Design of the PMXL-1 Platform

2009 ◽  
Author(s):  
Vitor G. Maciel ◽  
Luiz H. M. Alves
Keyword(s):  
Large Diameter ◽  
Concept Development ◽  
Central Core ◽  
Wave Crest ◽  
Structural Elements ◽  
Functional Requirements ◽  
Design Load ◽  
Campos Basin ◽  
Weight Lift ◽  
Analogous Functional

This paper presents the design of the Mexilha˜o-1 Platform (PMXL-1), located at Brazilian Santos Basin, focusing in the concept development and design of the light weight optimized jacket. PXML-1 is a gas and condensate production hub platform with 525 MMscf/d processing capacity and 18350 metric tons (mton) topside design load. Installed in 172m water depth, is the deepest fixed production unit in Brazil. Jacket concept was developed aiming to structural and functional optimization, based on previous company work on Campos Basin. Due to height, top and base dimensions and expected weight, lift option was discarded and a 4-leg launched and self upended jacket was selected. To increase structural efficiency, bracing was provided by fewer but larger diameter and heavier walled members. Launch trusses, with conventional bay spans, form a central core that is used also to support risers, I-tubes and other appurtenances. Face bays are double spanned, X-braced, with central cross nodes stabilized by members connected to the central core. Horizontal levels have no peripheral members and are double X-braced. Top horizontal frame level is located above operational wave crest, reducing environmental loads, and bottom level is elevated about 6m from mudline. Topside modules are directly supported by jacket main legs and two additional dummy legs, eliminating a module support frame. Foundation is provided by eight large diameter vertical skirt piles. Comparison with PNA-2, a conventional 8-leg platform, installed about 20 years ago in Campos Basin, in similar environmental conditions, with analogous functional requirements, shows considerable advantages and savings. In comparison to PNA-2, PMXL-1 jacket weight is reduced by 32% and pile weight is reduced by 65%. Number of structural elements and tubular connections to be fabricated and erected is also drastically reduced.

Energy Absorbability of Large Scale Inflatable Composite Structures

2006 ◽  
Author(s):  
Claudia Quigley ◽  
Karen Buehler ◽  
Paul Cavallaro ◽  
Ali Sadegh
Keyword(s):  
Composite Structures ◽  
Large Scale ◽  
Scaling Laws ◽  
Structural Elements ◽  
Functional Requirements ◽  
Test Procedures ◽  
Governmental Agencies ◽  
Sufficient Energy ◽  
Strength And Stiffness ◽  
Energy Absorbing

Airbeams, inflatable composite structures, have traditionally been used solely as structural elements. Modeling and test procedures have been under development by academia, industry and governmental agencies to predict and evaluate an airbeam's structural properties. However, the pneumatic component that gives airbeams their strength and stiffness also provides airbeams the capability to absorb energy. Test procedures and scaling laws that can be used to evaluate the energy absorbing capacity of these structural elements will be described and evaluated. Test data will show that airbeams can reliably absorb sufficient energy for applications such as a pneumatic fender and meet other functional requirements. The paper will also describe textile considerations and other material properties that will enable this application to be successful.

scholarly journals The concept and implementation of an energy retaining wall of large diameter piles

2020 ◽  
Vol 205 ◽  
pp. 06007
Author(s):  
Octavian Bujor ◽  
Iulia Prodan ◽  
Augustin Popa ◽  
Horia Ban
Keyword(s):  
Slope Failure ◽  
Residential Buildings ◽  
Retaining Wall ◽  
Large Diameter ◽  
Structural Elements ◽  
Heating And Cooling ◽  
Energy Piles ◽  
Urban Energy ◽  
Implementation Stages

Performance and success of energy geostructures systems are already facts proven by research and practice. The number of implementations is in constant grow and due to their advantages, such systems have started to be implemented in a variety of structural elements. Among the various types, energy piles are the most common type of energy geostructures. However, most of the existing research, experimental sites and case studies refer to energy piles as a foundation element. This paper presents the concept and implementation steps of a different type of energy piles system which is a retaining wall of piles built in Cluj-Napoca, Romania. The paper is based on a real project case study, where large diameter piles are used as retaining wall for an urban excavation on a steep slope with high slope failure potential. The piles from the retaining system have been energy equipped in order to be used as an energy exchange element with the ground for heating and cooling demand of 3 new residential buildings from the same site. The paper will present the concept of an urban energy retaining wall and implementation stages of the project.

