Shear Design of Wide Beam Ribbed Slabs

2011 ◽  
Vol 72 (3) ◽  
Author(s):  
Teck Leong Lau
Keyword(s):  
Test Data ◽  
Design Method ◽  
Code Design ◽  
Wide Beam ◽  
Empirical Assumption ◽  
Shear Design ◽  
Basic Code ◽  
Shear Area ◽  
Good Agreement ◽  
Made In

A method for the shear design of wide beam ribbed slabs is proposed. The method modifies the current UK code design method for solid slabs by applying a shear area factor which reduces the area of the code critical shear perimeter to take account of the loss of shear area from that of a solid slab. The proposed method gives good agreement with test data for internal column situations, and underestimates the strength at edge columns. The conservativeness in relation to edge columns arises because of an empirical assumption made in the basic code method for solid slabs and is not due to the modification that it is proposed for wide beam ribbed slabs.

An Update on Improved Flange Design Methods

2007 ◽  
Author(s):  
Warren Brown
Keyword(s):  
Design Method ◽  
Design Methods ◽  
Project Development ◽  
Design Improvement ◽  
Panel Session ◽  
Improved Methods ◽  
Made In

This paper details further progress made in the PVRC project “Development of Improved Flange Design Method for the ASME VIII, Div.2 Rewrite Project” presented during the panel session on flange design at the 2006 PVP conference in Vancouver. The major areas of flange design improvement indicated by that project are examined and the suggested solutions for implementing the improved methods into the Code are discussed. Further analysis on aspects such as gasket creep and the use of leakage-based design has been conducted. Shortcomings in the proposed ASME flange design method (ASME BFJ) and current CEN flange design methods (EN-1591) are highlighted and methods for resolution of these issues are suggested.

scholarly journals A balanced-to-balanced directional coupler based on branch-slotline coupled structure

Frequenz ◽  
2020 ◽  
Vol 74 (11-12) ◽  
pp. 427-433
Author(s):  
Yaxin Liu ◽  
Feng Wei ◽  
Xiaowei Shi ◽  
Cao Zeng
Keyword(s):  
Directional Coupler ◽  
Return Loss ◽  
Design Method ◽  
Differential Mode ◽  
Arbitrary Power ◽  
Measurement Results ◽  
Transition Structures ◽  
Coupled Structures ◽  
Better Than ◽  
Good Agreement

AbstractIn this paper, a balanced-to-balanced (BTB) branch-slotline directional coupler (DC) is firstly presented, which can realize an arbitrary power division ratios (PDRs). The coupler is composed by microstrip-to-slotline (MS) transition structures and branch-slotline coupled structures. The single-ended to balanced-ended conversion is simplified and easy to implemented by the MS transition structures, which intrinsically leads to the differential-mode (DM) transmission and common-mode (CM) suppression. Moreover, the different PDRs which are controlled by the widths of branch-slotlines can be achieved. In order to verify the feasibility of the proposed design method, two prototype circuits of the proposed coupler with different PDRs are fabricated and measured. The return loss and the isolation of two designs are all better than 10 dB. Moreover, the CM suppressions are greater than 35 dB. A good agreement between the simulation and measurement results is observed.

scholarly journals An approach to the modeling of a virtual thermal manikin

2014 ◽  
Vol 18 (4) ◽  
pp. 1413-1423 ◽  
Author(s):  
Dragan Ruzic ◽  
Sinisa Bikic
Keyword(s):  
Turbulence Models ◽  
Thermal Conditions ◽  
Heat Fluxes ◽  
Thermal Manikin ◽  
Flow Conditions ◽  
Body Segments ◽  
Nominal Size ◽  
Natural Flow ◽  
Good Agreement ◽  
Made In

The aim of the research described in this paper, is to make a virtual thermal manikin that would be simple, but also robust and reliable. The virtual thermal manikin was made in order to investigate thermal conditions inside vehicle cabins. The main parameters of the presented numerical model that were investigated in this paper are mesh characteristics and turbulence models. Heat fluxes on the manikin's body segments obtained from the simulations were compared with published results, from three different experiments done on physical thermal manikins. The presented virtual thermal manikin, meshed with surface elements of 0.035 m in nominal size (around 13,600 surface elements) and in conjunction with the two-layer RANS Realizable k-? turbulence model, had generally good agreement with experimental data in both forced and natural flow conditions.

scholarly journals Post-liquefaction reconsolidation of sand

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150745 ◽  
Author(s):  
O. Adamidis ◽  
G. S. P. Madabhushi
Keyword(s):  
Void Ratio ◽  
One Dimensional ◽  
Geotechnical Centrifuge ◽  
Significant Damage ◽  
Pore Water Pressures ◽  
The One ◽  
Crucial Parameter ◽  
Excess Pore ◽  
Good Agreement ◽  
Made In

Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

Einheitliches Querkraftmodell für Stahl- und Spannbetonbrücken – erweiterte Grundlagen/Uniform Shear Design Method for Existing Reinforced and Prestressed Concrete Bridges – Extended Background

Bauingenieur ◽  
2016 ◽  
Vol 91 (12) ◽  
pp. 487-495
Author(s):  
Martin Herbrand ◽  
Martin Classen ◽  
Alexander Stark ◽  
Dominik Kueres
Keyword(s):  
Prestressed Concrete ◽  
Design Method ◽  
Concrete Bridges ◽  
Prestressed Concrete Bridges ◽  
Shear Design ◽  
Uniform Shear

Während das Biegetragverhalten von Stahl- und Spannbetonbauteilen als gelöst angesehen wird, ist das Querkrafttragverhalten schubschlanker Bauteile nicht abschließend geklärt. Vor allem für die Beurteilung von Bestandsbauwerken sind aber Querkraftmodelle notwendig, die möglichst einfach anwendbar sind und dennoch ausreichend genaue und damit wirtschaftliche Vorhersagen der Tragfähigkeit erlauben. Ein einheitliches Querkraftmodell mit Betontraganteil für Stahl- und Spannbetonbauteile ermöglicht bei der Bemessung einen stetigen Übergang zwischen Bauteilen ohne und mit Querkraftbewehrung, wenn deren Betontraganteile für asw = 0 identisch sind. Der Vergleich mit den ACI-DAfStb-Querkraftdatenbanken belegt, dass ein solches Modell für Bauteile mit Querkraftbewehrung zu deutlich geringeren Streuungen und gleichzeitig einem höheren Sicherheitsniveau im Vergleich zum aktuellen EC2 führt. Insbesondere für Bauteile mit geringen Querkraftbewehrungsgraden ergeben sich hierdurch höhere rechnerische Tragfähigkeiten, was zum Beispiel für die Nachrechnung von Bestandsbauwerken wie Brücken von Vorteil ist. In diesem Beitrag werden die Hintergründe für einen konsistenten Übergang von einen Fachwerkmodell mit Betontraganteil zu einem Fachwerkmodell mit variabler Druckstrebenneigung erläutert.

An analytical model of an I-cored coil located above a conductive material with a hole

2018 ◽  
Vol 82 (2) ◽  
pp. 21001
Author(s):  
Grzegorz Tytko ◽  
Leszek Dziczkowski
Keyword(s):  
Test Object ◽  
Middle Layer ◽  
Axially Symmetric ◽  
The Finite Element Method ◽  
Cylindrical Coordinate ◽  
Air Space ◽  
Through Hole ◽  
Tree Method ◽  
Good Agreement ◽  
Made In

The paper examines the problem of an axially symmetric I-cored coil located above a three-layered plate with a hole in the middle layer. A cylindrical coordinate system was applied, wherein the solution domain was truncated in the radial direction. The employment of the truncated region eigenfunction expansion (TREE) method resulted in deriving the final formulas for the change of the coil impedance with regard to the air space, and also pertaining to the test object without a flaw. Formulas for various configurations of the test object, among others for a surface hole, a subsurface hole and a through hole, have been presented. For the purpose of defectoscopy, the influence of the hole in the plate on the impedance components was investigated. The calculations were made in Matlab for frequencies from 100 Hz to 50 kHz. The obtained results were verified using the finite element method (FEM) in Comsol Multiphysics package. A very good agreement was observed in the case of both the resistance and reactance.

scholarly journals In-Depth Verification of a Numerical Model for an Axisymmetric RC Dome

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2152
Author(s):  
Przemysław Czumaj ◽  
Sławomir Dudziak ◽  
Zbigniew Kacprzyk
Keyword(s):  
Three Dimensional ◽  
Spatial Models ◽  
Detailed Comparison ◽  
The Finite Element Method ◽  
Robot System ◽  
Engineering Structures ◽  
Computational Analyses ◽  
Computational Systems ◽  
Good Agreement ◽  
Made In

The designers of civil engineering structures often have to face the problem of the reliability of complex computational analyses performed most often with the Finite Element Method (FEM). Any assessment of reliability of such analyses is difficult and can only be approximate. The present paper puts forward a new method of verification and validation of the structural analyses upon an illustrative example of a dome strengthened by circumferential ribs along the upper and lower edges. Four computational systems were used, namely Abaqus, Autodesk Robot, Dlubal RFEM, and FEAS. Different models were also analyzed—two-dimensional (2D) and three-dimensional (3D) ones using continuum, bar, and shell finite elements. The results of the static (with two kinds of load—self-weight and load distributed along the upper ring) and modal analyses are presented. A detailed comparison between the systems’ and models’ predictions was made. In general, the spatial models predicted a less stiff behavior of the analyzed dome than the planar models. The good agreement between different models and systems was obtained for the first natural frequency with axisymmetric eigenmodes (except from the Autodesk Robot system). The presented approach to the verification of complex shell–bar models can be effectively applied by structural designers.

