Anisotropic Material Characterization and its Effect on Structural Integrity

2016 ◽  
Author(s):  
Oliver Hilgert ◽  
Christoph Kalwa
Keyword(s):  
Yield Strength ◽  
Anisotropic Material ◽  
Bending Moment ◽  
Structural Behavior ◽  
Burst Pressure ◽  
Transverse Strain ◽  
Pipe Material ◽  
Strain Capacity ◽  
Parametric Studies ◽  
Critical Buckling Strain

In recent years anisotropic pipe material properties have gained more interest due to offshore; strain based design and fracture arrest topics. The effect of anisotropic UOE pipe material characteristic is analyzed in this contribution. Both, anisotropic strain dependent values (Lankford) and anisotropic strength dependent factors (Hill) are compared, and their impact on load bearing and plastic strain capacity is investigated. Several common load cases as internal and external pressure as well as bending are investigated. An analysis of the structural behavior concerning burst pressure and transverse strain capacity, collapse pressure, maximum bending moment and critical buckling strain is performed depending on yield strength variation. Therefore the above load and strain capacities are investigated based on present material anisotropy as well as numerical parametric studies. For the internal pressure as dominating load case, it was found that a higher yield strength in the longitudinal direction decreases burst pressure and increases transverse strain capacity. An increase of radial yield strength increases burst pressure as well as transverse strain capacity. For collapse applications, higher radial and transverse yield strength is beneficial as well as a lower longitudinal yield strength. Increasing longitudinal and radial yield strength leads to beneficial structural responses in terms of bending. Increase of transversal yield strength is thus not recommended as the maximum bending moment is not affected and critical buckling strain is decreased. Further it becomes clear from the above various parametric studies that the structural behavior is prone to differ for every set of distinct anisotropic parameters and the load cases. On the other hand selection of distinct anisotropic material can promote the desired structural behavior.

Influence of Yield Strength Variability over Cross-Section to Steel Beam Load-Carrying Capacity

2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala
Keyword(s):  
Yield Strength ◽  
Cross Section ◽  
Carrying Capacity ◽  
Bending Moment ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Variability ◽  
Hot Rolled ◽  
Hot Rolled Steel

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.

A Justification for Designing and Operating Pipelines Up to Stresses of 80% SMYS

2002 ◽  
Author(s):  
Martin McLamb ◽  
Phil Hopkins ◽  
Mark Marley ◽  
Maher Nessim
Keyword(s):  
Yield Strength ◽  
Oil And Gas ◽  
Large Diameter ◽  
Pipe Material ◽  
Gas Pipelines ◽  
Long Distance ◽  
Remote Locations ◽  
Pass Through ◽  
The Impact ◽  
Minimum Yield

Oil and gas majors are interested in several projects worldwide involving large diameter, long distance gas pipelines that pass through remote locations. Consequently, the majors are investigating the feasibility of operating pipelines of this type at stress levels up to and including 80% of the specified minimum yield strength (SMYS) of the pipe material. This paper summarises a study to investigate the impact upon safety, reliability and integrity of designing and operating pipelines to stresses up to 80% SMYS.

Study of the Sensitivity of the Guanabara Bay PE-3 Pipeline to Geometric Imperfections

2004 ◽  
Author(s):  
Adilson Carvalho Benjamin ◽  
Joa˜o Nisan Correia Guerreiro ◽  
Rita de Ca´ssia Carvalho Silva ◽  
Abimael Fernando Dourado Loula
Keyword(s):  
Yield Strength ◽  
Maximum Temperature ◽  
Maximum Pressure ◽  
Pipe Material ◽  
Guanabara Bay ◽  
Pressure Loading ◽  
Geometric Imperfections ◽  
Von Mises ◽  
Von Mises Stresses

This paper describes the study performed to investigate the sensitivity of the Guanabara Bay PE-3 pipeline to geometric imperfections. The main results of several FE analyses are presented. It is concluded that the PE-3 zigzag pipeline is geometrically stable when submitted to the maximum pressure loading and maximum temperature loading established in the design. Also it is shown that the von Mises stresses calculated in the analyses were below the yield strength of the pipe material.

Safety of Pipelines Subjected to Deterioration Processes Modeled Through Dynamic Bayesian Networks

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
O. G. Palencia ◽  
A. P. Teixeira ◽  
C. Guedes Soares
Keyword(s):  
Bayesian Networks ◽  
Safety Assessment ◽  
Oil And Gas ◽  
Design Method ◽  
Dynamic Bayesian Networks ◽  
Burst Pressure ◽  
Probabilistic Framework ◽  
Empirical Formulas ◽  
Model Predictions ◽  
Parametric Studies

This paper studies the application of Dynamic Bayesian Networks (DBNs) for modeling degradation processes in oil and gas pipelines. A DBN tool consisting of a matlab code has been developed for performing inference on models. The tool is then applied for probabilistic modeling of the burst pressure of a pipe subjected to corrosion degradation and for safety assessment. The burst pressure is evaluated using the ASME B31G design method and other empirical formulas. A model for corrosion prediction in pipelines and its governing parameters are explicitly included into the probabilistic framework. Different sets of simulated corrosion measurements are used to increase the accuracy of the model predictions. Several parametric studies are conducted to investigate how changes in the observed corrosion (depth and length) and in the frequency of inspections affect the pipe reliability.