Performance of composites versus metals under extreme loading

2017 ◽  
Vol 8 (1) ◽  
pp. 86-108
Author(s):  
Gregory Szuladziński
Keyword(s):  
Related Problem ◽  
Mass Density ◽  
Dynamic Buckling ◽  
Structural Elements ◽  
Numerical Examples ◽  
Design Load ◽  
Simulation Results ◽  
The Difference

Most structures, including airframes, are designed using quasi-static criteria. With this approach, composites are superior to metals, as they are stronger and have a smaller mass density. This article addresses a question of the remaining margins of safety when the loads are outside the design envelope, be they in magnitude or in character. The answers are provided first for some simple panels, and then for a selected airliner wing. In each case, the items compared are designed using the same design load. A related problem of dynamic buckling is addressed in detail and it is explained how it may lead to great destructive power of slender structural elements. The difference in performance between metals and composites, in that regard, is addressed. A few numerical examples and simulation results are provided.

scholarly journals Application of Axiomatic Design principles in conceptual design

2018 ◽  
Vol 223 ◽  
pp. 01008 ◽  
Author(s):  
Josipa Delaš ◽  
Stanko Škec ◽  
Mario Štorga
Keyword(s):  
Conceptual Design ◽  
Evaluation Process ◽  
Axiomatic Design ◽  
Design Principles ◽  
Concept Development ◽  
Independence Axiom ◽  
Functional Requirements ◽  
Information Axiom ◽  
Concept Evaluation ◽  
Insight Into

The main objective of this paper is to propose a modified methodology for concept evaluation by applying Axiomatic Design principles. Several drawbacks were recognised during the literature review and application of established Axiomatic Design principles that limit its use for concept evaluation. These drawbacks include the lack of analysis of concepts that violate the Independence Axiom, the application to concepts that are not generated with Axiomatic Design and inclusion of constraints and requirements in the evaluation process. The proposed methodology consists of four steps of which the first one is to analyse the compliance of concepts with a set of functional requirements. Afterwards, to determine the possible violation of the Independence Axiom, non-diagonal elements need to be examined and reangularity and semiangularity values calculated for each concept. Finally, concepts are evaluated in terms of Information Axiom to include requirements, criteria and constraints other than functional requirements. Applying Information Axiom to all concepts regardless of Independence Axiom violation provides insight into the complexity of concepts. The proposed methodology was applied to mobility scooter conceptual design conducted in cooperation with an industrial partner. The partner company provided input and system constraints at the beginning of the project and guidelines for concept development. Constraints were taken into consideration by applying the Information Axiom in which constraints are compared with values measured on prototypes.

Analyses of a Large Diameter Steel Lazy Wave Riser for Ultra Deepwater in Campos Basin

2004 ◽  
Author(s):  
Ricardo Franciss ◽  
Elton Ribeiro
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Water Depth ◽  
Large Diameter ◽  
Static And Dynamic Analysis ◽  
Deep Waters ◽  
Campos Basin ◽  
Allowable Level ◽  
Rigid Line ◽  
Oil Export

Petrobras is going deeper and some fields are feasible only if the production platforms are installed in ultra deep waters, close to the wells. In one case in Campos Basin, for example, the platform will be installed at 1255 m water depth and the solution to allow the production is based on the evolution of flexible lines for high pressure and high loads. For the oil export line, however, a steel rigid line was chosen, due to the large diameter. Some analyses were performed in order to make it feasible the installation of an 18-inch SCR export oil line. Due to fatigue loads, the free hanging catenary configuration did not match with API RP 2RD recommendations, so Petrobras decided to change the original shape to Lazy Wave in order to reduce the top loads and increase the fatigue life. But, some configurations are not feasible to install. High angles close to the installation vessel or high stresses close to the flotation segments are some problems that must be solved. This article will present the steps made to reach a configuration that will make feasible the installation of this riser, in parallel to the static and dynamic analysis, to maintain the stresses in an allowable level, in accordance with API RP 2RD.