scholarly journals A numerical study of cell merger over Cuba – Part I: implementation of the ARPS/MM5 models

2006 ◽  
Vol 24 (11) ◽  
pp. 2781-2792 ◽  
Author(s):  
D. Pozo ◽  
I. Borrajero ◽  
J. C. Marín ◽  
G. B. Raga
Keyword(s):  
Mesoscale Model ◽  
Numerical Study ◽  
Initial Boundary ◽  
Radar Data ◽  
Horizontal Resolution ◽  
Convective Systems ◽  
Maximum Reflectivity ◽  
Radar Echoes ◽  
Good Agreement ◽  
Made In

Abstract. On 21 July 2001 a number of severe storms developed over the region of Camaguey, Cuba, which were observed by radar. A numerical simulation was performed in order to realistically reproduce the development of the storms observed that day. The mesoscale model MM5 was used to determine the initial, boundary and update conditions for the storm-scale simulation with the model ARPS. Changes to the source code of ARPS were made in order to assimilate the output from the MM5 as input data and a new land-use file with a 1-km horizontal resolution for the Cuban territory was created. A case representing the merger between cells at different stages of development was correctly reproduced by the simulation and is in good agreement with radar observations. The state of development of each cell, the time when the merger occurred, starting from the formation of clouds, the propagation motion of the cells and the increase in precipitation, due to the growth of the area after the merger, were correctly reproduced. Simulated clouds matched the main characteristics of the observed radar echoes, though in some cases, reflectivity tops and horizontal areas were overestimated. Maximum reflectivity values and the heights where these maximum values were located were in good agreement with radar data, particularly when the model reflectivity was calculated without including the snow. The MM5/ARPS configuration introduced in this study, improved sensibly the ability to simulate convective systems, thereby enhancing the local forecasting of convection in the region.

scholarly journals The House Reformed: A Reaction to Suburban Monotony

2021 ◽  
Author(s):  
◽  
Florence Mangan
Keyword(s):  
Design Method ◽  
Well Being ◽  
Mass Scale ◽  
Life Styles ◽  
Hands On ◽  
Final Design ◽  
Manual Methods ◽  
The Aesthetic ◽  
House Design ◽  
Made In

<p>Joyless rows of monotonous houses are be- ginning to define the suburban typology of tomorrow. Quality and innovation is being compromised for speed and quantity and there is a distinct lack of consideration for the home’s potential to enrich and influence the life-styles and well-being of its occupants.  This thesis is a reaction to the researcher’s dis- satisfaction with New Zealand’s suburban typology and seeks to identify and demonstrate an alternative design approach. The research- er considers that a house should enable its occupants to flourish by instigating moments of joy and surprise whilst maximising economy of space.  The thesis uses an investigative research method of five different design tests. Each test reveals strategies to aid the approach of designing the suburban typology, focusing on maximising joy, surprise and economy of space.  Both digital and manual methods are used, revealing their respective strengths and flaws. The Digital method used in the Data House and Rigid x Fluid house tests lacked the ability to apply tangible aesthetic qualities to a de- sign. The manual hands on method of used in the Patchwork House and House Reformed tests was hugely beneficial for the aesthetic qualities of design, however it lacked the rigor and capacity to apply individuality on a mass scale.  Discoveries made in the thesis investigations are collated in a final design outcome, the House Reformed. This house design demonstrates a compilation of the successful strategies identified in the research and reveals the benefits of approaching home design with qualities of joy, surprise and economy of space. The most successful strategies used to achieve these aims were establishing a great- er connection with the outdoors, providing flexible spaces through the use of innovative partitions and furniture and injecting unexpected aesthetic moments through the use of interesting texture and colour.  Overall the research reveals a successful de- sign outcome and provides interesting in- sights into design method. It explores worth- while questions and issues related to the lived domestic experience such as the lack of joy, surprise and economy of space in suburban housing and demonstrates the importance of designing with such qualities.</p>

Effect of Shallow Water on a Mathematical Hull at High Subcritical and Supercritical Speeds

1986 ◽  
Vol 30 (02) ◽  
pp. 85-93
Author(s):  
A. Millward ◽  
M. G. Bevan
Keyword(s):  
Shallow Water ◽  
Wave Theory ◽  
Hull Form ◽  
Towing Tank ◽  
Resistance Peak ◽  
Good Agreement ◽  
Made In

Experiments have been made in a towing tank to measure the resistance of a mathematical hull form in deepwater and in shallow water at high subcritical and supercritical speeds. The data have been compared with calculations using linearized wave theory for the same hull shape. The results have shown fairly good agreement, with the greatest differences occurring near the subcritical resistance peak.

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