Application of Reliability-Based Design Method of Pipeline Material Selection

2014 ◽  
Author(s):  
Zhenyong Zhang ◽  
Wen Wei Zhang ◽  
Jinyuan Zhang ◽  
Yuqing Liu
Keyword(s):  
Failure Probability ◽  
Material Selection ◽  
Design Method ◽  
Limit State ◽  
Third Party ◽  
Ultimate Limit State ◽  
Permafrost Region ◽  
Pipe Material ◽  
Pipe Failure ◽  
Reliability Design

A certain inland pipeline is located in a cold area and traverses the alpine-cold and permafrost region. For design and selection of steel grade pipeline in such an area, the resistance of X52 and X60 pipes is calculated and analyzed using the reliability design method for the first time based on a comparison of conventional economy and technical schemes, combined with the analysis on pipe failure, reason, and type as well as the ultimate limit state. According to calculation and analysis, the overall resistance of X52 9.5mm pipe is higher than that of X60 8.7mm pipe, except for the equal resistance against excavation and puncture by a third party. This is especially true in regard to the ultimate tensile strain and compression strain, increasing by 17% and 31% respectively. By adopting the Monte Carlo method using certain parameters about pipe material, construction and operational maintenance, the failure probability of X52 and X60 pipes under corrosion as well as excavation and puncture by a third party is calculated and analyzed quantitatively. The result shows that the failure probability of X52, 9.5mm pipe is 2.61 ×10−4 times per kilometer per year which is much less than that of X60 8.7mm pipe (5.50 ×10−4 times per kilometer per year). Considering the safe reliability of pipeline, the X52 9.5mm pipe scheme is far superior to X60 8.7mm pipe scheme. Therefore the former scheme is recommended for design which only increases the cost by 1.5%.

Study on Statistical Parameters of Resistance of Steel Highway Bridge Reliability Design in China

2010 ◽  
Vol 163-167 ◽  
pp. 3324-3327 ◽  
Author(s):  
Kun Li
Keyword(s):  
Design Method ◽  
Limit State ◽  
Highway Bridges ◽  
Calculation Model ◽  
Highway Bridge ◽  
Statistical Parameters ◽  
Probability Limit ◽  
Reliability Design ◽  
Structure Reliability ◽  
Bridge Reliability

The coming national specification for steel highway bridge will adopt the design method of probability limit state based on the structure reliability theory. Then the statistical parameters of loads and resistance play a key role in this method. Based on the extensive survey and investigation on site, the parameters of resistance are calculated in the study. In the work, three aspects of resistance’s uncertainty which are the uncertainty of materials properties, geometric parameters of members and calculation model are analyzed respectively. Then, the statistical parameters of five typical members of two commonly used steels—Q235q and Q345qD—in steel highway bridges are calculated. The recommended statistical parameters of resistance of steel highway bridge can be a reference for the new specification.

scholarly journals A RATIONALIZED SEISMIC DESIGN METHOD FOR BUILDINGS IN EARTHQUAKE-PRONE DEVELOPING COUNTRIES

2021 ◽  
Vol 11 (4) ◽  
pp. 266-279
Author(s):  
Tint Lwin ◽  
Takeshi Koike ◽  
Ji Dang
Keyword(s):  
Developing Countries ◽  
Seismic Design ◽  
Design Method ◽  
Limit State ◽  
Design Procedure ◽  
Ultimate Limit State ◽  
Design Guideline ◽  
Seismic Safety ◽  
Seismic Design Method ◽  
Ultimate Limit

In general, the US codes such as the UBC-97 and ASCE-7 are widely used in developing countries including Myanmar, Syria, Philippines and so on. When the current seismic design guideline based on the UBC-97 and ACI 318-99 in Myanmar is assessed, several problems can be found in the following items: firstly, the fundamental period is not checked in modeling; secondly, reduction factor R is introduced a priori for the base shear estimation. And finally, a limit state assessment is done only for Design Basic Earthquake (DBE) but not for other design earthquakes. As a result, adequate yield strength is not checked for Maximum Operational Earthquake (MOE). Then there is no way to assess the seismic safety of the ultimate limit state for Maximum Considered Earthquake (MCE). In order to solve these problems, a rationalized seismic design method for earthquake prone developing countries is proposed. A new seismic design method is developed for MOE and MCE with adequate yield acceleration and typical period of the building estimated by using pushover analysis. A simplified procedure to estimate the inelastic response for a given design spectrum is also proposed. Finally, this design procedure can provide a rational method to assess the seismic safety for the ultimate limit of the building.

