scholarly journals A Note on the Structural Assessment of Perforated Panels used in Façade

2021 ◽  
pp. 123-128
Author(s):  
Muhammad Tayyab Naqash
Keyword(s):  
Numerical Model ◽  
Middle East ◽  
Wind Load ◽  
Design Tools ◽  
Structural Assessment ◽  
Shell Elements ◽  
Acceptance Criterion ◽  
Cladding Panels ◽  
Induced Stresses ◽  
Software Codes

Different materials such as glass and composite cladding panels are common in the façade industry due to their architectural appearance. The direct sun rays enter the building and might produce discomfort to the occupants, especially in office and institutional buildings. Nowadays, perforated panels are widely used in facades and becoming more popular in the middle east. These panels are a formal exploration inspired by the Islamic patterns used in traditional Mashrabiya. This paper provides an overview of the application of Mashrabiya "perforated panels" and present structural assessment using software codes such as Robot and SAP2000 for vertical and horizontal installed cases. These panels are fabricated in different sizes with different thicknesses depends on their applications and uses. In this paper, rectangular, square fixed at the roof and vertically fixed panels are assessed. These are usually supported by steel or aluminium tubes designed for a wind load specified by project specifications. The cases presented here for the perforated panels arechecked for the induced stresses and deflections obtained from the numerical model using shell elements. The adopted framing systems and fixing detailing has been found satisfactory according to different acceptance criterion. The paper gives helpful design tools for the façade engineers.

scholarly journals Optimizing Surface Micro Grooving to Reduce the Checking and Cupping of Douglas Fir, Western Hemlock and White Spruce Decking Exposed to Natural Weathering

2018 ◽  
Vol 2 (4) ◽  
pp. 67 ◽  
Author(s):  
Sina Heshmati ◽  
Mohammad Mazloomi ◽  
Philip Evans
Keyword(s):  
Numerical Model ◽  
White Spruce ◽  
Groove Depth ◽  
Douglas Fir ◽  
The Other ◽  
Western Hemlock ◽  
Natural Weathering ◽  
Micro Grooving ◽  
Induced Stresses

Machining grooves into the surface of pine and fir (Abies spp.) deckboards reduces undesirable checking that develops when “profiled” boards are exposed to the weather. We aim to develop improved profiles for Douglas fir, western hemlock and white spruce decking to reduce their susceptibility to checking, and understand how profile geometry influences the stresses that cause checking. We varied the width and depth of grooves in profiled deckboards, exposed deckboards to the weather, and measured checking and cupping of boards. A numerical model examined the effect of groove depth on the moisture-induced stresses in profiled spruce boards. Profiling significantly reduced checking, but increased cupping of deckboards made from all three species. Western hemlock checked more than the other two species. Profiles with narrow grooves (rib profiles) were better at restricting checking than profiles with wider grooves. A rib profile with deeper grooves developed smaller stresses than a rib profile with shallower grooves, and boards with the former profile checked less than boards with shallower grooves. We conclude that checking of profiled Douglas fir, western hemlock and white spruce decking is significantly reduced by changing profile geometry, and our results suggest the best profiles to reduce checking of all three species.

Design Tools for the Performance Improvement of a 76 MW Francis Turbine Runner

2009 ◽  
Author(s):  
Jose´ Manuel Franco-Nava ◽  
Oscar Dorantes-Go´mez ◽  
Erik Rosado-Tamariz ◽  
Jose´ Manuel Ferna´ndez-Da´vila ◽  
Reynaldo Rangel-Espinosa
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Finite Element ◽  
Performance Improvement ◽  
Three Dimensional ◽  
Francis Turbine ◽  
Design Tools ◽  
Turbine Runner ◽  
Induced Stresses ◽  
Fluid Behaviour

