Mohamed Guerich

@article{chaabene_3194,

title = {Experimental Investigation of the Influence of Process Parameters on the Mechanical Properties of Maraging Steel Produced by Electron Beam Melting},

author = {Ameni Chaabene and Slim Ben Elechi and Sami Chatti and Mohamed Guerich and Ated Ben Khalifa},

url = {https://link.springer.com/article/10.1007/s00170-024-14731-0#citeas},

year  = {2024},

date = {2024-12-01},

journal = {International Journal Of Advanced Manufacturing Technology},

volume = {135},

pages = {3865-3882},

abstract = {Maraging steels are used in industries that require high precision due to their exceptional mechanical properties. This paper

presents the impact of ten process parameters on the mechanical properties of maraging steel produced via electron beam

melting (EBM). The parameters studied here include printing orientation, scanning speed, beam power, beam diameter,

line offset, layer thickness, scan strategy, number of contours, preheating temperature, and post-processing. The mechanical

properties evaluated are tensile strength, strain at fracture, elongation at failure, energy density, material hardness, porosity,

and surface morphology. The results showed a significant correlation between these mechanical properties and the EBM

parameters. The highest ultimate tensile stress, determined from the tensile test, was recorded at 1491.51 MPa, corresponding

to an energy density of 64.28 J/mm3. The optimal parameters were identified as a line offset of 0.1 mm, a layer thickness

of 50 ?m, a scanning speed of 2800 mm/s, and a beam power of 15 mA. The energy density during EBM in turn affected

microstructure, porosity, and mechanical properties. Furthermore, the study revealed that aging heat treatment had a considerable

impact on the mechanical properties, with the highest tensile strength observed for a sample that had undergone

aging at 460 °C for 8 h. The results show the critical role of process parameters and aging heat treatment in achieving optimal

mechanical properties in EBM-produced maraging steel M789. These findings contribute to the optimization of this

manufacturing technique for industrial applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mhiri_2886,

title = {Modeling and Analysis of a Macro-fiber Piezoelectric Bimorph Energy Harvester operating in d33-Mode using Timoshenko Theory},

author = {Mohamed Taha Mhiri and Mnaouar Chouchane and Mohamed Guerich and Walid Larbi},

url = {https://www.peeref.com/journals/5764/mechanics-of-advanced-materials-and-structures},

year  = {2024},

date = {2024-04-01},

journal = {Mechanics Of Advanced Materials And Structures},

pages = {1-15},

abstract = {Piezoelectric bimorph cantilevered beams are frequently employed in energy harvesting applications. The use of macro-fiber composites, which combine piezoelectric fibers with rectangular cross-sections and interdigitated electrodes, has significantly enhanced their performance by enabling operation in the 33-mode of piezoelectricity, thereby increasing conversion efficiency. In this paper, the Timoshenko beam theory is applied to overcome the limitations of the Euler-Bernoulli theory in modeling transverse vibrations of harvesters with low slenderness ratios (length to thickness ratios). The mixture rule formulation is applied to determine the equivalent properties of the macro-fiber composite (MFC) structure. The electromechanical properties of a representative volume element (RVE) bounded by two successive interdigitated electrodes are coupled to the overall electro-elastic dynamic model of the structure using the Timoshenko theory. Frequency response functions for the power and tip vibration displacement of the MFC bimorph beam are determined from the model. Experimental data from the literature are used to validate the improved results predicted by the model developed in this paper. A comparative analysis between the electromechanical responses predicted using a model based on Timoshenko and a model based on Euler-Bernoulli theory is conducted showing agreement, for harvesters with large slenderness ratios and discrepancies of up to 30 % for low slenderness ratios. It has also been shown that the model based on Euler-Bernoulli theory overestimates both the mechanical and the electrical responses for low slenderness ratios as the shear and rotary inertia effects are not negligible in this case.},

keywords = {},

pubstate = {online},

tppubtype = {article}

}

@article{benjeddou_892,

title = {Free vibration of actual aircraft and spacecraft hexagonal honeycomb sandwich panels: A practical detailed FE approach},

