Structural Digital Twin of FPSO for Monitoring the Hull and Topsides Based on Inspection Data and Load Measurement

2021 ◽  
Author(s):  
Shankar Bhat ◽  
Varadarajan Nadathur ◽  
David Knezevic ◽  
Pieter Aalberts ◽  
Hans Kolsters ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Reduced Basis ◽  
Element Analysis ◽  
Digital Twin ◽  
Detailed Structural Analysis ◽  
Physical Sensor ◽  
Day To Day Operations ◽  
Inspection Data ◽  
Lifecycle Management ◽  
Operational Data

Abstract A high-fidelity FPSO Structural Digital Twin (SDT) based on Reduced Basis Finite Element Analysis (RB-FEA) coupled with inspection data and physical sensor measurements (advisory hull monitoring system) is presented to demonstrate a complete FPSO "digital thread" that combines operational data feeds, detailed structural analysis based on as-is asset condition, and automated structural integrity reporting. This lays the groundwork for a philosophical shift for asset lifecycle management by enabling the use of "as-measured" conditions in lieu of assumed "design-conditions" for a more accurate, and robust understanding of asset health. We demonstrate the deployment of this methodology for the Bonga FPSO and discuss the value that it brings during day-to-day operations.

Application of Laser Profilometry for Fitness-for-Service Assessment on Pressure Vessel External Corrosion

2012 ◽  
Author(s):  
Grant Nelson ◽  
Ian Bradley ◽  
Martin Fingerhut ◽  
Deli Yu
Keyword(s):  
Pressure Vessel ◽  
Structural Integrity ◽  
Element Analysis ◽  
Level 3 ◽  
Ultrasonic Techniques ◽  
Laser Profilometry ◽  
External Corrosion ◽  
Inspection Data ◽  
Integrity Analysis

In order to safely extend the life of damaged in-service components, Fitness-For-Service (FFS) assessments are used to evaluate structural integrity. These FFS assessments largely depend upon the quality of the inspection data. Compared to traditional inspection methods such as pit gauge or ultrasonic techniques, laser profilometry provides faster results with higher resolution and accuracy. Improved inspection data enables more precise FFS assessments and leads to fewer unnecessary repairs and non-conservative assessments. This paper examines how laser profilometry measurements were taken of several corrosion areas on the exterior shell of a pressure vessel in order to complete a FFS assessment equivalent to an API 579 Level 2 assessment. The results of the FFS assessment show how laser profilometry data may be used in a detailed structural integrity analysis to consider a vessel safe for continued use. A discussion of how laser profilometry data could also be used for an API 579 Level 3 assessment, using finite element analysis, in areas not acceptable for Level 1, or 2 assessments is included.

Tire Bead Overheating in Urban Buses and Trucks Using Drum Brake Systems

1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Energy ◽  
Structural Integrity ◽  
Experimental Temperature ◽  
Temperature Profiles ◽  
Element Analysis ◽  
Drum Brake ◽  
Fea Model

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

scholarly journals Computational and experimental mechanical performance of a new everolimus-eluting stent purpose-built for left main interventions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saurabhi Samant ◽  
Wei Wu ◽  
Shijia Zhao ◽  
Behram Khan ◽  
Mohammadali Sharzehee ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Mechanical Performance ◽  
Experimental Studies ◽  
Patient Specific ◽  
Wall Structure ◽  
Left Main ◽  
Element Analysis ◽  
Stent Expansion ◽  
Radial Strength ◽  
Different Diameters

AbstractLeft main (LM) coronary artery bifurcation stenting is a challenging topic due to the distinct anatomy and wall structure of LM. In this work, we investigated computationally and experimentally the mechanical performance of a novel everolimus-eluting stent (SYNERGY MEGATRON) purpose-built for interventions to large proximal coronary segments, including LM. MEGATRON stent has been purposefully designed to sustain its structural integrity at higher expansion diameters and to provide optimal lumen coverage. Four patient-specific LM geometries were 3D reconstructed and stented computationally with finite element analysis in a well-validated computational stent simulation platform under different homogeneous and heterogeneous plaque conditions. Four different everolimus-eluting stent designs (9-peak prototype MEGATRON, 10-peak prototype MEGATRON, 12-peak MEGATRON, and SYNERGY) were deployed computationally in all bifurcation geometries at three different diameters (i.e., 3.5, 4.5, and 5.0 mm). The stent designs were also expanded experimentally from 3.5 to 5.0 mm (blind analysis). Stent morphometric and biomechanical indices were calculated in the computational and experimental studies. In the computational studies the 12-peak MEGATRON exhibited significantly greater expansion, better scaffolding, smaller vessel prolapse, and greater radial strength (expressed as normalized hoop force) than the 9-peak MEGATRON, 10-peak MEGATRON, or SYNERGY (p < 0.05). Larger stent expansion diameters had significantly better radial strength and worse scaffolding than smaller stent diameters (p < 0.001). Computational stenting showed comparable scaffolding and radial strength with experimental stenting. 12-peak MEGATRON exhibited better mechanical performance than the 9-peak MEGATRON, 10-peak MEGATRON, or SYNERGY. Patient-specific computational LM stenting simulations can accurately reproduce experimental stent testing, providing an attractive framework for cost- and time-effective stent research and development.