DESIGN OF BOLTED CONNECTIONS SUBJECT TO TORSION AND SHEAR IN THE ULTIMATE LIMIT STRESS STATE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohamed S. Abu-Yosef ◽  
Ezzeldin Y. Sayed-Ahmed ◽  
Emam A. Soliman
Keyword(s):  
Failure Modes ◽  
Focal Point ◽  
Design Method ◽  
Limit State ◽  
Bending Moment ◽  
Steel Structures ◽  
Ultimate Limit State ◽  
Shear Forces ◽  
Limit States ◽  
Ultimate Limit

Steel connections transferring axial and shear forces in addition to bending moment and/or torsional moment are widely used in steel structures. Thus, design of such eccentric connections has become the focal point of any researches. Nonetheless, behavior of eccentric connections subjected to shear forces and torsion in the ultimate limit state is still ambiguous. Most design codes of practice still conservatively use the common elastic analysis for design of the said connections even in the ultimate limit states. Yet, there are some exceptions such as the design method proposed by CAN/CSA-S16-14 which gives tabulated design aid for the ultimate limit state design of these connections based on an empirical equation that is derived for ¾ inch diameter A325 bearing type bolts and A36 steel plates. It was argued that results can also be used with a margin of error for other grade bolts of different sizes and steel of other grades. As such, in this paper, the performance of bolted connection subject to shear and torsion is experimentally investigated. The behavior, failure modes and factors affecting both are scrutinized. Twelve connections subject to shear and torsion with different bolts configurations and diameters are experimentally tested to failure. The accuracy of the currently available design equations proposed is compared to the outcomes of these tests.

Gear Reliability Design Using Probability Finite Element Method Based on Response Surface

2010 ◽  
Vol 34-35 ◽  
pp. 7-12 ◽  
Author(s):  
Shu Xia Sun ◽  
Ming Yan ◽  
Ping Bai ◽  
Li Han
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Response Surface ◽  
Design Method ◽  
Limit State ◽  
General Purpose ◽  
State Function ◽  
Limit State Function ◽  
Reliability Design ◽  
Element Method

The paper studies on the gear reliability design method using probability finite element method based on response surface and it indicates that the reliability sensibility calculation method of function in response surface can be used when limit state function is unknown. The limit state function established on response function is quadratic polynomial with simple form and it makes the calculation of variance and deviation very convenient, which realizes the simple and easy calculation of reliability sensitivity and largely increases calculation velocity and precision. The method can be applied for general purpose with certain standard, which is easy for programming and accomplishing gear reliability design in a rapid and precise way.

Reliability-Based Scheme Design for Fault-Crossing of X90 Pipeline

2014 ◽  
Vol 1030-1032 ◽  
pp. 2601-2607
Author(s):  
Yu Qing Liu ◽  
Zhen Yong Zhang ◽  
Kai Wen
Keyword(s):  
Failure Probability ◽  
Oil And Gas ◽  
Theoretical Foundation ◽  
Design Method ◽  
Influence Factors ◽  
Steel Grade ◽  
Pipeline Transportation ◽  
Long Distance ◽  
Reliability Design ◽  
Scheme Design

While high steel grade X70, X80 pipeline has been widely used in long-distance oil and gas pipeline engineering of China, to further improve steel grade to X90 is an effective way to increase the efficiency of pipeline transportation and reduce construction cost. In this paper, the failure probability of earthquake fault crossing of X90 pipeline has been calculated with the strain-based reliability design method and the design scheme has been adjusted according to sensitivity analysis with influence factors of the failure probability of fault-crossing of X90 pipeline, after that the scheme of fault-crossing of X90 pipeline which meets requirements of pipeline reliability has been figured out. This study has laid a theoretical foundation for the application of X90 pipeline in future construction of pipeline engineering.

