Computer Based Process Piping Stress Analysis: ASME B31.3 Appendix S — Example S2

2006 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Operating Temperature ◽  
Stress Range ◽  
Explicit Equation ◽  
The Past ◽  
Process Piping ◽  
Piping Systems ◽  
Sustained Loads ◽  
Computer Based ◽  
Temperature And Pressure

The American Standards Association (ASA) B31.3-1959 Petroleum Refinery Piping Code [1] grew out of an ASA document that addressed all manner of fluid conveying piping systems. ASA B31.3 was created long before widespread engineering use of computer “mainframes” or even before the inception of piping stress analysis software. Also as B31.3 continued to pass thru standards organizations from ASA, ANSI, to ASME, the B31.3 Process Piping Code [2] (hereafter referred to as the “Code”) has remained ambiguous over the past few decades in several areas. The displacement stress range, SE, has always been explicitly defined by both verbiage and equation. Yet, the sustained condition(s) stress, SL, is mentioned not with an explicit equation but with a statement that the sustained stress shall be limited by the allowable stress at the corresponding operating temperature, Sh. Also one might infer from the vague verbiage in the Code that there is only one sustained condition; this would also be an incorrect inference. Also, assumptions would then have to be made as to which supports are allowed to be included in a sustained analysis based on whether the piping “lifts-off” any of the pipe supports during the corresponding operating condition. This paper describes the subtle yet possibly radical concepts that are included in the (recently approved for inclusion into) ASME B31.3-2006 Appendix S Example S2. This paper discusses: • when and in what manner the most severe set of operating temperature and pressure is to be used; • the concept of “sustained condition” and multiple “anticipated” sustained conditions; • determining the support scenario(s) for each anticipated sustained condition; • establishing the most severe sustained condition to evaluate and determine the stress due to sustained loads, SL; • utilizing an equation with sustained stress indices to evaluate SL; • establishing the least severe sustained condition and its effect in determining the largest displacement stress range, SE.

Computer Based Process Piping Stress Analysis: ASME B31.3 Appendix S — Example S1

2006 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Petroleum Refinery ◽  
Operating Temperature ◽  
The Past ◽  
Analysis Process ◽  
Process Piping ◽  
Piping Systems ◽  
Computer Based ◽  
Temperature And Pressure ◽  
Design Pressure

The American Standards Association (ASA) B31.3-1959 Petroleum Refinery Piping Code [1] grew out of an ASA document that addressed all manner of fluid conveying piping systems. ASA B31.3 was created long before widespread engineering use of computer “mainframes” or even before the inception of piping stress analysis software. Also as B31.3 continued to pass thru standards organizations from ASA, ANSI, to ASME, the B31.3 Process Piping Code [2] (hereafter referred to as the “Code”) has remained ambiguous over the past few decades in several areas. Ambiguities such as what temperatures and pressures are to be used during the pipe stress analysis process is addressed but apparently not clearly enough to make the point; the prevailing practice in the industry is to use the design pressure and temperature; but this is an incorrect inference from the Code. The misunderstandings as to the few, albeit very important, purposed uses for the design pressure and design temperature also appear to be prevalent in the industry. This paper describes some of these subtle yet possibly radical concepts that were included in the ASME B31.3-2004 Appendix S Example Sl. This paper discusses: • the design and analysis procedures in defining when the design conditions are actually to be used; • when and in what manner the most severe set of operating temperature and pressure is to be used; • and the debates that lasted over a decade to finally include into the Code such “seemingly simple” examples that address computer based stress analysis.