Casing Design for an Oxygen Concentrator

1999 ◽  
Author(s):  
Stephanie H. Swindle ◽  
Beth A. Todd ◽  
James F. Cuttino
Keyword(s):  
Quality Of Life ◽  
Structural Integrity ◽  
Chronic Obstructive ◽  
Gas Mixture ◽  
Improve Quality ◽  
Chronic Obstructive Pulmonary Disorder ◽  
Element Analysis ◽  
Pulmonary Disorder ◽  
Oxygen Concentrator

Abstract Human bodies depend on a steady flow of oxygen for the heart and lungs. When a person has Chronic Obstructive Pulmonary Disorder (COPD), a device called an oxygen concentrator can be used to improve quality of life. An oxygen concentrator is an electrically powered device that takes in room air and converts it to an oxygen rich gas mixture suitable for breathing. Although a few models are battery powered, oxygen concentrators are not easily portable because they are bulky and weigh between 25–50 lbs. In this study, components were identified for re design to reduce the overall weight of the device. For instance, the concentrator casing was identified as its heaviest component. Using finite element analysis, changes in wall thickness and dimensions can be investigated to reduce weight while maintaining structural integrity. By reducing the weight of the casing, the oxygen concentrator will be easier to transport.

A Hybrid Topside Structural Approach to the Management of Aging Fleet

2021 ◽  
Author(s):  
Biramarta Isnadi ◽  
Luong Ann Lee ◽  
Sok Mooi Ng ◽  
Ave Suhendra Suhaili ◽  
Quailid Rezza M Nasir ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Metal Loss ◽  
Web Based ◽  
Strong Basis ◽  
Asset Risk ◽  
Risk Ranking ◽  
Design Life ◽  
Industry Standards ◽  
Integrity Management ◽  
Inspection Data

Abstract The objective of this paper is to demonstrate the best practices of Topside Structural Integrity Management for an aging fleet of more than 200 platforms with about 60% of which has exceeded the design life. PETRONAS as the operator, has established a Topside Structural Integrity Management (SIM) strategy to demonstrate fitness of the offshore topside structures through a hybrid philosophy of time-based inspection with risk-based maintenance, which is in compliance to API RP2SIM (2014) inspection requirements. This paper shares the data management, methodology, challenges and value creation of this strategy. The SIM process adopted in this work is in compliance with industry standards API RP2SIM, focusing on Data-Evaluation-Strategy-Program processes. The operator HSE Risk Matrix is adopted in risk ranking of the topside structures. The main elements considered in developing the risk ranking of the topside structures are the design and assessment compliance, inspection compliance and maintenance compliance. Effective methodology to register asset and inspection data capture was developed to expedite the readiness of Topside SIM for a large aging fleet. The Topside SIM is being codified in the operator web-based tool, Structural Integrity Compliance System (SICS). Identifying major hazards for topside structures were primarily achieved via data trending post implementation of Topside SIM. It was then concluded that metal loss as the major threat. Further study on effect of metal loss provides a strong basis to move from time-based maintenance towards risk-based maintenance. Risk ranking of the assets allow the operator to prioritize resources while managing the risk within ALARP level. Current technologies such as drone and mobile inspection tools are deployed to expedite inspection findings and reporting processes. The data from the mobile inspection tool is directly fed into the web based SICS to allow reclassification of asset risk and anomalies management.

Critical Flaw Size Evaluation in Butt-Fusion Joints of HDPE Pipes

2014 ◽  
Author(s):  
S. Kalyanam ◽  
P. Krishnaswamy ◽  
E. M. Focht ◽  
D.-J. Shim ◽  
F. W. Brust ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Nuclear Industry ◽  
Flaw Size ◽  
Fusion Process ◽  
Pipe Material ◽  
Element Analysis ◽  
Hdpe Pipe ◽  
Asme Code ◽  
Critical Flaw ◽  
Pipe Joints

The integrity of high density polyethylene (HDPE) piping and fusion joints are a topic of interest to the nuclear industry, regulators, ASME code, and the plastics pipe industry. The ASME Code Case N-755-1 has been approved and addresses the use of HDPE in safety related applications. Over the last few years some of the concerns identified with the parent HDPE pipe material and the fusion joints have been addressed while others are still being resolved. One such unresolved concern is the effect of the fusion process on the integrity of the joint, specifically, the introduction of flaws during the fusion process. The potential impact of flaws in the fusion joint on the service life of the HDPE piping is being evaluated. The current study calculates stress intensity factors (SIF) for circumferential flaws and uses them to evaluate the potential structural integrity of HDPE fusion joints in pipes. The recent API 579-1/ASME FFS-1 standard provides SIF (KI) solutions to various semi-elliptical and full-circumferential (360°) surface cracks/flaws on the outer surface (OD) and the inner surface (ID). The API 579-1/ASME FFS-1 standard SIF tables and finite element analysis (FEA) of selected cases were used to develop simplified SIF relations for full-circumferential surface flaws that can be used for plastic pipes with diameters ranging from 101.6 mm (4 inch) through 914.4 mm (36 inch) and dimensional ratios (DRs) from 7 through 13. Further, the SIF of embedded flaws akin to lack-of-fusion regions was evaluated. The results from this study serve as precursors to understanding and advancing experimental methods to address important issues related to the critical tolerable flaw size in the butt-fusion joint material and were utilized to select the specimen tests and hydrostatic pipe tests used to evaluate various joining processes. Further, they will help with understanding the essential variables that control the long-term component integrity and structural performance of HDPE pipe joints in ASME Class 3 nuclear piping.