Safety of Pipelines Subjected to Deterioration Processes Modelled Through Dynamic Bayesian Networks

2017 ◽  
Author(s):  
O. G. Palencia ◽  
A. P. Teixeira ◽  
C. Guedes Soares
Keyword(s):  
Bayesian Networks ◽  
Safety Assessment ◽  
Oil And Gas ◽  
Design Method ◽  
Dynamic Bayesian Networks ◽  
Burst Pressure ◽  
Probabilistic Framework ◽  
Empirical Formulas ◽  
Model Predictions ◽  
Parametric Studies

The paper studies the application of Dynamic Bayesian Networks for modelling degradation processes in oil and gas pipelines. A DBN tool consisting of a Matlab code has been developed for performing inference on models. The tool is then applied for probabilistic modelling of the burst pressure of a pipe subjected to corrosion degradation and for safety assessment. The burst pressure is evaluated using the ASME B31G design method and other empirical formulas. A model for corrosion prediction in pipelines and its governing parameters are explicitly included into the probabilistic framework. Different sets of simulated corrosion measurements are used to increase the accuracy of the model predictions. Several parametric studies are conducted to investigate how changes in the observed corrosion (depth and length) and in the frequency of inspections affect the pipe reliability.

Anisotropy: Benefits for UOE Line Pipe

2012 ◽  
Author(s):  
Oliver Hilgert ◽  
Steffen Zimmermann ◽  
Christoph Kalwa
Keyword(s):  
Anisotropic Material ◽  
Isotropic Material ◽  
Three Dimensional ◽  
Structural Response ◽  
Bending Moment ◽  
Yield Function ◽  
Material Behavior ◽  
Load Case ◽  
Line Pipe ◽  
Anisotropic Plastic

Plastic anisotropic material behavior of UOE line pipe is investigated in view of its structural response. Common load cases are considered and their resultant strain capacity concerning Strain Based Design demands are discussed. Hill’s yield function is used to analyze steel line pipe under internal pressure and bending moment. Here, a three-dimensional anisotropic plastic strain evolution is considered. It was shown, that underlying anisotropic material behavior can be beneficial for the structural response of line pipe, although it depends on the load case and the directional anisotropy. That is in some way contrary to the demands in specifications, where isotropic material behavior is desired.

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.

scholarly journals Linear Matching Method for Parametric Studies of Weldments Creep-Fatigue Endurance

2013 ◽  
Author(s):  
Yevgen Gorash ◽  
Haofeng Chen
Keyword(s):  
Bending Moment ◽  
Evaluation Procedure ◽  
Geometrical Parameters ◽  
Matching Method ◽  
Individual Parameter ◽  
Creep Fatigue ◽  
Parametric Studies ◽  
Fatigue Evaluation ◽  
Fatigue Endurance ◽  
Linear Matching Method

This paper presents parametric studies on creep-fatigue endurance of the steel AISI type 316N(L) weldments defined as types 1, 2 and 3 according to R5 Vol. 2/3 Procedure classification at 550°C. The study is implemented using the Linear Matching Method (LMM) and based upon previously developed creep-fatigue evaluation procedure considering time fraction rule. Several geometrical configurations of weldments with individual parameter sets, representing different fabrication cases, are developed. For each of configurations, the total number of cycles to failure N* in creep-fatigue conditions is assessed numerically for different loading cases. The obtained set of N* is extrapolated by the analytic function dependent on normalised bending moment M̃, dwell period Δt and geometrical parameters. Proposed function for N* shows good agreement with numerical results obtained by the LMM. Therefore, it is used for the identification of Fatigue Strength Reduction Factors (FSRFs) intended for design purposes and dependent on proposed variable parameters.

Structural Behavior of RC Cylinders Confined with High Strength Transverse Reinforcement

2010 ◽  
Vol 163-167 ◽  
pp. 1321-1324
Author(s):  
Sang A. Cha ◽  
Cho Hwa Moon ◽  
Sang Woo Kim ◽  
Kil Hee Kim ◽  
Jung Yoon Lee
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Yield Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Structural Behavior ◽  
Transverse Reinforcement ◽  
Strength Concrete ◽  
High Rise ◽  
Compressive Strength Of Concrete

The number of high-rise reinforced concrete (RC) buildings is steadily increasing since 1980’s. The use of high strength concrete is indispensible for high-rise RC construction to ensure sufficient strength of the structure. The effect of high strength concrete can be significantly improved by the use of high strength and large size reinforcing bars. The yield strength of transverse reinforcement is limited in the current design codes to prevent possible sudden concrete failure due to over reinforcement. This paper presents the effects of the yield strength of transverse reinforcement and compressive strength of concrete on the structural behavior of reinforced concrete cylinders. Two parameters were considered in this investigation: compressive strength of concrete and the yield strength of transverse reinforcement (472MPa, 880MPa, and 1,430 MPa). Analytical and experimental results indicated that the structural behavior of RC cylinders confined with high strength transverse reinforcement is strongly influenced by compressive strength of concrete.

scholarly journals Experimental analysis of the structural behavior of different types of shear connectors in steel-concrete composite beams

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Juliano Geraldo Ribeiro Neto ◽  
Gregório Sandro Vieira ◽  
Rogers de Oliveira Zoccoli
Keyword(s):  
Bending Moment ◽  
Experimental Tests ◽  
Composite Beams ◽  
Structural Behavior ◽  
Steel Beams ◽  
Shear Connectors ◽  
Reinforced Concrete Slabs ◽  
Different Types ◽  
Composite Section ◽  
Hot Rolled

ABSTRACT: The present work aims to compare the structural behavior of steel-concrete composite-section beams for three types of shear connectors made of U hot rolled section and cold-formed sections of U and L. Experimental tests were performed with the three types of connectors associated with I section laminated steel beams and reinforced concrete slabs. For each type of connector, three push-out tests were performed, as well as six simple supported beam tests to evaluate the positive bending moment region. The results indicated that the direct shear behavior among the different types of connectors presents significant differences, however they do not significantly influence the average flexural strength of the composite beams. These, however, present considerable differences in deflections and deformations due to the stiffness differences of the connectors.

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