2010 Edition of B31.3 Process Piping Code: A First Equation for Stress Due to Sustained Loads

2010 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Operating Temperature ◽  
Allowable Stress ◽  
Stress Range ◽  
Explicit Equation ◽  
Process Piping ◽  
Sustained Loads ◽  
History Of ◽  
First Time

For the first time in the history of the ASA [1], ANSI/ASME, ASME/ANSI, to the 2008 edition of ASME B31.3 Process Piping Code (hereafter referred to as “the Code”) [2], an equation for the Stress Due To Sustained Loads, SL, has been introduced into the Code. From its inception to the current edition, the Code has remained ambiguous in several areas. Even though the displacement stress range, SE, has been explicitly defined by both text and equation, the stress due to sustained loads, SL, is mentioned not with an explicit equation but with a statement that SL shall be limited by the allowable stress at the corresponding operating temperature, Sh. This paper describes the equation in detail and the background, the events, and the effort involved that led to the insertion of this equation into the Code.

ASME B31.3 Appendices P and S: Compensating for Shortcomings

2008 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Stress Range ◽  
Analysis Software ◽  
Process Piping ◽  
Computer Based

The 2004 edition of ASME B31.3 Process Piping Code [1] introduced both Appendix P and Appendix S Example 1; Examples 2 and 3 were included in the 2006 edition. Appendix P is to illustrate a nearly computer stress analysis basis by defining alternative rules for displacement stress range evaluation, and Appendix S contains examples describing how to satisfy the requirements of B31.3 when performing computer based stress analysis. As is possible with any extensive addition to any code, these first offerings contained shortcomings either explicitly or by lack of clarity. This paper discusses some of these issues, provides workarounds when using today’s commercially available piping stress analysis software, and proposes revisions to both Appendices for the 2010 edition of the B31.3 Process Piping Code.

Computer Piping Analysis, ASME B31.3 Appendix S: Example S3 — Moment Reversal

2007 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Stress Analysis ◽  
Petroleum Refinery ◽  
Axial Stress ◽  
Piping System ◽  
Stress Range ◽  
Analysis Software ◽  
Process Piping ◽  
Piping Systems ◽  
Operating Stress ◽  
The Impact

The American Standards Association (ASA) B31.3-1959 Petroleum Refinery Piping Code [1] grew out of an ASA document that addressed all manner of fluid conveying piping systems. ASA B31.3 was created long before widespread engineering use of computer “mainframes” or even before the inception of piping stress analysis software. From its inception until recent times, the B31.3 Process Piping Code [2] (hereafter referred to as the “Code”) has remained ambiguous in several areas. This paper describes some of these subtle concepts that are included in the Code 2006 Edition for Appendix S Example S3. This paper discusses: • the effect of moment reversal in determining the largest Displacement Stress Range, • the impact of the average axial stress caused by displacement strains on the Example S3 piping system and the augmenting of the Code Eq. (17) thereto, • a brief comparison of Example S3 results to that of the operating stress range evaluated in accordance with the 2006 Code Appendix P Alternative Requirements.

Critical Analysis of the New High Cycle Fatigue Assessment Procedure From ASME B31.3—Appendix W

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Nikola Jaćimović ◽  
Sondre Luca Helgesen
Keyword(s):  
High Cycle Fatigue ◽  
Design Procedure ◽  
Piping System ◽  
Assessment Procedure ◽  
Stress Range ◽  
Cycle Fatigue ◽  
Fatigue Design ◽  
Process Piping ◽  
Piping Systems ◽  
Fatigue Evaluation

Abstract ASME B31.3, the leading process piping system design code, has included in its 2018 edition a new procedure for evaluation of high cycle fatigue in process piping systems. As stated in the Appendix W of ASME B31.3-2018, this new procedure is applicable to any load resulting in the stress range in excess of 20.7 MPa (3.0 ksi) and with the total number of cycles exceeding 100,000. However, this new procedure is based on the stress range calculation typical to ASME B31 codes which underestimates the realistic expansion stress range by a factor of ∼2. While the allowable stress range used typically for fatigue evaluation of piping systems is adjusted to take into consideration this fact, the new fatigue design curves seem not to take it into account. Moreover, the applicability of the new design procedure (i.e., welded joint fatigue design curves) to the components which tend to fail away from the bends is questionable. Two examples are presented at the end of the paper in order to substantiate the indicated inconsistencies in the verification philosophy.

