scholarly journals Numerical Model for Cyclic Compressive Behavior of Concrete Confined by Steel Plates Using External Pressure

2013 ◽  
Vol 13 (1) ◽  
pp. 57-61
Author(s):  
Eunsoo Choi ◽  
Segeun Song
Keyword(s):  
Numerical Model ◽  
External Pressure ◽  
Steel Plates ◽  
Compressive Behavior

An Improved Design of Microchannel Fuel Processors

2005 ◽  
Author(s):  
Hye-Mi Jung ◽  
Sung-Dae Yim ◽  
Sukkee Um ◽  
Young-Gi Yoon ◽  
Gu-Gon Park ◽  
...  
Keyword(s):  
Numerical Model ◽  
Steam Reforming ◽  
Kinetic Equations ◽  
Methanol Conversion ◽  
Steel Plates ◽  
Catalyst Loading ◽  
Contact Method ◽  
Micro Channel ◽  
Catalytic Combustor ◽  
Improved Design

This paper focuses on a new systematic configuration of micro-channel fuel processors, particularly designed for portable applications. An alternative integration method of the micro-channel fuel processors is attempted to overcome the serious thermal unbalance and to minimize the system volume by introducing the direct contact method of the sub-components. An integrated micro-channel methanol processor was developed by assembling unit reactors, which were fabricated by stacking and bounding micro-channel patterned stainless steel plates, including fuel vaporizer, catalytic combustor and steam reformer. Commercially available Cu/ZnO/Al2O3 catalyst (ICI Synetix 33-5) was coated inside micro-channel of the unit reactor for steam reforming. The steam reforming reaction was conducted in the temperature range of 200°C to 260°C in the basis of reformer side end-plate and the temperature was controlled by varying methanol feeding into the combustor. More than 99% of methanol was converted at 240°C of reformer side temperature. A mechanism-based numerical model aimed at enhancing physical understanding and optimizing designs has been developed for improved micro-channel fuel processors. A two-dimensional numerical model in the reformer section created to model the phenomena of species transport and reaction occurring at the catalyst surface. The mass, momentum, and species equations were employed with kinetic equations that describe the chemical reaction characteristics to solve flow-field, methanol conversion rate, and species concentration variations along the micro-channel. This mechanism-based model was validated against the experimental data from the literature and then applied to various layouts of the micro-channel fuel processors targeted for the optimal catalyst loading and fuel reforming purpose. The computer-aided models developed in this study can be greatly utilized for the design of advanced fast-paced micro-channel fuel processors research.

scholarly journals EXPERIMENTAL, NUMERICAL AND ANALYTICAL INVESTIGATIONS OF WIND-INDUCED NET PRESSURES FOR INDUSTRIAL BUILDINGS WITH ENVELOPE POROSITIES

2016 ◽  
Vol 7 ◽  
pp. 58
Author(s):  
Vanessa Saubke ◽  
Rüdiger Höffer
Keyword(s):  
Spatial Distribution ◽  
Numerical Model ◽  
Wind Tunnel ◽  
External Pressure ◽  
Navier Stokes ◽  
Industrial Building ◽  
Wind Tunnel Experiments ◽  
Industrial Buildings ◽  
External Pressures

The magnitude and the spatial distribution of wind-induced net pressures (external and internal) on buildings are frequently discussed among research communities and construction industries. This paper deals with this topic based on a case study about an industrial building in Denmark, which was damaged due to the wind impact during a storm when a large part of the roof covering was blown off. In order to detect the reason for the damage the wind-induced loads were studied by i) wind tunnel experiments on the external pressures due to different wind directions, ii) analytical investigations of internal pressure due to envelope porosities and planned openings and iii) numerical analyses for the internal and the external pressure. The Reynolds averaged Navier-Stokes (RANS) method is employed to build a numerical model. The experimental, analytical and numerical results are compared with the indicated characteristic loads from the Eurocode.

Assessment of Design Collapse Equations for OCTG Pipes Under Combined Loads

2021 ◽  
Author(s):  
Eduardo Felipe Pereira da Silva ◽  
Theodoro Antoun Netto
Keyword(s):  
Numerical Model ◽  
Work Group ◽  
Experimental Tests ◽  
External Pressure ◽  
Combined Loading ◽  
Current Standard ◽  
Combined Loads ◽  
Axial Tension ◽  
Rating Method ◽  
Different Diameters

Abstract The objective of this paper is to evaluate the design collapse equations presented in chapter 8 and Annex F of the current standard ISO TR 10400 for casings under external pressure and axial tension. A nonlinear numerical model has been developed to analyze the performance of these equations to predict casing collapse under combined loads. Experimental tests have been performed with different diameters, d/h ratio and steel grade to calibrate the numerical model. The KT model has been assessed previously against different models by API Work Group and it has shown to be reliable to be used as design equations. However, the API Work Group included the KT model in the appendix F of the code as informative. The work done in this paper has confirmed the better performance of KT model for most of the cases analyzed. For combined loading, the API collapse equation results in a simple strength de-rating method, whilst the KT model has achieved similar behavior for low values of axial tension when comparing the experimental results. The axial tension for the casings into the well is likely to be lower than 40% of yield strength. Therefore, the KT model has shown to be more convenient to well design than API equations.

