Papers by Elena Felicia Beznea
InTech eBooks, Mar 16, 2011
Torsion dynamic analysis of a ship hull composite model
CRC Press eBooks, Sep 20, 2011
Shear buckling analysis of the composite plates with cut-outs
RETRACTED: Response of ship hull laminated plates to close proximity blast loads
Computational Materials Science, Feb 1, 2012
... Ionel Chirica Corresponding Author Contact Information , a , E-mail The Corresponding Author ... more ... Ionel Chirica Corresponding Author Contact Information , a , E-mail The Corresponding Author , Doina Boazu a and Elena-Felicia Beznea a. ... The response of elastic structures to time-dependent external excitations, such as sonic boom and blast loadings, is a subject of much ...
Buckling studies on ship hull imperfect composite plates
CRC Press eBooks, Mar 11, 2013
Experimental and Numerical Analysis of Buckling Behaviour of the Ship Plates Made of Composite Materials
Key Engineering Materials, Oct 1, 2008
In this paper, results obtained on buckling behavior of ship deck plates made of composite materi... more In this paper, results obtained on buckling behavior of ship deck plates made of composite materials are presented. The fabrication technologies used in ship structures made of composite materials are mostly based on the hand made. So, the probability to occur material imperfections is too high. The influence of the imperfections on the buckling characteristics of the panels is analyzed. The results obtained so by numerical and by experimental analysis of the composite plates with initial transversal imperfections are compared with the results obtained for the plates made of steel, having the same type of imperfections.
Behavior Analysis of a Ship Structure Made out of Composite Materials
Advanced Materials Research, Feb 1, 2017
. In this paper a parametric static and torsion analysis on a catamaran ship structure made out o... more . In this paper a parametric static and torsion analysis on a catamaran ship structure made out of composites materials is performed. The best solution for material selection is based on specific criteria for certain analysis. For dynamic analysis, the main criteria is to obtain the structure natural frequencies in a range, far from the resonance frequencies produced by the ship propulsion installation, wave loads etc. For static analysis the comparative criteria is to obtain the lowest weight of structure for the same strength. Also, buckling item is other criteria for comparative analysis. The comparative analysis is performed between rule based scantling structure and a FEM based structure for a composite material twin hull deck, in order to reduce the total hull weight. Material used for ship deck structure of the analyzed ship is e-glass polyester.
Fatigue Life Estimation of a Layered Composite Plate
Advanced Materials Research, Feb 1, 2017
This paper presents the FEM approach of fatigue life estimation of a layered composite plate havi... more This paper presents the FEM approach of fatigue life estimation of a layered composite plate having a central elliptical cut-out subjected to time variation loads. Some properties and material data, such as data used for the S-N curve / Wöhler curve of the material, represented in cyclic stress versus number of cycles to failure coordinates, which is required for starting the fatigue analysis, were taken from the OPTIMAT database.The plate analysis was parameterized and modeled with the Shell281 element type. This type of element can be used in a triangular form more efficiently than other types of shell elements available in version 15 of ASYS APDL.Initially, the static analysis was performed to identify the node with the maximum principal stress (hot spots). This node was used for performing the fatigue analysis. The fatigue parameter to estimate fatigue life is cumulative fatigue usage factor. This factor is obtained by adding together all individual usage factors calculated for each variable load that is applied to the analyzed plate. The fatigue usage factor is used to estimate the percentage of life that is consumed after applying the fatigue loads. The value of the usage factor is in the range from 0 to 1.
Influence of the Honeycomb Geometry on the Sandwich Composite Plate Behavior
Advanced Materials Research, Feb 1, 2017
In this paper the influence cell honeycomb geometry on the mechanical behaviour of a composite sa... more In this paper the influence cell honeycomb geometry on the mechanical behaviour of a composite sandwich plate is analyzed. Three cell geometries (circular, hexagonal and square) are static analysed so that to select the best type of honeycomb that will be used in the manufacturing the sandwich plate core. The main aim is to develop approach models of equivalent orthotropic materials to replace the real model of honeycomb core with their properties so that to quickly calculate the sandwich plate made out of composite when is used a finite element analysis code. Geometry and material properties of the honeycomb are delivered by the material provider. Comparative analysis, by using Finite element analysis is performed for all geometries, in the same boundary conditions. Since in the impact loading of the composite sandwich plate the core is mainly loaded to compression, comparative study of the three cell geometries honeycomb was performed for this type of compressive loading. Since the cell is the basic element of the honeycomb core, the calculus is performed for one unit volume of sandwich, concerning also the part of skins.