Analysis of Piping Systems for Life Extension of Heavy Water Plants in India

2002 ◽  
Author(s):  
Rajesh K. Mishra ◽  
R. S. Soni ◽  
H. S. Kushwaha ◽  
V. Venkat Raj
Keyword(s):  
Thermal Expansion ◽  
Heavy Water ◽  
Past History ◽  
Plant Performance ◽  
Life Extension ◽  
The Past ◽  
Piping Systems ◽  
Sustained Loads ◽  
High Fatigue ◽  
Water Plants

Heavy water production in India has achieved many milestones in the past. Two of the successfully running heavy water plants are on the verge of completion of their design life in the near future. One of these two plants, situated at Kota, is a hydrogen sulfide based plant and the other one at Tuticorin is an ammonia-based plant. Various exercises have been planned with an aim to assess the fatigue usage for the various components of these plants in order to extend their life. Considering the process parameters and the past history of the plant performance, critical piping systems and equipment are identified. Analyses have been carried out for these critical piping systems for mainly two kinds of loading, viz. sustained loads and the expansion loads. Static analysis has been carried out to find the induced stress levels due to sustained as well as thermal expansion loading as per the design code ANSI B31.3. Due consideration has been given to the design corrosion allowance while evaluating the stresses due to sustained loads. At the locations where the induced stresses (SL) due to the sustained loads are exceeding the allowable limits (Sh), exercises have been carried out considering the reduced corrosion allowance value. This strategy is adopted in view of the fact that the thickness measurements carried out at site at various critical locations show a very low rate of corrosion. It has been possible to qualify the system with reduced corrosion allowance values however, it is recommended to keep that location under periodic monitoring. The strategy adopted for carrying out analysis for thermal expansion loading is to qualify the system as per the code allowable value (Sa). If the stresses are more than the allowable value, credit of liberal allowable value as suggested in the code i.e., with the addition of the term (Sh-SL) to the term 0.25 Sh, has been taken. However, if at any location, it is found that thermal stress is high, fatigue analysis has been carried out. This is done using the provisions of ASME Code Section VIII, Div. 2 by evaluating the cumulative fatigue usage factor. Results of these exercises reveal that the piping systems of both of these plants are in a very healthy state. Based on these exercises, it has been concluded that the life of the plants can be safely extended further with enhanced in-service inspection provisions.

2010 Edition of B31.3 Process Piping Code: New Allowables for Appendix P—Alternative Stress Range Rules

2011 ◽  
Author(s):  
Don R. Edwards
Keyword(s):  
Fatigue Failure ◽  
Stress Range ◽  
Singular Stress ◽  
Alternative Method ◽  
Text Base ◽  
Process Piping ◽  
Piping Systems ◽  
Operating Stress ◽  
Base Text

Appendix P Alternative Rules for Stress Range Evaluation was first introduced into the 2004 edition of ASME B31.3 Process Piping Code [1] as an alternative method that was conceived to be more computer friendly and possibly a more nearly theoretically defensible method of protecting piping systems individually against fatigue failure and dimensional ratchet than the singular stress range requirements of the Code’s base text (“base Code”). This paper describes the progression of events that led up to the inception of the Appendix and the subsequent revisions to same and detailing the reason for the 2010’s newly coined Allowable Operating Stress to protect against dimensional ratchet and Allowable Operating Stress Range to protect against fatigue failure.

scholarly journals Novel AI driven approach to classify infant motor functions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon Reich ◽  
Dajie Zhang ◽  
Tomas Kulvicius ◽  
Sven Bölte ◽  
Karin Nielsen-Saines ◽  
...  
Keyword(s):  
Learning Algorithm ◽  
Movement Pattern ◽  
Video Stream ◽  
Typically Developing ◽  
The Past ◽  
Movement Assessment ◽  
Computer Based ◽  
Ablation Study ◽  
First Time ◽  
Efficient Screening

