Restoration and Structural Analysis of an Irregular Byzantine Monument – A Discussion on a Simplifying Analysis Procedure

2021 ◽  
pp. 418-430
Author(s):  
Styliani Papatzani ◽  
Nikolaos Pnevmatikos ◽  
Eleni Zarogianni ◽  
Konstantinos Dimitroulias ◽  
Georgios Tzamalis ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Analysis Procedure

Optimal Design of Composite Lightweight Rollers

1993 ◽  
Author(s):  
K. Bellendir ◽  
Hans A. Eschenauer
Keyword(s):  
Structural Analysis ◽  
Shell Theory ◽  
Analytical Procedure ◽  
Mathematical Optimization ◽  
Optimization Methods ◽  
Analysis Procedure ◽  
Various Boundary Conditions ◽  
Evaluation Models ◽  
Laminate Theory ◽  
Static Behaviour

Abstract A well-aimed layout of fibre-reinforced lightweight rollers does not only require an efficient structural analysis procedure but also the application of structural optimization methods. Therefore, an analytical procedure is introduced for the calculation of the static behaviour of cylindrical shells subject to axisymmetric and/or nonaxisymmetric loads. In the scope of this procedure, arbitrary, unsymmetrical laminates as well as various boundary conditions will be considered. Basis is the shell theory by Flügge enhanced by anisotropic constitutive equations (material law) in the scope of the classical laminate theory. By means of mathematical optimization procedures we then determine optimal lightweight rollers, using different design and evaluation models. For that purpose, coated and uncoated roller constructions as well as hybrid types made of CFRP/GFRP will be applied. Concluding, we will discuss possible improvements and advantages of anisotropic lightweight rollers in contrast to isotropic ones made of steel or aluminium.

Structural Analysis of a Flange Coupling without Clearance

2013 ◽  
Vol 371 ◽  
pp. 652-656
Author(s):  
Danut Zahariea
Keyword(s):  
Numerical Analysis ◽  
Structural Analysis ◽  
3D Model ◽  
Analysis Procedure ◽  
Failure Conditions

In this paper the flange coupling without clearance will be analyzed using CATIA Generative Structural Analysis workbench. The structural analysis procedure will be presented: creating the 3D model, configuring the mesh, applying the restraints, applying the loads (torque), applying the interaction conditions (driving flange-bolts and nuts, bolts and nuts-driven flange), running the numerical analysis and results visualization. Two different systems will be analyzed: the first is a six bolts flange coupling working in nominal conditions, the second is a five bolts flange coupling working in some failure conditions with only five bolts distributed in a six holes flange coupling. In certain conditions the flange coupling design allows the same torque to be transmitted by six, but also by only five bolts. However, the non-uniformity of the five bolts distribution around the six holes flanges will generate some other unwanted phenomena. In this case all the stress and deformations will be non-symmetrically and for the flange coupling that is a rotating coupling this can be one reason for beats phenomenon.

A Modal Analysis Procedure for PWR Fuel Assemblies

2008 ◽  
Author(s):  
Le´o A. Carrilho ◽  
Jayme P. de Gouveˆa
Keyword(s):  
Structural Analysis ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Analysis Procedure ◽  
Normal Operation ◽  
Spacer Grids ◽  
Assembly Design ◽  
Fuel Assemblies

The analysis of vibration effects on the structure of Nuclear Fuel Assemblies was performed by using a 3-D finite element model. A 16×16 Standard Fuel Assembly design was used for this analysis. Since fuel assemblies have a nonlinear behavior during normal operation, due to the interaction between fuel rods and spacer grids, the methodology consisted basically of four steps: a modal analysis for obtaining the natural frequencies, a linear structural analysis for the no sliding stiffness calculation, a nonlinear structural analysis for the sliding stiffness calculation, and a correction factor estimate for natural frequencies obtained directly from the modal analysis. Also, it includes the major calculated stresses associated with the most external thimble tube.