Rock Berm Design for Pipeline Stability

2012 ◽  
Author(s):  
David J. Chamizo ◽  
Dean R. Campbell ◽  
Eric P. Jas ◽  
Jay R. Ryan
Keyword(s):  
Traditional Approach ◽  
Large Diameter ◽  
Mechanical Damage ◽  
Small Scale ◽  
Lateral Movement ◽  
Functional Requirements ◽  
Natural Gas Pipelines ◽  
Hydrodynamic Loading ◽  
Wave Heights ◽  
Subsea Pipelines

Stabilizing large diameter natural gas pipelines on the seabed against extreme hydrodynamic loading conditions has proven to be challenging in the northwest of Australia. Tropical storms, which affect the area annually between November and April, can generate wave heights exceeding 30 m and storm steady state currents of 2 m/s or more. Consequently, in shallow water depths, typically less than 40–60 m, subsea pipelines can be subjected to very high hydrodynamic loads, potentially causing significant lateral movement. To mitigate the risk of the pipeline suffering mechanical damage due to excessive lateral movement, quarried and graded rock is often dumped over the pipeline as a secondary stabilization solution. In order to satisfy functional requirements, the rock berm must comprise of a sufficiently large rock grading size and berm volume to withstand the design hydrodynamic loading such that the pipeline cannot break out of the berm. The design of rock berms for pipeline secondary stabilization has traditionally followed a deterministic approach that uses empirical equations for preliminary rock sizing, followed by small-scale physical modeling for design verification and optimization. Whilst the traditional approach can be effective in producing a robust rock berm design, opportunities for further optimization are inhibited by a lack of available data and an imperfect understanding of the failure mechanisms. This paper presents an overview of an improved approach for rock berm design optimization. A general overview of rock berms, the design principles, benefits and risks are also presented.

scholarly journals Analysis of G+5 Storeys Building With and Without Floating Column

2021 ◽  
Vol 889 (1) ◽  
pp. 012008
Author(s):  
S K Singh ◽  
Sarv Priya ◽  
Mohd Nadeem ◽  
Md Badar Alam
Keyword(s):  
Structural Parameters ◽  
Horizontal Displacement ◽  
Rigid Base ◽  
Structural Elements ◽  
Functional Requirements ◽  
Structural Behaviour ◽  
Current Period ◽  
Rigid Frame ◽  
Earthquake Load ◽  
Shear Demand

Abstract In current period, several structures are being planned and built with structural complicatedness like building with floating columns on different floors and spaces. The buildings accompanying floating columns are extremely detrimental that is constructed in earthquake-prone regions. The current study analyses and compare the buildings with and without of floating column. The columns which are directly supported by a beam without any rigid base are known as floating columns. Various buildings have been constructed with floating columns in India. Typically, it is required to provide larger spacing between the columns to entertain the requirements of parking or reception lobbies. Some of the functional requirements of a building might be satisfied by providing the floating columns but the structural behaviour of the building changes abruptly. The beams that supported the floating columns require more flexure and shear demand than the surrounding beams. In addition, it leads to stiffness unevenness at a specific joint. Columns are the main structural elements that resist the lateral load in a rigid frame and have the importance in the performance of the building under earthquake load The storey’s stuffiness below the floating column is normally reduced. Therefore, an attempt has been made to analyse the performance of a G+5 storey building with and without floating columns and compare structural parameters such as horizontal displacement, storey drift and storey shear under seismic excitation using (ETABS) Software.

