalar fusion and foot trauma. The management of this patient is discussed.

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