Fatigue Sensitivity Analysis of a Ship Structural Detail
In the paper, a FEM analysis used for fatigue assessment, based on the rules, was done. The appro... more In the paper, a FEM analysis used for fatigue assessment, based on the rules, was done. The approach for fatigue assessment in the early design stage of the ship structure has been developed. To overcome the challenges due to limited information in the early design stage, generic structural elements and predefined fatigue-critical details were chosen. This allows for the development of a common approach for different ship types, which is also applicable for optimization purpose.
IOP Conference Series: Materials Science and Engineering, 2018
The dynamic behavior of bebonded sandwich plates at the skin/core interface is analysed. The fini... more The dynamic behavior of bebonded sandwich plates at the skin/core interface is analysed. The finite element code COSMOS/M is used to analyse natural frequencies and mode shapes of the sandwich plates with a ellipse shape debonding area. The delamination model has been developed by using the surface-to-surface contact option. In case of surface-tosurface contact, the FE meshes of adjacent plies do no need to be identically. The influence of the diameters ratio of the debonded area, on the modal parameters of clamped sandwich plates is investigated. Parametric calculus of the sandwich plate, having various diameters ratios (Dx/Dy = 0.5; 0.75; 1) for delaminated area, have been considered. It has been observed that all the above mentioned ratios are contributing to the changes in dynamic responses of the sandwich plate.
Influence of the Honeycomb Geometry on the Sandwich Composite Plate Behavior
Advanced Materials Research, 2017
In this paper the influence cell honeycomb geometry on the mechanical behaviour of a composite sa... more In this paper the influence cell honeycomb geometry on the mechanical behaviour of a composite sandwich plate is analyzed. Three cell geometries (circular, hexagonal and square) are static analysed so that to select the best type of honeycomb that will be used in the manufacturing the sandwich plate core. The main aim is to develop approach models of equivalent orthotropic materials to replace the real model of honeycomb core with their properties so that to quickly calculate the sandwich plate made out of composite when is used a finite element analysis code. Geometry and material properties of the honeycomb are delivered by the material provider. Comparative analysis, by using Finite element analysis is performed for all geometries, in the same boundary conditions. Since in the impact loading of the composite sandwich plate the core is mainly loaded to compression, comparative study of the three cell geometries honeycomb was performed for this type of compressive loading. Since th...
Behavior Analysis of a Ship Structure Made out of Composite Materials
Advanced Materials Research, 2017
. In this paper a parametric static and torsion analysis on a catamaran ship structure made out o... more . In this paper a parametric static and torsion analysis on a catamaran ship structure made out of composites materials is performed. The best solution for material selection is based on specific criteria for certain analysis. For dynamic analysis, the main criteria is to obtain the structure natural frequencies in a range, far from the resonance frequencies produced by the ship propulsion installation, wave loads etc. For static analysis the comparative criteria is to obtain the lowest weight of structure for the same strength. Also, buckling item is other criteria for comparative analysis. The comparative analysis is performed between rule based scantling structure and a FEM based structure for a composite material twin hull deck, in order to reduce the total hull weight. Material used for ship deck structure of the analyzed ship is e-glass polyester.
