New Design Method to Evaluate the Seismic Stress of Single Deck Floating Roof for Storage Tanks

2015 ◽  
Vol 31 (1) ◽  
pp. 421-439 ◽  
Author(s):  
Mohammad Ali Goudarzi
Keyword(s):  
Design Method ◽  
Plane Deformation ◽  
Design Procedure ◽  
Nonlinear Behavior ◽  
Primary Source ◽  
Nonlinear Effects ◽  
Storage Tanks ◽  
Deck Plate ◽  
Out Of Plane ◽  
Seismic Stress

Liquid sloshing causes severe damage to the floating roofs of storage tanks. Liquid–roof interaction imposes a complicated distribution of out-of-plane deformation in a single deck floating roof (SDFR), which is the primary source of high seismic stress. This paper proposes a new seismic design procedure for evaluating the seismic stress of an SDFR. This method revises the relationship between vertical deformation of the deck plate and the radial shrinkage of the pontoon, and estimates the nonlinear behavior of the free surface. Moreover, the attenuation of the sloshing wave height attributable to the presence of an SDFR is analytically evaluated. A design flowchart according to the new method is suggested. This method emphasizes the nonlinear effects of large amplitude wave for smaller capacity tanks, and the seismic stress caused by the second sloshing mode for broad tanks.

Seismic Behavior of a Single Deck Floating Roof Due to Second Sloshing Mode

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Mohammad Ali Goudarzi
Keyword(s):  
Numerical Analysis ◽  
Seismic Behavior ◽  
Plane Deformation ◽  
Vertical Deformation ◽  
Radial Shrinkage ◽  
Deck Plate ◽  
Second Mode ◽  
Out Of Plane ◽  
Sloshing Mode ◽  
Seismic Stress

Second mode sloshing motion induces the vertical out-of-plane deformation of deck plate in single deck floating roof (FR) cylindrical storage tanks. This vertical deformation tends to shrink the deck plate in horizontal direction, causing elliptical deformation of pontoon. In order to evaluate seismic stress caused by the second sloshing mode, the relation between out-of-plane vertical deformation of deck plate and the radial shrinkage of pontoon is required. In this study, a simple analytical approach is proposed for calculating the shrinkage of the pontoon. The numerical analysis is also performed for five tanks with various dimensions to assess the effectiveness of introduced new method. The accuracy of proposed formulation is confirmed by comparing its results with the results of both numerical analysis and available experimental measurements. Despite existing empirical formula, geometric characteristics of considered tanks are involved in proposed formulation and it is shown that final relationship could be utilized for various ranges of tank dimensions without scaling or unit limitation. It is also found from the results of numerical analysis that the dynamic characteristics of sloshing modes are not considerably affected by the presence of floating roof.

Seismic Design of a Double Deck Floating Roof Type Used for Liquid Storage Tanks

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Mohammad Ali Goudarzi
Keyword(s):  
Seismic Design ◽  
Design Procedure ◽  
Hydrodynamic Pressure ◽  
Nonlinear Effects ◽  
Vertical Displacement ◽  
Bottom Plate ◽  
Liquid Storage ◽  
Geometric Nonlinear ◽  
General Displacement ◽  
Seismic Stress

Sloshing response of a cylindrical liquid storage tank with the double deck type floating roof (DDFR) subjected to seismic excitation is considered in this paper. The aim of the paper is to clarify the significant parameters that should be considered in the seismic design of a DDFR and proposing a practical seismic design procedure for evaluating the dynamic stresses inside a DDFR. A numerical method including fluid–structure interaction and the geometry details of a DDFR tank are established. The geometric nonlinear effects on the seismic behavior of the DDFR as well as the accuracy of common analytical solution suggested in the literature are examined by the numerical model. The numerical results show that the geometric nonlinear effects can considerably reduce the seismic stress in DDFR, but have no significant effect on the liquid hydrodynamic pressure exerted on the DDFR and the roof's vertical displacement. It is also revealed that not only the general displacement of DDFR but also the local effects of liquid hydrodynamic pressure on the bottom plate should be considered for seismic design of a DDFR. Finally, a design procedure for the evaluation of dynamic stress in the DDFR due to the seismic loads is proposed and discussed.

