Investigation of Impact of New Design Code on Riser System Design

2009 ◽  
Author(s):  
Alan Yu ◽  
Paul Stanton ◽  
Yongming Cheng
Keyword(s):  
System Design ◽  
Production Systems ◽  
Design Code ◽  
Finite Element Program ◽  
Stress Evaluation ◽  
Element Program ◽  
Steel Catenary Risers ◽  
Ease Of Access ◽  
The Impact ◽  
Gas Lift

Top tensioned risers are fluid conduits from subsea equipment to surface floating production platforms. The advantages of using top tensioned risers are the ability to drill and complete through the production riser, ease of access of the production trees for gas lift operation, and the simplicity of workover and redrill. The integrity of a riser system plays an important role in deepwater developments. Top tensioned risers (TTRs) and steel catenary risers (SCRs) have been widely used with floating production systems such as Spars and TLPs. API RP 2RD [1] has been used to guide riser system design for the last decade. API RP 2RD is being revised as a code (ISO 13628-12) that will also be adopted as a new API code. This paper investigates the impacts of the new design code on the riser system design. This paper first discusses the differences between ISO/WD 13628-12 and the existing API RP 2RD code, particularly the section on design criteria for pipes. The Holstein top tensioned riser system is chosen as an example to evaluate the riser system design impacts. The risers have been installed and successfully producing oil since 2005. The results of the nonlinear finite element program ABAQUS used to analyze the Holstein top tensioned risers were evaluated according to the API RP 2RD. The same analytical results are used for evaluating the impact of the proposed ISO 13628-12 in the area of stress evaluation.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Simplified Stress Linearization Method, Maintaining Accuracy

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Andrzej T. Strzelczyk ◽  
Mike Stojakovic
Keyword(s):  
Limit Analysis ◽  
Linearization Method ◽  
Finite Element Program ◽  
Stress Evaluation ◽  
Primary Stress ◽  
Stress Classification ◽  
Stress Components ◽  
3D Elements ◽  
Element Program ◽  
Axisymmetric Structure

ASME PVP Code stress linearization is needed for assessment of primary and primary-plus-secondary stresses. The linearization process is not precisely defined by the Code; as a result, it may be interpreted differently by analysts. The most comprehensive research on stress linearization is documented in the work of Hechmer and Hollinger [1998, “3D Stress Criteria Guidelines for Application,” WRC Bulletin 429.] Recently, nonmandatory recommendations on stress linearization have been provided in the Annex [Annex 5.A of Section VIII, Division 2, ASME PVP Code, 2010 ed., “Linearization of Stress Results for Stress Classification.”] In the work of Kalnins [2008, “Stress Classification Lines Straight Through Singularities” Proceedings of PVP2008-PVT, Paper No. PVP2008-61746] some linearization questions are discussed in two examples; the first is a plane-strain problem and the second is an axisymmetric analysis of primary-plus secondary stress at a cylindrical-shell/flat-head juncture. The paper concludes that for the second example, the linearized stresses produced by Abaqus [Abaqus Finite Element Program, Version 6.10-1, 2011, Simulia Inc.] diverge, therefore, these linearized stresses should not be used for stress evaluation. This paper revisits the axisymmetric analysis discussed by Kalnins and attempts to show that the linearization difficulties can be avoided. The paper explains the reason for the divergence; specifically, for axisymmetric models Abaqus inconsistently treats stress components, two stress components are calculated from assumed formulas and all other components are linearized. It is shown that when the axisymmetric structure from Kalnins [2008, “Stress Classification Lines Straight Through Singularities” Proceedings of PVP2008-PVT, Paper No. PVP2008-61746] is modeled with 3D elements, the linearization results are convergent. Furthermore, it is demonstrated that both axisymmetric and 3D modeling, produce the same and correct stress Tresca stress, if the stress is evaluated from all stress components being linearized. The stress evaluation, as discussed by Kalnins, is a primary-plus-secondary-stresses evaluation, for which the limit analysis described by Kalnins [2001, “Guidelines for Sizing of Vessels by Limit Analysis,” WRC Bulletin 464.] cannot be used. This paper shows how the original primary-plus-secondary-stresses problem can be converted into an equivalent primary-stress problem, for which limit analysis can be used; it is further shown how the limit analysis had been used for verification of the linearization results.

The Finite Element Analysis of Dynamic Interaction of High-Speed Shinkansen, the Rail, and Bridge

1993 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Response Analysis ◽  
Element Formulation ◽  
Element Analysis ◽  
Finite Element Program ◽  
The Finite Element Analysis ◽  
Element Program ◽  
The Impact

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.