Application of two mayor design tools, Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD), for the performance improvement of a 76 MW Francis turbine runner is presented. In order to improve the performance of the runner, not only a CFD based optimization for the runner but also its structural integrity evaluation was carried out. In this paper, a number of analyses included within the design tools-based runner optimization process are presented. Initially, a reference condition for the fluid behaviour through turbine components was carried out by means of the computation of fluid conditions through the spiral case and stays vanes, followed by CFD-based fluid behaviour for the wicket so as to include the flow effects induced by these components in the final CFD analysis for the runner. All CFD computations were generated within the three dimensional Navier-Stoke commercial turbomachinery oriented CFD code FINE™/Turbo from NUMECA. The whole hydraulic turbine performance was then compared against actual data from a medium-head Francis type hydro turbine (76 MW). Then, CFD-based flow induced stresses in the turbine runner were computed by using a three dimensional finite element model built within the FEA commercial code ANSYS. Appropriate boundary conditions were set in order to obtain the results due to the different type loads (pressure and centrifugal force). The FEM model was able to capture the pressure gradients on the blade surfaces obtained from the CFD results. Improvement of efficiency and power for the runner was computed by using a parametric model built within 3D CFD code integrated environment FINETM/Design3D from NUMECA which combines genetic algorithms and a trained artificial neural network. During the optimization process the artificial neural network is trained with a database of geometries and their respective CFD computations in order to determine the optimum geometry for a given objective function. The optimisation process and the trend curve of the optimization or design cycle that included 29 parameters (corresponding to the control points of runner blade primary sections) which could vary during the process is presented. Finally, the flow induced stresses of the optimized Francis turbine runner was computed so as to evaluate the final blade geometry modifications related to the efficiency and power improvement.

scholarly journals THE WOOD‐FRAMED WITH SHEATHING BUILDINGS ‐ ALTERNATIVE FOR HOUSING CONSTRUCTION

2006 ◽  
Vol 12 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Mikołaj Malesza ◽  
Czesław Miedziałowski
Keyword(s):  
Numerical Model ◽  
Composite Structure ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Beam Element ◽  
Housing Construction ◽  
Residential Housing ◽  
Shell Elements ◽  
Linear Behaviour ◽  
Floor Diaphragms

Numerical model of the wood‐framed with sheathing structure and selected results of experimental tests are presented in the paper. Wall and floor diaphragms as the three‐dimensional composite structure are modeled applying plane shell elements representing framing and sheathing and beam element describing the fasteners. Experimental tests were conducted on typically disposed the wood‐framed wall and floor diaphragms in residential housing in Poland. Associated tests of materials and connections and their results are also included in the paper. Non‐linear behaviour of fasteners is examined in the numerical model. Results obtained from model and experiments are coincident.

An Analytical Study of the Structural Integrity of an LPG Storage Tank under Wind Load

2015 ◽  
Vol 741 ◽  
pp. 115-118 ◽  
Author(s):  
Bong Kwan Park ◽  
Jae Min Kim ◽  
Chang Min Keum ◽  
C. Kim ◽  
Heon Oh Choi
Keyword(s):  
Storage Tank ◽  
Structural Integrity ◽  
Element Model ◽  
Wind Load ◽  
Von Mises Stress ◽  
Shell Elements ◽  
Analytical Technique ◽  
Von Mises ◽  
Design Factors ◽  
Important Design

Since the wall thicknesses of most large LPG storage tanks are thin while their diameters are large, their structural integrity is one of the most important design factors. The tanks are mainly located near the waterfront for efficient transport and accessibility. This leads to exposure to wind loads, which should be considered in the design of the tanks. This paper describes an analytical technique for determining the structural integrity of a 45m diameter-LPG storage tank in the case of a wind load based on API 620 code. A finite element model for the tank was made using shell elements and analyzed under 50 m/s wind. The calculated maximum von-Mises stress was 103 MPa whereas the yield strength of tank’s material is 222 MPa. This result shows that the structural integrity of the tank is assured.

Hull Girder Ultimate Strength of Intact and Damaged Double Hull Tankers

2016 ◽  
Author(s):  
Diogo do Amaral M. Amante ◽  
John Alex Chujutalli ◽  
Segen F. Estefen
Keyword(s):  
Numerical Model ◽  
Ultimate Strength ◽  
Numerical Models ◽  
Experimental Tests ◽  
Small Scale ◽  
Box Girders ◽  
Shell Elements ◽  
Hull Girder ◽  
Damage Scenarios ◽  
Double Hull

The aim of this work is to accomplish an assessment of the hull girder ultimate strength of intact and damaged double hull tankers. First, the paper presents the validation of the numerical model through comparisons with experimental tests of small-scale box girders. The numerical models are represented by shell elements assuming finite membrane strains and large rotations, considering both geometric and material nonlinearities. Simulation results show very good agreement with experimental tests. Then, a numerical model of a double hull tanker was developed and analyzed in the intact and damaged conditions. Several damage scenarios were investigated.