scholarly journals Numerical and Experimental Evaluation and Heat Transfer Characteristics of a Soft Magnetic Transformer Built from Laminated Steel Plates

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7939
Author(s):  
Eduardo Cano-Pleite ◽  
Andrés Barrado ◽  
Néstor Garcia-Hernando ◽  
Emilio Olías ◽  
Antonio Soria-Verdugo
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Numerical Models ◽  
Subsequent Development ◽  
Steel Plates ◽  
Maximum Temperature ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Anisotropic Thermal Conductivity

The present work evaluates, both experimentally and numerically, the heat transfer characteristics of a 5 kW three-phase transformer built from laminated steel sheets. The transformer is operated at different powers, and its temperature distribution is monitored using 108 thermocouples. The experimental measurements are used firstly to determine the heat dissipated at the core and the windings of the transformer. This information is used as an input for a finite element numerical model, which evaluates the heat transfer characteristics of the transformer. The model proposed in this work simply solves the diffusion equation inside the transformer, accounting for the anisotropic thermal conductivity of the different components of the transformer, together with well-known correlations at its boundaries. The results reveal that the proposed numerical model can correctly reproduce the maximum temperature, the temperature distribution, and the time-evolution of the temperature at specific points of the transformer measured during the experimental campaign. These results are of great use for the subsequent development of transformers of the same type in lab-scale or industrial-scale size and reveal the applicability of simplified numerical models to accurately predict the heat transfer characteristics of this kind of transformers.

The Effect of the Reeling Laying Method on the Collapse Pressure of Steel Pipes for Deepwater

2004 ◽  
Author(s):  
Ilson P. Pasqualino ◽  
Silvia L. Silva ◽  
Segen F. Estefen
Keyword(s):  
Numerical Model ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Element Model ◽  
External Pressure ◽  
Test Facility ◽  
Collapse Pressure ◽  
Steel Pipes ◽  
Custom Made ◽  
Nonlinear Finite Element Model

This work deals with a numerical and experimental investigation on the effect of the reeling installation process on the collapse pressure of API X steel pipes. A three-dimensional nonlinear finite element model was first developed to simulate the bending and straightening process as it occurs during installation. The model is then used to determine the collapse pressures of both intact and plastically strained pipes. In addition, experimental tests on full-scale models were carried out in order to calibrate the numerical model. Pipe specimens are bent on a rigid circular die and then straightened with the aid of a custom-made test facility. Subsequently, the specimens are tested quasi-statically under external pressure until collapse in a pressure vessel. Unreeled specimens were also tested to complete the database for calibrating the numerical model. The numerical model is finally used to generate collapse envelopes of reeled and unreeled pipes with different geometry and material.

Numerical Model of Stainless Steel Plates with Staggered Bolts Subjected to Tension

2010 ◽  
Author(s):  
Silva A. T. Da ◽  
Santos J. De J. Dos ◽  
Lima L. R. O. De ◽  
Vellasco P. C. G. Da S. ◽  
Silva J. G. S. Da ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Numerical Model ◽  
Steel Plates

scholarly journals Numerical Modeling and Mechanical Analysis of Flexible Risers

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
J. Y. Li ◽  
Z. X. Qiu ◽  
J. S. Ju
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Finite Element Model ◽  
Time Integration ◽  
Element Model ◽  
Mechanical Analysis ◽  
External Pressure ◽  
Integration Scheme ◽  
Fem Model ◽  
Flexible Risers

ABAQUS is used to create a detailed finite element model for a 10-layer unbonded flexible riser to simulate the riser’s mechanical behavior under three load conditions: tension force and internal and external pressure. It presents a technique to create detailed finite element model and to analyze flexible risers. In FEM model, all layers are modeled separately with contact interfaces; interaction between steel trips in certain layers has been considered as well. FEM model considering contact interaction, geometric nonlinearity, and friction has been employed to accurately simulate the structural behavior of riser. The model includes the main features of the riser geometry with very little simplifying assumptions. The model was solved using a fully explicit time-integration scheme implemented in a parallel environment on an eight-processor cluster and 24 G memory computer. There is a very good agreement obtained from numerical and analytical comparisons, which validates the use of numerical model here. The results from the numerical simulation show that the numerical model takes into account various details of the riser. It has been shown that the detailed finite element model can be used to predict riser’s mechanics behavior under various load cases and bound conditions.

scholarly journals Numerical Study on the Local Buckling Behaviour of Bolted Steel Plates in Steel Jacketing

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Xiao-liang Xu ◽  
Zhou-dao Lu ◽  
Ling-zhi Li ◽  
Chang-jiu Jiang
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Numerical Model ◽  
Parametric Study ◽  
Numerical Study ◽  
Local Buckling ◽  
Initial Imperfection ◽  
Field Capacity ◽  
Steel Plates ◽  
Previous Experimental Study

A numerical simulation was conducted to investigate the local buckling behaviour of the bolted steel plates in steel jacketing technique. The numerical model was firstly validated by the results of a previous experimental study. Then a parametric study was conducted to investigate the influence of different restraint measures on the local buckling behaviour and the sensitivity of the buckling behaviour to the initial imperfection. Fitted formulae were developed to calculate the structural field capacity of the bolted steel plates, and recommended values of stiffener size were also provided to facilitate the strengthening design of steel jacketing.

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