Predicting the Impact of Quenching on Mechanical Properties of Complex-Shaped Aluminum Alloy Parts

1995 ◽  
Vol 117 (2) ◽  
pp. 479-488 ◽  
Author(s):  
D. D. Hall ◽  
I. Mudawar
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Boundary Conditions ◽  
Finite Element Program ◽  
Part Geometry ◽  
Heat Treated ◽  
Element Program ◽  
Nozzle Configuration ◽  
The Impact

The mechanical properties of age-hardenable aluminum alloy extrusions are critically dependent on the rate at which the part is cooled (quenched) after the forming operation. The present study continues the development of an intelligent spray quenching system, which selects the optimal nozzle configuration based on part geometry and composition such that the magnitude and uniformity of hardness (or yield strength) is maximized while residual stresses are minimized. The quenching of a complex-shaped part with multiple, overlapping sprays was successfully modeled using spray heat transfer correlations as boundary conditions within a finite element program. The hardness distribution of the heat-treated part was accurately predicted using the quench factor technique; that is, the metallurgical transformations that occur within the part were linked to the cooling history predicted by the finite element program. This study represents the first successful attempt at systematically predicting the mechanical properties of a quenched metallic part from knowledge of only the spray boundary conditions.

Analysis on Axial Compression Ratio to Strong Column Weak Beam Effect in Framework Node

2014 ◽  
Vol 578-579 ◽  
pp. 16-19
Author(s):  
Xin Wen ◽  
Ze Jing Hao ◽  
Xing Guo Wang
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Pressure Ratio ◽  
Finite Element Program ◽  
Static State ◽  
Axial Compression Ratio ◽  
Weak Beam ◽  
Element Program ◽  
The Impact

Nodes of Column ends, included ordinary Intermediate nodes and nodes in the model of carbon fiber, have been established based on finite element program, have analyzed the comparison of the deformation, bearing capacity, ductility in Quasi static state under three conditions of axial compression ratio reinforcement (0.2, 0.4, 0.6) between reinforcement nodes and ordinary nodes, have researched the impact caused by the change of axial pressure ratio on seismic performance of node, The result have shown that size of the axial compression ratio and bearing capacity of reinforced nodes follow basic plastics performance, but ductility of nodes in low axial compression ratio is more effective.

Property determination and wave propagation in a block of Barre granite

1977 ◽  
Vol 67 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Werner Goldsmith ◽  
J. L. Sackman ◽  
R. L. Taylor
Keyword(s):  
Wave Propagation ◽  
Finite Element Program ◽  
In Situ Calibration ◽  
Propagation Analysis ◽  
Principal Axes ◽  
Element Program ◽  
Principal Directions ◽  
Calibration Techniques ◽  
Barre Granite ◽  
The Impact

abstract The principal axes of a 666.8 by 609.6 by 489.0 mm (2614 in by 24 in by 1914 in) block of Barre granite, treated as an orthotropic elastic material were determined from measured pulse velocities along directions connecting 160 pairs of surface points, encompassing the entire spectrum of possible orientations. The elastic moduli of the rock were ascertained by Hopkinson bar tests involving rods cored from other samples along their principal directions; this was required for the execution of a wave-propagation analysis in the block treated as a half-space. Construction and insertion techniques were developed for transducers to be embedded in the rock at 14 locations. External and internal calibration procedures were devised to permit interpretation of the data transmitted from the interior of the sample. Transients in the block were generated by the impact of 6.35-mm (14 in) diameter steel spheres on loading bars sandwiching a thin quartz disk, serving as an input transducer, against the specimen. The wave patterns sensed by the transducers were displayed and photographed on oscillographic screens. A finite element program capable of handling arbitrary anisotropy was developed and employed for comparing the experimental results with analytical predictions based on the measured input as the boundary condition. For those stations where computations were performed, the correlation ranged from good to qualitative. It is concluded that better transducer embedment and in situ calibration techniques are required for internal transducers used in hard rocks of this type.

New Design Configuration of Steel Catenary Risers With Pull-Tube for Spars

2011 ◽  
Author(s):  
Shan Shi ◽  
Charlie Mao ◽  
Jenny Yang ◽  
Nishu Kurup
Keyword(s):  
Finite Element ◽  
Finite Element Program ◽  
Additional Advantage ◽  
Nonlinear Contact ◽  
Element Program ◽  
Steel Catenary Risers ◽  
Bending Loads ◽  
A Current ◽  
Water Depths ◽  
Over Time