scholarly journals RELIABILITY ANALYSIS OF THE LATERAL TORSIONAL BUCKLING RESISTANCE AND THE ULTIMATE LIMIT STATE OF STEEL BEAMS WITH RANDOM IMPERFECTIONS

2015 ◽  
Vol 21 (7) ◽  
pp. 902-911 ◽  
Author(s):  
Zdeněk Kala
Keyword(s):  
Failure Probability ◽  
Limit State ◽  
Ultimate Limit State ◽  
Safety Factors ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Random Variability ◽  
Partial Safety Factors ◽  
Ultimate Limit

The paper deals with the analysis of reliability of a hot-rolled steel IPE-beam designed according to Eurocodes. A beam at its ultimate limit state is considered. The load acting on the beam consists of permanent and long-term single variation actions. The beam is loaded with end bending moments about the major principal axis. The beam is susceptible to lateral torsional buckling between the end supports. Reliability of the beam is assessed using probabilistic analysis based on the Monte Carlo method. Failure probability is a function of the random variability of the loadcarrying capacity and the random variability of load effects. The variability of the load-carrying capacity is influenced by the variability of initial imperfections. Imperfections are considered according to experimental research. Numerical studies showed that the failure probability is significantly misaligned. High values of failure probability were obtained for slender beams, for beams loaded only by permanent load action, and for beams loaded only by long-term single variation load. In further studies the values of partial safety factors of load and resistance were calibrated so that the failure probability had a target value of 7.2E–5. Relatively high values of partial safety factors were obtained especially for beams with high slenderness.

Considering Catenary Action in Designing End-Restrained Steel Beams in Fire

2005 ◽  
Vol 8 (3) ◽  
pp. 309-324 ◽  
Author(s):  
H. X. Yu ◽  
J. Y. Richard Liew
Keyword(s):  
Design Method ◽  
Load Capacity ◽  
Limit State ◽  
Beam Deflection ◽  
Steel Beams ◽  
Ultimate Limit State ◽  
Ultimate Load Capacity ◽  
Element Analysis ◽  
Catenary Action ◽  
In Fire

When a building compartment is subjected to fire attack, there are complex interactions between the fire affected members with the surrounding members. The behaviour of the steel frame members in fire can be drastically different from that of its member in isolation. This paper studies the behaviour of steel beams with the increase of temperature from beam action phase to catenary action phase and until failure. The load bearing mechanism in the catenary action phase is discussed and the failure criterion is defined. A new ultimate limit state based on 15% maximum strain of steel material at elevated temperature is proposed to determine the ultimate load capacity of beams failed in the catenary action phase. Wide ranges of beam parameters including various beam sizes and span lengths with different degrees of end restraints are studied. Comparison of results with those obtained from nonlinear finite element analysis shows that the proposed design method could enhance the critical temperature of steel beams by over 200 °C if proper attention is given to the integrity of connections to resist the catenary force. In this respect, methods to estimate the catenary force and beam deflection are provided.

Reliability Design of Footings in Cohesionless Soils using Soft Computing Metamodelings

2016 ◽  
pp. 442-464
Author(s):  
Anthony T. C. Goh ◽  
Wengang Zhang
Keyword(s):  
Bearing Capacity ◽  
Soft Computing ◽  
Model Building ◽  
Limit State ◽  
Multivariate Adaptive Regression Splines ◽  
Ultimate Limit State ◽  
Cohesionless Soils ◽  
Reliability Design ◽  
Reliability Based Design ◽  
Adaptive Regression Splines

An extensive database of full-scale field load tests was used to build predictive models to determine the bearing capacity of footings under axial compression in cohesionless soils. Based on this database, soft computing techniques, i.e., the multivariate adaptive regression splines (MARS) and artificial neural networks (ANN) are adopted for comparison for surrogate model building on bearing capacity. The performances of the two computing techniques are compared. A reliability-based design of footings was then presented. It allows one to obtain the probability that the ultimate limit state was exceeded for a given soil variability.