scholarly journals Finite Element Analysis Study on Lattice Structure Fabricated Using Corn Husk Fibre Reinforced Recycled Polystyrene Composite

2021 ◽  
Vol 335 ◽  
pp. 03011
Author(s):  
Mohammed Shariff Mohamed Sulaiman ◽  
Seong Chun Koay ◽  
Ming Yeng Chan ◽  
Hui Leng Choo ◽  
Ming Meng Pang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Integrity ◽  
Lattice Structure ◽  
Lattice Parameter ◽  
Triangular Prism ◽  
Hexagonal Prism ◽  
Element Analysis ◽  
Corn Husk ◽  
Fea Simulation

This research investigated the lattice structure fabricated using corn husk fibre reinforced recycled polystyrene composite using Finite Element Analysis (FEA). The material’s properties of this composite material were obtained from previous study. Then, the lattice structure of lattice structure was created using Creo® software and the FEA simulation was done by ANSYS software. In this study, the lattice structures were created using triangular prism and hexagonal prism. The analysis was divided into two conditions: 1) lattice structure with different prism shape and similar surface area, 2) lattice structure with varies of strut thickness and 3) lattice structure with different prism shape and similar lattice parameter. The results show the lattice structure with triangular prism have more structural integrity than hexagonal prism. Then, lattice structure with triangular prism can be built with lesser material but stronger and stiffer than lattice structure with hexagonal prism.

Case Study of Model-Based Inversion of the Angle Beam Ultrasonic Response From Composite Impact Damage

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
John Wertz ◽  
Laura Homa ◽  
John Welter ◽  
Daniel Sparkman ◽  
John C. Aldrin
Keyword(s):  
Inverse Problem ◽  
Surrogate Model ◽  
Composite Structures ◽  
Impact Damage ◽  
Gaussian Process Regression ◽  
Model Based ◽  
Shadowed Region ◽  
Inspection Data ◽  
Ultrasound Inspection ◽  
Lifecycle Management

The U.S. Air Force seeks to improve lifecycle management of composite structures. Nondestructive characterization of damage is a key input to this framework. One approach to characterization is model-based inversion of ultrasound inspection data; however, the computational expense of simulating the response from damage represents a major hurdle for practicality. A surrogate forward model with greater computational efficiency and sufficient accuracy is, therefore, critical to enable damage characterization via model-based inversion. In this work, a surrogate model based on Gaussian process regression (GPR) is developed on the chirplet decomposition of the simulated quasi-shear scatter from delamination-like features that form a shadowed region within a representative composite layup. The surrogate model is called in the solution of the inverse problem for the position of the hidden delamination, which is achieved with <0.5% error in <20 min on a workstation computer for two unique test cases. These results demonstrate that solving the inverse problem from the ultrasonic response is tractable for composite impact damage with hidden delaminations.

A Hybrid Shape Optimization Method Based on Implicit Differentiation and Node Removal Techniques

1993 ◽  
Author(s):  
P. Y. Shim ◽  
S. Mannoochehri
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Design Methodology ◽  
Structural Integrity ◽  
Boundary Elements ◽  
Programming Algorithm ◽  
Element Analysis ◽  
Node Removal ◽  
Removal Technique

Abstract This paper presents a hybrid shape optimal design methodology using an implicit differentiation approach for sensitivity analysis and a node removal technique for shape alteration. The approach presented attempts to overcome the weaknesses inherent in each individual technique. The basic idea is to combine the sensitivity analysis, which forms the analytical basis for the algorithm, and a node removal technique, which grossly modifies the shape without the need for a remeshing after each iteration. The sensitivity analysis is based on the finite element equilibrium equation and the implicit differentiation technique. It examines the effect positional changes of the boundary nodes have on the stress values. Using the sensitivity results, a sequential linear programming algorithm is utilized to determine optimum positions of the boundary nodes. These optimization results are provided as inputs to an algorithm that decides which boundary nodes should be removed. By removing boundary nodes, the boundary elements change to either a triangular or a non-existent type. This shape modification procedure starts from the boundary elements and moves toward the internal elements. Only two iterations of finite element analysis are required to modify one boundary layer. To maintain the structural integrity and the connectivity of the elements in the model, a connectivity check is performed after each iteration. Three design examples are given to illustrate the accuracy and the steps involved in the proposed optimal design methodology.

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