Local Buckling of Buried HDPE Pipelines Subjected to Earthquake Faulting: Case Study Via Numerical Simulations and Experimental Testing

Abstract Guidance for determining a S-N based fatigue capacity (safe life design) for preloaded connectors is included in Section 5.4 of the 2019 edition of DNVGL-RP-C203 (C203-2019). This section includes guidance on the finite element model representation, finite element based fatigue analysis and determination of the connector design fatigue capacity by use of one of the following methods: Method 1 by FEA based fatigue analysis, Method 2 by FEA based fatigue analysis and experimental testing and Method 3 by full-scale connector fatigue testing. The FEA based fatigue analysis makes use of Appendix D.2 in C203-2019 (“S-N curves for high strength steel applications for subsea”). Practical use of Section 5.4 is illustrated with a case study of a fatigue tested wellhead profile connector segment test. Further developments of Section 5.4 of C203-2019 are proposed. This included acceptance criteria for use of a segment test to validate the FEA based fatigue analysis of a full-scale preloaded connector.

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Crashworthiness Performance of Mass-Efficient Extruded Structures

Transportation: Making Tracks for Tomorrow’s Transportation ◽

10.1115/imece2002-39077 ◽

2002 ◽

Cited By ~ 1

Author(s):

Robert R. Mayer ◽

Weigang Chen ◽

Anil Sachdev

Keyword(s):

Numerical Simulations ◽

Single Cell ◽

Experimental Testing ◽

Experimental Studies ◽

Nonlinear Material ◽

Dynamic Strain ◽

Cell Design ◽

Explicit Finite Element ◽

The One ◽

Crushing Behavior

Theoretical, numerical and experimental studies were conducted on the axial crushing behavior of traditional single-cell and innovative four-cell extrusions. Two commercial aluminum alloys, 6061 and 6063, both with two tempers (T4 and T6), were considered in the study. Testing coupons taken from the extrusions assessed the nonlinear material properties. A theoretical solution was available for the one-cell design, and was developed for the mean crushing force of the four-cell section. Numerical simulations were carried out using the explicit finite element code LS-DYNA. The aluminum alloy 6063T4 was found to absorb less energy than 6061T4, for both the one-cell and four-cell configurations. Both 6061 and 6063 in the T6 temper were found to have significant fracture in the experimental testing. Theoretical analysis and numerical simulations predicted a greater number of folds for the four-cell design, as compared to the one-cell design, and this was confirmed in the experiments. The theoretical improvement in energy absorption of 57% for the four-cell in comparison with the one-cell design was confirmed by experiment. The good agreement between the theoretical, numerical and experimental results allows confidence in the application of the theoretical and numerical tools for both single-cell and innovative four-cell extrusions. It was also demonstrated that these materials have very little dynamic strain rate effect.

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Local Buckling in end Expansion of Subsea Pipelines

Jurnal Teknologi ◽

10.11113/jt.v69.3268 ◽

2014 ◽

Vol 69 (7) ◽

Author(s):

Jaswar Koto ◽

Abd. Khair Junaidi ◽

M. H. Hashim

Keyword(s):

Crude Oil ◽

Axial Force ◽

Oil And Gas ◽

Local Buckling ◽

Offshore Platform ◽

Offshore Pipeline ◽

Specific Rule ◽

Subsea Pipelines ◽

Study Development

Offshore pipeline is mainly to transport crude oil and gas from offshore to onshore. It is also used to transport crude oil and gas from well to offshore platform and from platform to another platform. The crude oil and gas horizontally flows on the seabed, and then vertically flows inside the riser to the offshore platform. One of current issues of the oil and gas transportation system is an end expansion caused by the axial force. If the end expansion occurs over it limit can cause overstress to riser. This paper explores the effect of axial force toward local buckling in end expansion. In the study, development of programming in visual basic 2010 firstly was constructed using empirical equation. The programming code, then, was validated by comparing simulation result with actual data from company. As case study, the end expansion for various thicknesses of pipes was simulated. In this programming, DNV regulation is included for checking either design complied or not with regulation. However, DNV regulation doesn’t have specific rule regarding the end expansion but it is evaluated under load displacement control under strain condition.