Seismic Design of Floating Roof of Oil Storage Tanks Under Liquid Sloshing

2006 ◽  
Author(s):  
Yoshihiko Yamauchi ◽  
Asamichi Kamei ◽  
Sinsaku Zama ◽  
Yoshinori Uchida
Keyword(s):  
Wave Height ◽  
Seismic Design ◽  
Response Spectrum ◽  
Nonlinear Behavior ◽  
Liquid Sloshing ◽  
Storage Tanks ◽  
Natural Period ◽  
Oil Storage ◽  
Deck Plate ◽  
Sloshing Mode

The 2003 Tokachi-oki earthquake caused the severe damage to oil storage tanks by liquid sloshing. Especially at Tomakomai in Hokkaido, the ground motions at the periods of 3 to 8 sec predominated, which were harmonized with the natural period of liquid sloshing of oil storage tanks, then seven single-deck-type floating roofs were damaged and sank. For the 30,000kl FRT(φ 42.7m), one of those tanks, with about 7 see of fundamental sloshing period, maximum sloshing wave height was estimated 3m and over. On the other hand, for the 100,000kl FRT(φ 78.2m) with about 12 sec of fundamental sloshing period, maximum sloshing wave height was estimated about 1.5m and the excitation of 2nd sloshing mode was considered to be strongly excited. Considering both of nonlinear behavior of a large amplitude wave of 1st sloshing mode and nonlinear effects of large deflection of a deck plate at 2nd sloshing mode, we established the simplified method of seismic design of single-deck-type floating roofs using modified velocity response spectrum. This spectrum was based on many studies, investigated by Zama [1] and others, of the prediction of long-period strong ground motion and of liquid sloshing of oil tanks in Japan.

scholarly journals Characterization and ballistic performance of thin pre-damaged resin-starved aramid-fiber composite panels

2021 ◽  
pp. 004051752110134
Author(s):  
Cerise A Edwards ◽  
Stephen L Ogin ◽  
David A Jesson ◽  
Matthew Oldfield ◽  
Rebecca L Livesey ◽  
...  
Keyword(s):  
Fiber Composite ◽  
Plane Deformation ◽  
Ballistic Impact ◽  
Image Correlation ◽  
Composite Panel ◽  
Composite Panels ◽  
Micro Computed Tomography ◽  
Ballistic Performance ◽  
Low Level ◽  
Out Of Plane

Military personnel use protective armor systems that are frequently exposed to low-level damage, such as non-ballistic impact, wear-and-tear from everyday use, and damage during storage of equipment. The extent to which such low-level pre-damage could affect the performance of an armor system is unknown. In this work, low-level pre-damage has been introduced into a Kevlar/phenolic resin-starved composite panel using tensile loading. The tensile stress–strain behavior of this eight-layer material has been investigated and has been found to have two distinct regions; these have been understood in terms of the microstructure and damage within the composite panels investigated using micro-computed tomography and digital image correlation. Ballistic testing carried out on pristine (control) and pre-damaged panels did not indicate any difference in the V50 ballistic performance. However, an indication of a difference in response to ballistic impact was observed; the area of maximal local out-of-plane deformation for the pre-damaged panels was found to be twice that of the control panels, and the global out-of-plane deformation across the panel was also larger.

scholarly journals In-Process Measurement of Three-Dimensional Deformations Based on Speckle Photography

2021 ◽  
Vol 11 (11) ◽  
pp. 4981
Author(s):  
Andreas Tausendfreund ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
Evaluation Method ◽  
Process Analysis ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Machining Process ◽  
Image Correlation ◽  
Speckle Photography ◽  
Process Measurement ◽  
Out Of Plane ◽  
Plane Deformations

In the concept of the process signature, the relationship between a material load and the modification remaining in the workpiece is used to better understand and optimize manufacturing processes. The basic prerequisite for this is to be able to measure the loads occurring during the machining process in the form of mechanical deformations. Speckle photography is suitable for this in-process measurement task and is already used in a variety of ways for in-plane deformation measurements. The shortcoming of this fast and robust measurement technique based on image correlation techniques is that out-of-plane deformations in the direction of the measurement system cannot be detected and increases the measurement error of in-plane deformations. In this paper, we investigate a method that infers local out-of-plane motions of the workpiece surface from the decorrelation of speckle patterns and is thus able to reconstruct three-dimensional deformation fields. The implementation of the evaluation method enables a fast reconstruction of 3D deformation fields, so that the in-process capability remains given. First measurements in a deep rolling process show that dynamic deformations underneath the die can be captured and demonstrate the suitability of the speckle method for manufacturing process analysis.

Inverse algorithm for out-of-plane deformation in shearography

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Shuangle Wu ◽  
Fangyuan Sun ◽  
Haotian Xie ◽  
Qihan Zhao ◽  
Peizheng Yan ◽  
...  
Keyword(s):  
Plane Deformation ◽  
Inverse Algorithm ◽  
Out Of Plane

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

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