Eulerian Finite Element Formulation for Sloshing Response of Floating Roofs in Aboveground Storage Tanks

Author(s):  
Shoichi Yoshida ◽  
Kazuyoshi Sekine ◽  
Tsukasa Mitsuta

The floating roofs are widely used to prevent evaporation of content in large aboveground oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to the floating roofs due to liquid sloshing. The structural integrity of the floating roofs for the sloshing is urgent issue to establish in petrochemical and oil refining industries. This paper presents the axisymmetric finite element analysis for the sloshing response of floating roofs in cylindrical storage tanks. The hydrodynamic coupling of fluid and floating roof under seismic excitation is taken into consideration in the analysis. It is assumed that the fluid is incompressible and inviscid, and the roof is linear elastic while the sidewall and the bottom are rigid. The theory for the finite element analysis in which the behavior of the fluid is formulated in terms of dynamic pressure as the Eulerian approach is developed. The basic vibration characteristics of the floating roof, such as natural periods and vibration modes, can be obtained from this analysis. These will give engineers important information on the floating roof design.

Author(s):  
Shoichi Yoshida ◽  
Kazuyoshi Sekine ◽  
Katsuki Iwata

The floating roofs are widely used to prevent evaporation of content in large oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to the floating roofs due to liquid sloshing. The structural integrity of the floating roofs for the sloshing is urgent issue to establish in the petrochemical and oil refining industries. This paper presents the sloshing characteristics of the single deck floating roofs in cylindrical storage tanks. The hydrodynamic coupling of fluid and floating roof is taken into consideration in the axisymmetric finite element analysis. It is assumed that the fluid is incompressible and inviscid, and the floating roof is linear elastic while the sidewall and the bottom are rigid. The basic vibration characteristics, natural periods and vibration modes, of the floating roof due to the sloshing are investigated. These will give engineers important information on the floating roof design.


Author(s):  
Shoichi Yoshida ◽  
Kazuyoshi Sekine ◽  
Tomohiko Tsuchida ◽  
Katsuki Iwata

Floating roofs are widely used to prevent evaporation of contents of large cylindrical oil storage tanks. The 2003 Tokachi-Oki earthquake caused severe damage to floating roofs due to liquid sloshing. Seven single-deck floating roofs deformed to leak oil on them, and they lost buoyancy to sink. Two of them were the single-deck type with center pontoon in large diameter tanks. The present paper deals with an axisymmetric finite element analysis for the sloshing response of a floating roof with center pontoon. The hydrodynamic coupling of the fluid and the floating roof under seismic excitation is taken into consideration in the analysis. The fluid is assumed to be incompressible and inviscid, and the roof is assumed to be linear elastic. In addition, the sidewall and the bottom are assumed to be rigid. In the finite element analysis, the behavior of the fluid is formulated in terms of dynamic pressure using the Eulerian approach. The basic vibration characteristics of the single-deck floating roof with center pontoon, such as the natural periods and vibration modes, can be obtained from this analysis. These characteristics are shown comparing with those of the single-deck floating roof without center pontoon. The seismic response analysis for the input of an earthquake wave is also performed.


Author(s):  
Forhad Ahmad ◽  
M. M. Hossain ◽  
R. Seshadri

Storage tanks are widely used in the industry to store hydrocarbon products. Corrosion damage is considered to be a serious threat to the structural integrity of the industrial storage tanks if it occurs on the primary pressure containment boundary. Therefore, fitness-for-service (FFS) assessment of these structures is performed periodically in order to ensure the operational safety and structural integrity. In this paper, evaluation methods are proposed for FFS assessment of storage tanks undergoing corrosion damage. The proposed methods are shown to give reasonably accurate and conservative assessment of the remaining strength factor. The methods are demonstrated through an example and the results verified by inelastic finite element analysis.


2010 ◽  
Vol 132 (2) ◽  
Author(s):  
F. Ahmad ◽  
M. M. Hossain ◽  
R. Seshadri

Storage tanks are widely used in the industry to store hydrocarbon products. Corrosion damage is considered to be a serious threat to the structural integrity of the industrial storage tanks if it occurs on the primary pressure containment boundary. Therefore, fitness-for-service (FFS) assessment of these structures is performed periodically in order to ensure the operational safety and structural integrity. In this paper, evaluation methods are proposed for FFS assessment of storage tanks undergoing corrosion damage. The proposed methods are shown to give reasonably accurate and conservative assessment of the remaining strength factor. The methods are demonstrated through an example and the results are verified by inelastic finite element analysis.


1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier

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.


2021 ◽  
Vol 335 ◽  
pp. 03011
Author(s):  
Mohammed Shariff Mohamed Sulaiman ◽  
Seong Chun Koay ◽  
Ming Yeng Chan ◽  
Hui Leng Choo ◽  
Ming Meng Pang ◽  
...  

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.


2005 ◽  
Vol 127 (1) ◽  
pp. 34-37 ◽  
Author(s):  
Ravi Chandra Sikakollu ◽  
Lemmy Meekisho ◽  
Andres LaRosa

This paper deals with the design and analysis of a horizontal thermal actuator common in MEMS applications using Finite Element Analysis; with the objective of exploring means to improve its sensitivity. The influence of variables like voltage and the dimensions of the cold arm of the actuator unit were examined by comprehensive, coupled thermal-stress analyses. Simulation results from this study showed that the sensitivity of the actuator increases with the applied voltage as well as the width of the cold arm of the thermal actuator. An important observation made from this study is that the size and thermal boundary conditions at the fixed end of the actuator primarily control the stroke and the operating temperature of the actuator for a given potential difference between cold and hot arms. The coupled field analyses also provided a design tool for maximizing the service voltage and dimensional variables without compromising the thermal or structural integrity of the actuator.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Asif Israr

This paper presents design, modeling, and analysis of satellite model used for remote sensing. A detailed study is carried out for the design and modeling of the satellite structure focusing on the factors such as the selection of material, optimization of shape and geometry, and accommodation of different subsystems and payload. The center of mass is required to be kept within the range of (1-2) cm from its geometric center. Once the model is finalized it is required to be analyzed by the use ofAnsys, a tool for finite element analysis (FEA) under given loading and boundary conditions. Static, modal, and harmonic analyses inAnsysare performed at the time of ground testing and launching phase. The finite element analysis results are also validated and compared with the theoretical predictions. These analyses are quite helpful and suggest that the satellite structure does not fail and retains its structural integrity during launch environment.


Author(s):  
Muhammad Abid ◽  
Abdul W. Awan

A number of analytical and experimental studies have been conducted to study ‘strength’ and ‘sealing capability’ of bolted flange joint only under internal pressure loading. Due to the ignorance of the external i.e. axial loading, the optimized performance of the bolted flange joint can not be achieved. A very limited work is found in literature under combined internal pressure and axial loading. In addition, the present design codes do not address the effects of axial loading on the structural integrity and sealing ability of the flange joints. From previous studies, non-gasketed joint is claimed to have better performance as compared to conventional gasketed joint. To investigate non-gasketed joint’s performance i.e. joint strength and sealing capability under combined internal pressure and any applied external loading, an extensive 3D nonlinear finite element analysis is carried out and overall joint performance and behavior is discussed.


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