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Structural Assessment of the Hull Response of an FPSO Unit to Dropped Objects: A Case Study

Polish Maritime Research ◽

10.2478/pomr-2019-0064 ◽

2019 ◽

Vol 26 (4) ◽

pp. 39-46 ◽

Cited By ~ 1

Author(s):

Ozgur Ozguc

Keyword(s):

Structural Damage ◽

Local Buckling ◽

Structural Response ◽

Offshore Structures ◽

Mechanical Equipment ◽

Structural Members ◽

Impact Area ◽

Explicit Dynamic ◽

The Impact

Abstract Offshore structures are exposed to the risk of damage caused by various types of extreme and accidental events, such as fire, explosion, collision, and dropped objects. These events cause structural damage in the impact area, including yielding of materials, local buckling, and in some cases local failure and penetration. The structural response of an FPSO hull subjected to events involving dropped objects is investigated in this study, and non-linear finite element analyses are carried out using an explicit dynamic code written LS-DYNA software. The scenarios involving dropped objects are based on the impact from the fall of a container and rigid mechanical equipment. Impact analyses of the dropped objects demonstrated that even though some structural members were permanently deformed by drop loads, no failure took place in accordance with the plastic strain criteria, as per NORSOK standards. The findings and insights derived from the present study may be informative in the safe design of floating offshore structures.

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Dynamic Response of a Road Bridge Subjected to Passing a Heavy Vehicle over a Standard Irregularity - Numerical Modelling and Experimental Testing

Communications - Scientific letters of the University of Zilina ◽

10.26552/com.c.2022.1.d37-d45 ◽

2022 ◽

Vol 24 (1) ◽

pp. D37-D45

Author(s):

Milan Moravčík

Keyword(s):

Numerical Modelling ◽

Dynamic Response ◽

Numerical Simulations ◽

Experimental Testing ◽

Heavy Vehicle ◽

Dynamic Effects ◽

Actual Problem ◽

Box Girder ◽

Dynamic Excitation ◽

Girder Bridge

The paper presents an analysis of an actual problem related to dynamic effects to road bridges due to travelling a heavy vehicle over the bridge. Numerical simulations of the dynamic response are applied on a fictitious simple beam of the length Lb = 52 m with an artificial irregularity at midspan, corresponding to a characteristic span L (b5) = 52 m of the ten-span continuous box girder bridge. A heavy four-axle truck m v = 32 t is used for dynamic excitation, travelling over the bridge at passing speed of 70km / h. The obtained results are compared to results of the experimentally tested ten-span continuous pre-stressed reinforced concrete girder bridge at the same speed.

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Deflection Analysis of Sleeve Jointed Purlin Systems with Non-Linear Rotational Stiffness

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.147.66 ◽

2011 ◽

Vol 147 ◽

pp. 66-69 ◽

Cited By ~ 4

Author(s):

Chang J. Wang ◽

Diane J. Mynors ◽

Tertia Morgan ◽

Brian Cartwright

Keyword(s):

Numerical Simulation ◽

Linear Relationship ◽

Experimental Testing ◽

Rotational Stiffness ◽

Non Linear ◽

Deflection Analysis

Sleeved purlin systems are usually used in roof constructions. A non-linear relationship between the bolt hole extension and the load transferred to the bolt was derived with experimental testing and numerical simulation. Consequently, the non-linear rotational stiffness of sleeved joints was derived based on the configuration of sleeves in this paper. The procedure for calculating the deflection of purlin systems with non-linear rotational stiffness at the joints is presented. The analysis and calculation of the deflection is demonstrated through a case study.

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Effect of Axial Gap between Diffuser Inlet and Impeller on Efficiency and Flow Pattern of Centrifugal Fans

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.446-447.621 ◽

2013 ◽

Vol 446-447 ◽

pp. 621-625

Author(s):

Mojtaba Gholamian ◽

Gurram Krishna Mohan Rao ◽

Bhramara Panitapu

Keyword(s):

Numerical Simulations ◽

Flow Pattern ◽

Squirrel Cage ◽

Centrifugal Fans ◽

And Performance

Inlet is one of the basic elements of squirrel cage fan that can have great effect on performance and losses, especially between inlet exit and first section of impeller width. In this paper the effect of axial gap between inlet diffuser and impeller on performance and flow pattern is considered. Three diffuser inlet sizes with respect to impeller size (smaller, nearly same and bigger than inner impeller diameter) and three axial gaps within the available dimensions of the casing and impeller were chosen. Numerical simulations were performed to find the effect of this axial gap on flow pattern, performance and efficiency. From the simulation of each case study, flow pattern and its mechanism and the causes that affecting the efficiency and performance due to axial gap are analyzed and presented.

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