Reliability Analysis of Mooring Lines of Floating Structures Under Corrosion and Material Degradation

2020 ◽  
Author(s):  
Ricardo Soares Gomes Junior ◽  
Paulo Mauricio Videiro ◽  
Paulo de Tarso Themistocles Esperança ◽  
Luis Volnei Sudati Sagrilo
Keyword(s):  
Reliability Analysis ◽  
Failure Probability ◽  
Limit State ◽  
Gas Production ◽  
Ultimate Limit State ◽  
Offshore Structure ◽  
Material Degradation ◽  
Mooring Lines ◽  
Piecewise Constant Model ◽  
Over Time

Abstract This paper presents a procedure for reliability analysis of mooring lines of floating units for oil and gas production considering corrosion and material degradation over time. The proposed procedure is limited to the ultimate limit state (ULS) and considers mooring lines made up of chain and polyester rope segments, although the same methodology can be applied to cases with steel wire segments. The proposed procedure can also be applied for mooring lines connected to any other type of floating offshore structure. For reliability assessments, it is necessary to consider the distributions and the probabilistic aspects of the random variables involved in the process. The weakest link system is used to model the strength of a mooring line segment. Simplified time-dependent probabilistic models for chain corrosion and polyester degradation are adopted to predict the strength degradation over time. The annual failure probability for different years is estimated by approximating the degraded strength by a piecewise constant model in order to perform a time variant reliability analysis. Monte Carlo simulations are used to determine the failure probability. A study case is also presented, where annual extreme top tension is obtained from long-term statistics considering Brazilian offshore environmental conditions acting on a turret moored floating, production, storage and offloading unit (FPSO).

Development of Reliability-Based Criteria for Corrosion Assessment

2018 ◽  
Author(s):  
Riski Adianto ◽  
Maher Nessim ◽  
Dongliang Lu
Keyword(s):  
Failure Probability ◽  
Limit State ◽  
Assessment Criteria ◽  
Ultimate Limit State ◽  
Operating Pressure ◽  
Safety Factors ◽  
Limit States ◽  
Feature Based ◽  
Corrosion Assessment ◽  
Ultimate Limit

Reliability-based corrosion assessment criteria were developed for onshore natural gas and low vapor pressure (LVP) pipelines as part of a joint industry project. The criteria are based on the limit states design (LSD) approach and are designed to achieve consistent safety levels for a broad range of pipeline designs and corrosion conditions. The assessment criteria were developed for two corrosion limit states categories: ultimate limit state, representing large leaks and ruptures; and leakage limit state, representing small leaks. For the ultimate limit state, a safety class system is used to characterize pipelines based on the anticipated severity of failure consequences as determined by pressure, diameter, product, population density and environmental sensitivity. Since the leakage limit state does not result in significant safety or environmental consequences, a single reliability target, applicable for all pipelines at all locations is used. The assessment criteria formulations are characterized by three elements: the equations used to calculate the characteristic demand (i.e. operating pressure) and capacity (i.e. burst pressure resistance at a corrosion feature); the characteristic values of the key input parameters for these formulas (such as diameter, pressure and feature depth); and the safety factors defining the characteristic demand as a ratio of characteristic capacity. The process used to calibrate safety factors and characteristic input parameter values that meet the desired reliability levels is described, and an assessment of the accuracy and consistency of the resulting checks in meeting the reliability targets is included. The assessment criteria include two methods of application: feature-based and section-based. The feature-based method divides the allowable failure probability equally between all features. It is simple to use, but conservative in nature. It is suitable for pipelines with a small number of corrosion features. The section-based method considers the failure probability of the corrosion features in a pipeline section as a group, and ensures that the total group failure probability is below the allowable threshold for the section. This method produces less conservative results than the feature-based method, but it requires more detailed calculations. It is suitable for all pipelines, and is particularly useful for those with a large number of features. The practical implications of the application of these criteria are described in the companion paper IPC2018-78608 Implementation of Reliability-based Criteria for Corrosion Assessment.

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