Analysis of Flexibly Connected Steel Frames

1975 ◽  
Vol 2 (3) ◽  
pp. 280-291 ◽  
Author(s):  
M. John Frye ◽  
Glenn A. Morris
Keyword(s):  
Structural Analysis ◽  
Structural Steel ◽  
Stiffness Matrix ◽  
Steel Frames ◽  
Analysis Procedure ◽  
Steel Framing ◽  
Internal Forces ◽  
The Moment ◽  
Pinned Connections ◽  
Fixed End

A procedure is presented for analyzing steel frames with any combination of pinned connections, fixed connections, connections with any specified flexibility characteristics, or any of seven commonly used connection types. A method is outlined for expressing, in a nondimensional form, the moment–rotation characteristics for all connections of a given type. The dimensionless relationships are listed for the commonly used structural steel framing connection types. The incorporation of connection deformations into a linear structural analysis, by modifying the stiffness matrix and fixed-end-force vectors for each member, is demonstrated.An iterative nonlinear analysis procedure is described in which repeated modifications are made to assumed flexibility characteristics for all connections in a structure. When a suitable set of connection flexibility characteristics has been arrived at, a single analysis is performed to determine the correct structural deflections and internal forces.

A Simple Time Domain Structural Redundancy Analysis Procedure for Semi-Submersibles

2007 ◽  
Author(s):  
Partha Chakrabarti ◽  
Manoj K. Maiti
Keyword(s):  
Structural Analysis ◽  
Nonlinear Analysis ◽  
Time Domain ◽  
Redundancy Analysis ◽  
Time History ◽  
Analysis Procedure ◽  
Total Force ◽  
Diffraction Radiation ◽  
Wave Loading ◽  
Wave Load

Offshore design codes like ABS and IMO require some level of redundancy in semi-submersible drilling vessels to withstand the loss of a slender bracing member without overall collapse of the structure, similar to fixed structures. Wave induced dynamic forces on semi-submersibles include hydrodynamic forces on ‘large body’, and inertia forces due to rigid body motions in six degrees of freedom. The amplitudes and phases of each component of the motion are important in defining the total force. Therefore, unlike static ‘pushover’ type analysis used in a relatively dynamically insensitive fixed jacket structure, semi-submersibles require nonlinear dynamic redundancy analysis in the time domain to determine the safety against collapse due to environmental loading. A simple time domain nonlinear analysis procedure is suggested in this study to capture the realistic behavior of the structure under wave loading. Dynamic loads are generated from hydrodynamic analysis of the floating body using a diffraction-radiation analysis program which assumes that the wave excitation is harmonic and so is the response. These loads are transferred to the structural analysis model. Each wave frequency is analyzed to produce a pair of loading conditions — ‘in-phase’ and ‘out of phase’. Combining these two components, a time history of the wave loading is created. In nonlinear structural analysis, first static loads are applied. Then wave load time history is applied for a few wave cycles in small increments. Results show that nonlinear analysis for one single cycle or two can usually predict the safety against collapse. If the analysis continues for a cycle or two, the structure passes the redundancy test. If it does not, the structure has a deficiency that needs to be addressed.

Lateral load analysis of three-dimensional flat plate structures

1985 ◽  
Vol 12 (2) ◽  
pp. 351-361 ◽  
Author(s):  
M. Chislett ◽  
Glenn Morris
Keyword(s):  
Structural Analysis ◽  
Flat Plate ◽  
Three Dimensional ◽  
Shear Walls ◽  
Floor Plate ◽  
Analysis Procedure ◽  
Plate Structures ◽  
Stiffness Matrices ◽  
Plate Elements ◽  
Load Analysis

A procedure is described for performing a linear structural analysis of laterally loaded three-dimensional flat plate structures, with or without shear walls. The structure is assumed to be comprised of column, shear wall, and floor plate elements. To minimize storage requirements for the computer program that performs the analysis, the flat plate floors are assumed to act as rigid in-plane diaphragms. The shear walls are modeled as columns for in-plane bending and as wide beams for out-of-plane bending.Dimensionless stiffness matrices for floor plate elements with four different column width – span ratios have been evaluated using a finite element analysis and incorporated into the structural analysis computer program. Lagrange interpolation is used to evaluate the stiffness matrices for floor plate elements with any specified column width – span ratio. In assembling the structure stiffness matrix, the floor plate nodes along the boundaries between floor panels are condensed off.Examples are presented to demonstrate the accuracy and economy of the analysis procedure and to illustrate the influence of column width – span ratio and plate width on the behavior of the structure.The procedure is the first phase in the development of an iterative analysis procedure that will model the nonlinear behavior of the flat plate structures due to cracking at the column–plate boundary. Key words: flat plate, structural analysis, slab, lateral load analysis.

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