author = {Ayech Benjeddou and Mohamed Guerich},

url = {http://koreascience.or.kr/article/JAKO201913457808231.page},

year  = {2019},

date = {2019-03-01},

journal = {Advances in Aircraft and Spacecraft Science},

volume = {6},

number = {2},

pages = {169-187},

abstract = {This work presents a practical detailed finite element (FE) approach for the three dimensional (3D) free vibration analysis of actual aircraft and spacecraft type lightweight and thin honeycomb sandwich panels. It consists of calling successively in MATLAB®, via a developed user friendly GUI, a detailed 3D meshing tool, a macro commands language translator and a commercial FE solver (ABAQUS® or ANSYS®). In contrary to the common practice of meshing finely the faces and core cells, the proposed meshing tool represents each wall of the actual hexagonal core cells as a single two dimensional (2D) 4 nodes quadrangular shell element or two 3 nodes triangular ones, while the faces meshes are obtained simply using the nodes at the core faces interfaces. Moreover, as the same 2D FE interpolation type is used for meshing the core and faces, this leads to an automatic handling of their required FE compatibility relations. This proposed approach is applied to a sample made of very thin glass fiber reinforced polymer woven composite faces and a thin aluminum alloy hexagonal honeycomb core. The unknown or incomplete geometric and materials properties are first collected through direct measurements, reverse engineering techniques and experimental FE modal analysis based inverse identification. Then, the free vibrations of the actual honeycomb sandwich panel are analyzed experimentally under different boundary conditions and numerically using different mesh basic cell shapes. It is found that this approach is accurate for the first few modes used for pre design purpose.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{tognevi_77,

title = {A multi-scale modeling method for heterogeneous structures without scale separation using a filter-based homogenization scheme},

author = {Amen Tognevi and Mohamed Guerich and Julien Yvonnet},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/nme.5200},

year  = {2016},

date = {2016-10-01},

journal = {International Journal For Numerical Methods In Engineering},

volume = {108},

number = {1},

pages = {mars-25},

abstract = {A method is proposed to compute the response of highly heterogeneous structures by constructing homogenized models when no scale separation can be assumed. The technique is based on an extended homogenization scheme where the averaging operators are replaced by linear filters to cut off fine scale fluctuations, while maintaining locally varying mechanical fields with larger wavelength. As a result, the constitutive law at an intermediate scale, called mesoscale, arises to be naturally nonlocal by construction, where the kernel operator is fully constructed by computations on the unit cell associated with the microstructure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hoang_51,

title = {Determining the Size of RVE for Nonlinear Random Composites in an Incremental Computational Homogenization Framework},

author = {Trung Hieu Hoang and Mohamed Guerich and Julien Yvonnet},

url = {https://ascelibrary.org/doi/10.1061/%28ASCE%29EM.1943-7889.0001057},

year  = {2016},

date = {2016-05-01},

journal = {Journal Of Engineering Mechanics},

volume = {142},

number = {5},

pages = {4016018.1 -4016018.11},

abstract = {In this paper, the authors address the issue of determining the size of a representative volume element (RVE) in the case of nonlinear random composites with either elastoplastic or elasto-viscoplastic phases. In such a case, the general form of the effective constitutive behavior is not known in advance and the response must be evaluated either by direct numerical computations on the RVE or by an appropriate approximation scheme.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{guerich_2374,

title = {Optimization of Noise Transmission Through Sandwich Structures},

author = {Mohamed Guerich and Samir Assaf},

url = {https://asmedigitalcollection.asme.org/vibrationacoustics/article-abstract/135/5/051010/380063/Optimization-of-Noise-Transmission-Through?redirectedFrom=fulltext},

year  = {2013},

date = {2013-10-01},

journal = {Journal Of Vibration And Acoustics-Transactions Of The Asme},

volume = {135},

number = {5},

pages = {051010},

abstract = {An optimization methodology to increase the noise transmission loss (TL) of damped

sandwich structures is presented. The prediction of the TL uses a numerical tool based on

a finite element formulation for the sandwich plate coupled to a boundary element

method for the acoustic medium. This tool can be used for arbitrarily shaped three-layer

sandwich plates with various boundary conditions and it is well adapted to parametric