AbstractThe past decade has evinced a boom of computer-based approaches to aid movement assessment in early infancy. Increasing interests have been dedicated to develop AI driven approaches to complement the classic Prechtl general movements assessment (GMA). This study proposes a novel machine learning algorithm to detect an age-specific movement pattern, the fidgety movements (FMs), in a prospectively collected sample of typically developing infants. Participants were recorded using a passive, single camera RGB video stream. The dataset of 2800 five-second snippets was annotated by two well-trained and experienced GMA assessors, with excellent inter- and intra-rater reliabilities. Using OpenPose, the infant full pose was recovered from the video stream in the form of a 25-points skeleton. This skeleton was used as input vector for a shallow multilayer neural network (SMNN). An ablation study was performed to justify the network’s architecture and hyperparameters. We show for the first time that the SMNN is sufficient to discriminate fidgety from non-fidgety movements in a sample of age-specific typical movements with a classification accuracy of 88%. The computer-based solutions will complement original GMA to consistently perform accurate and efficient screening and diagnosis that may become universally accessible in daily clinical practice in the future.

Crankshaft Stress Analysis—Combination of Finite Element and Classical Analysis Techniques

1990 ◽  
Vol 112 (3) ◽  
pp. 268-275 ◽  
Author(s):  
A. R. Heath ◽  
P. M. McNamara
Keyword(s):  
Stress Analysis ◽  
Concept Design ◽  
Low Friction ◽  
Failure Investigation ◽  
Engine Design ◽  
Computer Based ◽  
Analysis System ◽  
High Level ◽  
Engine Components ◽  
Oil Films

The conflicting legislative and customer pressures on engine design, for example, combining low friction and a high level of refinement, require sophisticated tools if competitive designs are to be realized. This is particularly true of crankshafts, probably the most analyzed of all engine components. This paper describes the hierarchy of methods used for crankshaft stress analysis with case studies. A computer-based analysis system is described that combines FE and classical methods to allow optimized designs to be produced efficiently. At the lowest level simplified classical techniques are integrated into the CAD-based design process. These methods give the rapid feedback necessary to perform concept design iterations. Various levels of FE analysis are available to carry out more detailed analyses of the crankshaft. The FE studies may feed information to or take information from the classical methods. At the highest level a method for including the load sharing effects of the flexible crankshaft within a flexible block interconnected by nonlinear oil films is described. This method includes the FE modeling of the complete crankshaft and the consideration of its stress field throughout an engine cycle. Fatigue assessment is performed to calculate the distribution of fatigue safety factor on the surface of the crankshaft. This level of analysis can be used for failure investigation, or detailed design optimization and verification. The method is compatible with those used for vibration and oil film analysis.

The evolution of computer-based analysis of high-resolution CT of the chest in patients with IPF

2021 ◽  
pp. 20200944
Author(s):  
Lucio Calandriello ◽  
Simon LF Walsh
Keyword(s):  
High Resolution ◽  
Computer Technology ◽  
Response To Treatment ◽  
Visual Interpretation ◽  
Future Directions ◽  
The Past ◽  
High Resolution Ct ◽  
Ct Analysis ◽  
Computer Based ◽  
Fibrotic Lung Disease

In patients with idiopathic pulmonary fibrosis (IPF), there is an urgent need of biomarkers which can predict disease behaviour or response to treatment. Most published studies report results based on continuous data which can be difficult to apply to individual patients in clinical practice. Having antifibrotic therapies makes it even more important that we can accurately diagnose and prognosticate in IPF patients. Advances in computer technology over the past decade have provided computer-based methods for objectively quantifying fibrotic lung disease on high-resolution CT of the chest with greater strength than visual CT analysis scores. These computer-based methods and, more recently, the arrival of deep learning-based image analysis might provide a response to these unsolved problems. The purpose of this commentary is to provide insights into the problems associated with visual interpretation of HRCT, describe of the current technologies used to provide quantification of disease on HRCT and prognostication in IPF patients, discuss challenges to the implementation of this technology and future directions.

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