scholarly journals 3D Numerical Simulation of Shield Tunnel Subjected to Swelling Effect Considering the Nonlinearity of Joint Bending Stiffness

2019 ◽  
Author(s):  
Qixiang Yan ◽  
Chuan Zhang ◽  
Wang Wu ◽  
Hongxue Zhu ◽  
Wenbo Yang
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Elastic Shell ◽  
Three Dimensional ◽  
Bending Stiffness ◽  
Shield Tunnel ◽  
Shell Elements ◽  
Swelling Soils ◽  
Internal Forces ◽  
Engineering Projects

In this paper, the authors developed a three dimensional shell-spring numerical model of a shield tunnel, in which the elastic shell elements were adopted to model the segments and the spring models were used for the simulation of the segmental joints. The highlight of this research is that the non-linearity of the joint bending stiffness was taken into consideration, which was first determined through the numerical simulation by using a refined 3D continuum model of the segment-joint structure. The automatic iteration of the joint bending stiffness was achieved through programming with the ANSYS ADPL software. Based on a specific engineering example, a 3D continuum-shell-spring model was established to analyze the internal forces of shield tunnel segmental linings subject to swelling soils. The developed numerical model and its application in the analysis of the internal forces of shield tunnel segmental linings in swelling ground will provide useful reference and guidance for the numerical calculation in similar engineering projects in future.

scholarly journals Numeričko modeliranje međudjelovanja konstrukcije i tekućine kombinacijom metode konačnih elemenata i hidrodinamike izglađenih čestica

2017 ◽  
Author(s):  
◽  
Marina Sunara Kusić
Keyword(s):  
Numerical Model ◽  
Steel Structures ◽  
Model Verification ◽  
Experimental Investigations ◽  
Nonlinear Characteristics ◽  
Experimental Database ◽  
Shell Elements ◽  
Model Based ◽  
Numeric Model ◽  
Steel Flow

Within this paper, a 3D numerical model for the fluid structure interaction under dynamic load, has been developed. Partitioned approach has been used, where the construction and fluid are solved separately and by different methods. For the analysis of construction, a previously developed model based on the finite element method (FEM) has been used, which was improved by introducing the drilling stiffness of the degenerated isoparametric final element of the shell. For the analysis of fluid, a previously developed model based on the method of smoothed particle hydrodynamics (SPH) has been used, which was improved by introducing additional correction of fluid pressures values along the boundaries of the computer domain. The model is primarily developed for simulation of steel structures that can be described by shell elements (water tanks, reservoirs, etc.). The model can be used to describe the main nonlinear characteristics of the construction steel: flow (yield) under compression and tension and evolvent of plasticity. It is also possible to simulate the basic nonlinear characteristics of the fluid (compressibility, viscous flow and turbulence). Experimental investigations of the interaction of open rectangular reservoirs and water on the shake table were performed within this paper. Experimental investigations have contributed to additional knowledge of the real behaviour of shell structures that are in contact with the fluid and exposed to different dynamic loads. In addition, an experimental database for verification of the developed numeric model was created. Numerical tests performed by using a developed numerical model show its reliability and application. Model verification was performed on the example of the results of the experimental investigations performed within the paper but also from the numerical and experimental results from available literature. Finally, the most important conclusions of the conducted investigations are listed.

An Advanced Numerical Model for Single Straight Tube Coriolis Flowmeters

2006 ◽  
Vol 128 (6) ◽  
pp. 1346-1350 ◽  
Author(s):  
Tao Wang ◽  
Roger C. Baker ◽  
Yousif Hussain
Keyword(s):  
Finite Element Method ◽  
Numerical Model ◽  
Sensitivity Factor ◽  
Straight Tube ◽  
Modal Frequency ◽  
Shell Elements ◽  
Structure Interaction ◽  
Coriolis Flowmeter ◽  
Measuring Tube ◽  
Stiffness And Damping

A detailed numerical model has been developed to simulate the single straight tube Coriolis flowmeter, which includes all important practical features. The measuring tube is modeled as fluid-tube interaction elements characterized as mass, stiffness, and damping matrices based on the theories of fluid-structure interaction and finite element method. Other features, such as the inner and outer cases and the driver spring, are modeled as standard ANSYS beam and shell elements and coupled to the measuring tube. The modal frequency and sensitivity factor from experiments are used to validate the model. In particular, our results show that the modal behaviour of the meter can only be adequately modeled if these practical features are included.

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