Ulcerogenic Tumors of the Pancreas

1968 ◽  
Vol 26 ◽  
pp. 186-187
Author(s):  
J. C. Garancis ◽  
J. F. Kuzma ◽  
S. D. Wilson ◽  
E. H. Ellison
Keyword(s):  
Endoplasmic Reticulum ◽  
Tumor Cells ◽  
Islet Cell ◽  
Disease Process ◽  
Central Core ◽  
Islet Cell Tumors ◽  
Opaque Zone ◽  
Granular Form ◽  
Zollinger Ellison Syndrome

It has been proposed that a gastrin-like hormone elaborated by non-beta islet tumors of the pancreas may be responsible for a fulminating ulcer diathesis. Subsequently, a potent gastric secretagogue was isolated from ulcerogenic tumors of the pancreas. This disease process is known now as “Zollinger-Ellison syndrome”.In our studies of two cases of Zollinger-Ellison syndrome, pancreatic lesions were identified as alpha islet cell tumors (Fig. 1). Tumor cells were fairly uniform. The sizes of the alpha granules were not significantly different, but their number and distribution varied greatly from one cell to another. Each granule consisted of a round, highly dense central core, separated from the limiting membrane by an opaque zone. The granular form of the endoplasmic reticulum was particularly prominent. Numerous mitochondria, round or elongated, were dispersed throughout the cytoplasm. Individual or clusters of lysosomes were observed in the majority of cells.

Development of a digital SEM

1991 ◽  
Vol 49 ◽  
pp. 358-359
Author(s):  
A. Yamada ◽  
A. Shibano ◽  
K. Harasawa ◽  
T. Kobayashi ◽  
H. Fukuda ◽  
...  
Keyword(s):  
Large Diameter ◽  
Objective Lens ◽  
Large Specimen ◽  
Backscattered Electrons ◽  
Digital Scanning ◽  
Junction Type ◽  
High Resolution Images ◽  
Working Distance ◽  
Type Detector ◽  
Short Working

A newly developed digital scanning electron microscope, the JSM-6300, has the following features: Equipped with a narrower conical objective lens (OL), it allows high resolution images to be obtained easily at a short working distance (WD) and a large specimen tilt angle. In addition, it is provided with automatic functions and digital image processing functions for ease of operation.Conical C-F lens: The newly developed conical C-F objective lens, having low aberration characteristics over a wide WD range, allows a large-diameter (3-inch) specimen to be tilted up to 60° at short WD, and provides images with low magnifications starting at 10*. On the bottom of the lens, a p n junction type detector is provided to detect backscattered electrons (BE) from the specimen. As the narrower conical 0L increases the secondary electron (SE) detector's field intensity on the specimen surface, high SE image quality is obtained.

Structural phenomena in the growth of carbon nanotubes

1993 ◽  
Vol 51 ◽  
pp. 750-751
Author(s):  
Jun Jiao
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Carbonaceous Material ◽  
Cluster Growth ◽  
Structural Elements ◽  
Rich Variety ◽  
Different Shapes ◽  
Point To Point

HREM studies of the carbonaceous material deposited on the cathode of a Huffman-Krätschmer arc reactor have shown a rich variety of multiple-walled nano-clusters of different shapes and forms. The preparation of the samples, as well as the variety of cluster shapes, including triangular, rhombohedral and pentagonal projections, are described elsewhere.The close registry imposed on the nanotubes, focuses attention on the cluster growth mechanism. The strict parallelism in the graphitic separation of the tube walls is maintained through changes of form and size, often leading to 180° turns, and accommodating neighboring clusters and defects. Iijima et. al. have proposed a growth scheme in terms of pentagonal and heptagonal defects and their combinations in a hexagonal graphitic matrix, the first bending the surface inward, and the second outward. We report here HREM observations that support Iijima’s suggestions, and add some new features that refine the interpretation of the growth mechanism. The structural elements of our observations are briefly summarized in the following four micrographs, taken in a Hitachi H-8100 TEM operating at an accelerating voltage of 200 kV and with a point-to-point resolution of 0.20 nm.

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