Fatigue Life Estimation of a Layered Composite Plate
Advanced Materials Research, 2017
This paper presents the FEM approach of fatigue life estimation of a layered composite plate havi... more This paper presents the FEM approach of fatigue life estimation of a layered composite plate having a central elliptical cut-out subjected to time variation loads. Some properties and material data, such as data used for the S-N curve / Wöhler curve of the material, represented in cyclic stress versus number of cycles to failure coordinates, which is required for starting the fatigue analysis, were taken from the OPTIMAT database.The plate analysis was parameterized and modeled with the Shell281 element type. This type of element can be used in a triangular form more efficiently than other types of shell elements available in version 15 of ASYS APDL.Initially, the static analysis was performed to identify the node with the maximum principal stress (hot spots). This node was used for performing the fatigue analysis. The fatigue parameter to estimate fatigue life is cumulative fatigue usage factor. This factor is obtained by adding together all individual usage factors calculated for each variable load that is applied to the analyzed plate. The fatigue usage factor is used to estimate the percentage of life that is consumed after applying the fatigue loads. The value of the usage factor is in the range from 0 to 1.
Damping Properties of Magnetorheological Elastomers
Advanced Materials Research, 2017
Magnetorheological elastomers (MREs) are a kind of smart materials, which change the mechanical p... more Magnetorheological elastomers (MREs) are a kind of smart materials, which change the mechanical properties (viscoelastic characteristics) under the magnetic field action. In the paper the determination of damping properties (reactive force) of specimens made out of magnetorheological elastomers is presented. The specimens made out of MREs have been fabricated as a composite with matrix made out of silicone rubber with certain contents of magnetisable particles (carbonyl iron powder). The cylindrical specimens have been tested in compression loading, controlled by an electro-mechanic system. The MRE characteristics of the specimens have been determined in the presence of a magnetic field produced with an electromagnet (coil device). The reactive force occurring in the MRE specimen has been determined on the basis of the measured data during loading. The variation curves of the reactive force versus magnetic field induction are drawn. As a conclusion, the rigidity of the MRE specimen ...
MRE Damping Characteristics Evaluation
Key Engineering Materials, 2016
The paper addresses the study of the damping characteristics estimation and behaviour of the magn... more The paper addresses the study of the damping characteristics estimation and behaviour of the magnetorheological elastomers (MREs) in the absence of magnetic field. This type of material actively changes the size, internal structure and viscoelastic characteristics under the external influences. These particular composite materials whose characteristics can vary in the presence of a magnetic fields are known as smart materials. The feature which causes the variation of properties in magnetic fields is explained by the existence of polarized particles which change the material form by energy absorbing. Damping is a special characteristic that influences the vibratory of the mechanical system. As an effect of this property is the reducing of the vibration amplitudes by dissipating the energy stored during the vibratory moving. The main characteristic that is based on the determination of the damping coefficient is the energy loss, which is the subject of the present paper. Before to start the characteristics determination in the presence of the magnetic field, it is necessary to study these characteristics in the absence of magnetic field. The MRE specimens have been manufactured and tested under the light conditions (non magnetic field). A special experimental test rig was built to investigate the response of the MRE specimens under the charging force. The experimental results show that the loss energy of the MRE specimen can be determined from the charging-discharging curves versus displacement. The results of the MRE specimen are presented in this paper: MRE with feromagnetic particles not exposed in magnetic field during fabrication.
Retraction notice to “Torsional behaviour of the ship hull composite model” [Comput. Mater. Sci. 50 (4) (2011) 1381–1386]
Computational Materials Science, 2015
Torsion dynamic analysis of a ship hull composite model
Sustainable Maritime Transportation and Exploitation of Sea Resources, 2011
Buckling studies on ship hull imperfect composite plates
Analysis and Design of Marine Structures, 2013
Structural Solutions for Ship Hull Plates Strengthening, under Blast Loads
Key Engineering Materials, 2014
The paper presents selected results of a study concerning the protective capacity of ship hull pl... more The paper presents selected results of a study concerning the protective capacity of ship hull plates, made out of layered composite plates. A scenario to evaluate the behaviour of the ship structure plate under blast loading is presented. The nonlinear analysis on a 3-D FEM model by using composite elements was performed. The methodology for the blast pressure charging and the mechanism of the blast wave in free air are given. The space pressure variation is determined by using Friedlander exponential decay equation. According to the methods used in this paper an individual pressure-time history to each element based on its distance from the blast is assigned. The dynamic response of the composite plate is shown.
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Papers by Elena Felicia Beznea