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.

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.

Elliptical Deformation of a Floating Roof Pontoon Due to Radial Second Mode of Sloshing (Effect of the Geometry of Pontoon Cross-Section on the Hoop Membrane Stress)

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
M. Utsumi ◽  
K. Ishida
Keyword(s):  
Cross Section ◽  
Plane Deformation ◽  
Previous Method ◽  
Improved Method ◽  
Membrane Stress ◽  
Oil Storage ◽  
Second Mode ◽  
Out Of Plane ◽  
Bending Stresses ◽  
Circumferential Wave

The radial second mode of sloshing in a circular cylindrical oil storage tank induces an out-of-plane deformation of the floating roof deck. The radial contraction of the deck due to this out-of-plane deformation contains modal components with circumferential wave numbers 0 and 2, thereby causing an elliptical deformation of the pontoon, which encloses the deck. In a previous paper, the stress caused by this elliptical deformation was analyzed by regarding the radial contraction of the deck as an enforced displacement of the whole pontoon. This paper presents an improved method for this stress analysis by considering the radial contraction of the deck as an enforced displacement of the joint between the deck and the pontoon. First, the effectiveness of the previous method in estimating the hoop membrane stress at the joint with the deck is confirmed by comparing the results obtained from the previous and improved method. Next, the improved method is used to predict also the other stress components in each portion of the pontoon. Numerical results reveal that the bending stresses are magnified locally near the joint with the deck and that the hoop membrane stress in the outer portion of the pontoon sensitively depends on the geometry of the cross-section of the pontoon. It is found that the hoop membrane stress near the joint between the outer rim and the top (or bottom) of the pontoon can be significantly reduced by increasing the slope of the top (or bottom) of the pontoon.

Vibration Analysis of a Floating Roof Subjected to Radial Second Mode of Sloshing

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
M. Utsumi ◽  
K. Ishida
Keyword(s):  
Storage Tank ◽  
Plane Deformation ◽  
Analysis Method ◽  
Numerical Result ◽  
Oil Storage ◽  
Second Mode ◽  
Oil Storage Tank ◽  
Out Of Plane ◽  
Cost Efficient ◽  
Good Agreement

In a previous paper, a cost-efficient modal analysis method for the vibration of a floating roof coupled with nonlinear sloshing in a circular cylindrical oil storage tank is presented. This method is extended to the case in which the out-of-plane deformation of the roof-deck caused by the radial second mode of sloshing induces an elliptical deformation of the pontoon around the deck. First, the radial contraction of the deck is calculated from the slope of the out-of-plane deformation of the deck, and the following two points are confirmed: (i) the circumferential variation in this radial contraction results in the elliptical deformation of the pontoon, and (ii) the present theoretical prediction for the radial contraction is in good agreement with a numerical result obtained by LS-DYNA. Based on these points, the stresses arising in the pontoon are calculated by considering the contraction of the deck as an enforced displacement of the pontoon. Numerical results show that (a) the elliptical deformation of the pontoon causes a large circumferential in-plane stress, (b) reduction achieved by the increase in the thickness of the deck is larger for the radial contraction of the deck and the stresses in the pontoon than for the out-of-plane deformation of the deck, and (c) the radial contraction of the deck for a fixed value of the out-of-plane deformation of the deck increases with the decrease in the radius of the deck.

scholarly journals In situ observations on deformation behavior and stretching-induced failure of fine pitch stretchable interconnect

2009 ◽  
Vol 24 (12) ◽  
pp. 3573-3582 ◽  
Author(s):  
Yung-Yu Hsu ◽  
Mario Gonzalez ◽  
Frederick Bossuyt ◽  
Fabrice Axisa ◽  
Jan Vanfleteren ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Plane Deformation ◽  
Plane Shear ◽  
Deformation And Failure ◽  
Fine Pitch ◽  
Wearable Systems ◽  
Out Of Plane ◽  
Failure Location ◽  
Stretchable Interconnect

Electronic devices capable of performing in extreme mechanical conditions such as stretching, bending, or twisting will improve biomedical and wearable systems. The required capabilities cannot be achieved with conventional building geometries, because of structural rigidity and lack of mechanical stretchability. In this article, a zigzag-patterned structure representing a stretchable interconnect is presented as a promising type of building block. In situ experimental observations on the deformed interconnect are correlated with numerical analysis, providing an understanding of the deformation and failure mechanisms. The experimental results demonstrate that the zigzag-patterned interconnect enables stretchability up to 60% without rupture. This stretchability is accommodated by in-plane rotation of arms and out-of-plane deformation of crests. Numerical analysis shows that the dominating failure cause is interfacial in-plane shear stress. The plastic strain concentration at the arms close to the crests, obtained by numerical simulation, agrees well with the failure location observed in the experiment.

scholarly journals Numerical analysis of out-of-plane deformation of shear wall

2019 ◽  
Vol 357 ◽  
pp. 012001
Author(s):  
B.N.A. Al-Gabri ◽  
A.B. Nabilah ◽  
F.N.A. Abdul Aziz ◽  
I.A. Karim
Keyword(s):  
Numerical Analysis ◽  
Plane Deformation ◽  
Shear Wall ◽  
Out Of Plane

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.

Out-of-plane loaded masonry walls retrofitted with oriented strand boards: Numerical analysis and influencing parameters

2021 ◽  
Vol 243 ◽  
pp. 112683
Author(s):  
Jamiu A. Dauda ◽  
Luis C. Silva ◽  
Paulo B. Lourenço ◽  
Ornella Iuorio
Keyword(s):  
Numerical Analysis ◽  
Masonry Walls ◽  
Out Of Plane ◽  
Influencing Parameters

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
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