In previous Spar designs where pull tubes were used to board the risers (either export or flowline risers), the pull-tube extended a considerable distance beyond the keel and used a tapered design to form a bend restrictor that supported the riser throughout the riser/hull interface. In a current Spar design, the pull-tube is terminated at the hull keel and the bending loads are carried by a double sided stress-joint in the riser that pivots on a centralizer located near the bottom of the pull-tube. Essentially, this is an adaptation of the double-sided stress joint used for top tensioned risers exiting the bottom of their buoyancy can stems to the similar condition of an SCR exiting a pull tube terminating at the Spar’s keel. This new pull-tube and SCR configuration can be applied for both Truss and Classic Spars. SCRs boarding Spars through pull tubes have several advantages over stress joints or flex-joints anchored in porches, notably, eliminating both the need for divers to make large piping connections at 500′ to 600′ water depths and the possibility of those connections leaking over time. Moving the bend restrictor function from the pull tube to the riser provides the additional advantage of adding flexibility for the Spar to accommodate future risers whose size and weight are not known at the time the pull tubes are designed and the platform is installed. With the stress joint as part of the riser, the bend restrictor can be custom designed for each riser since the pull tube works the same for all risers. The SCR and stress joint, pull-in and in-place analyses have been performed by using the finite element program ABAQUS. The nonlinear capabilities of ABAQUS including the hybrid, gap and contact element formulations are utilized in the analysis of the pull-in process. The nonlinear contact elements with finite sliding capability are modeled with an exponential over-closure relationship.

scholarly journals A numerical parametric study on the efficiency of prestressed geogrid reinforced soil

2020 ◽  
Vol 205 ◽  
pp. 12004
Author(s):  
Soukat Kumar Das ◽  
N. K. Samadhiya
Keyword(s):  
Energy Requirement ◽  
Reinforced Soil ◽  
Shallow Foundation ◽  
Finite Element Program ◽  
Load Bearing ◽  
Total Input ◽  
Ground Conditions ◽  
Element Program ◽  
Numerical Parametric Study ◽  
The Impact

Prestressing geosynthetics offers a rapid and safe method of improving the poor ground conditions. This paper aims to find out the effect of prestressing the geogrid layer on load bearing and settlement performance. This study also takes into account the impact of the size, depth of placement and the adjacency of footing, for unreinforced (UR), geogrid reinforced (GR) and prestressed geogrid reinforced (PGR) soil on the load-bearing and the settlement characteristics by using the finite element program Plaxis 3D. Based on numerical simulation, it appears that PGR soil can enhance the bearing pressure of the UR soil by almost 500% and reduced the settlement by nearly 88 % by reducing the energy consumption. The footing placed at higher depths for PGR soil gives better performance as compared to GR soil. Moreover, placing two adjacent square footing increases the interference zone of PGR soil by 67% as compared to UR soil. This method can be instrumental in reducing the total input energy requirement to achieve a certain settlement during placement of shallow foundation for various important structures while being economic simultaneously.

scholarly journals Simultaneous Influence of the Track Axis Curvature and the Support Line Obliquity at Railway Bridge Superstructures with Steel Beams Embedded in Concrete

2018 ◽  
Vol 7 (2) ◽  
pp. 77-90
Author(s):  
Stănescu Răzvan Marian ◽  
Stan Oana Mihaela
Keyword(s):  
Program Analysis ◽  
Steel Beams ◽  
Support Line ◽  
Design Code ◽  
Technical Literature ◽  
Finite Element Program ◽  
Railway Bridges ◽  
Bridge Superstructures ◽  
Element Program ◽  
Simultaneous Influence

Abstract For new railway bridges with small spans (L ≤ 35.00 m) superstructures with steel beams embedded in concrete are recommended and used, which can ensure the requirements of strength and especially stiffness, regardless of velocity. In all the design prescriptions used so far for superstructures with steel beams embedded in concrete, and even in the technical literature, there is little information and data on the influence of the support line obliquity and the track axis curvature in the design and calculation of these types of structures. In the design code, if certain conditions related to the geometry of the superstructure are met (obliquity, curvature) the calculation is a simplified one, made on a single isolated longitudinal beam of the deck; otherwise, if the conditions are not met, finite element program analysis is recommended. The article aims to study the situations in which the requirements of the design prescriptions are not met.

Computer Simulation of Dynamic Impact Processes: A Visual and Audio Presentation

1991 ◽  
Author(s):  
Wing L. Cheng ◽  
Alan Craig ◽  
Ilhan Dilber
Keyword(s):  
Numerical Approach ◽  
Scientific Data ◽  
Finite Element Program ◽  
Impact Processes ◽  
3D Geometry ◽  
Element Program ◽  
Tremendous Amount ◽  
The Impact ◽  
Impact Events ◽  
Dynamic Phenomena

Abstract Complicated dynamic phenomena as occurred in high velocity impact processes were studied using a numerical approach. A transient nonlinear finite element program was used to model and simulate the impact events. The use of supercomputers was required in these simulations due to the size of the problem and the duration of the events. Techniques designed to visualize 3D geometry as well as scientific data were developed to help researchers make sense out of the tremendous amount of data generated by the supercomputers. Resulting animation sequences provided a means to the researchers to study these dynamic processes. A newly developed technique called data sonification was also exploited to provide an additional medium to display scientific data. This is accomplished by mapping various parameters of the dataset to various parameters of sound. Two complex 3D numerical examples were used to demonstrate both visual and sonic techniques.

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