and optimization studies. First, a parametric study was conducted to choose the objective

function, the constraints, and the pertinent design variables to use in the optimization

problem which consist in reducing the sound power transmitted by a viscoelastically

damped sandwich plate. Next, by constraining the acoustical behavior of the sandwich panel,

the surface mass of the sandwich structure was minimized. It is shown that a significant

reduction in the transmitted sound power can be achieved by selecting the appropriate

geometric configuration and damping layer material.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{assaf_2375,

title = {Vibration and damping analysis of plates with partially covered damping layers},

author = {Samir Assaf and Mohamed Guerich and Philippe Cuvelier},

url = {https://acta-acustica.edpsciences.org/},

year  = {2011},

date = {2011-03-01},

journal = {Acta Acustica},

volume = {97},

pages = {553 - 568},

abstract = {The constrained-layer damping treatment is widely used to control the resonant response of vibrating structures,

particularly in the automotive and aerospace industries. This technique requires design tools in order to select the

best location, type and thickness of the damping and constraining-layer materials for optimum damping while

minimizing the total weight of the damping treatments. In this study, a numerical tool is presented to analyze the

vibration response of plates partially or fully covered with a constrained viscoelastic damping material. This tool

is based on a finite element approach. The undamped plate structure is modeled using a discrete Kirchhoff theory

(DKT) element. However, a sandwich plate element is specially derived to model the damped plate structure.

This element is formulated in such a way that it is compatible with the DKT element. The natural frequencies

and modal loss factors are derived from the modal strain energy method. The proposed approach is validated

by comparing predictions with the results of various examples published in the literature. Hence, this approach

is shown to predict accurately the damping characteristics of arbitrarily shaped sandwich plates, with different

material properties and boundary conditions, fully or partially covered with constrained viscoelastic layers. The

influence of the damping patch locations and the viscoelastic material's shear modulus on the vibration and

damping characteristics is investigated. To damp the plate effectively using partial coverage, the damping patches

must be distributed appropriately. To select the best damping patch locations, an indicator based on the energy

dissipated through the viscoelastic layer is proposed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{assaf_2845,

title = {Vibration and acoustic response of damped sandwich plates immersed in a light or heavy fluid},

author = {Samir Assaf and Mohamed Guerich and Philippe Cuvelier},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0045794910000805},

year  = {2010},

date = {2010-07-01},

journal = {Computers & Structures},

volume = {88},

number = {13-14},

pages = {870-878},

abstract = {This paper presents a finite element formulation to analyze the vibro-acoustic response of plates with

constrained-layer damping treatment. This formulation takes into account the effects of fluid loading.

The governing coupled structural/acoustic equations of motion are solved using a modal approach combined

with an interpolation technique of the reduced radiation impedance matrix components of the

fluid. The numerical results show the accuracy of the proposed approach. In addition, a parametric study

is carried out to highlight the influence of geometrical and material variables on the damping characteristics,

which could be used as design parameters for the optimization problem.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{assaf_2854,

title = {Numerical Prediction of Noise Transmission Loss through Viscoelastically Damped Sandwich Plates},

author = {Samir Assaf and Mohamed Guerich},

url = {https://journals.sagepub.com/home/jsm},

year  = {2008},

date = {2008-09-01},

journal = {Journal Of Sandwich Structures & Materials},

volume = {10},

number = {5},

pages = {359-384},

abstract = {This study describes the numerical prediction of noise transmission

loss (TL) through sandwich plates subjected to an acoustic plane wave or a diffuse sound field excitation. The sandwich plate considered is made up of a viscoelastic core sandwiched between two elastic faces. The model presented is based on a finite

element formulation for the sandwich plate coupled to a boundary element method for the acoustic medium. The plate formulation is derived from Kirchhoff's theory for the elastic faces and Mindlin's theory for the core. The strain and kinetic energies

of the sandwich plates are written in terms of the mean and relative in-plane displacements of the faces and the transverse deflection of the plate. The diffuse sound field is modeled as a superposition of uncorrelated plane waves with equal amplitude. The vibroacoustic equations obtained are discretized using a triangular

finite element. The accuracy of the present model is demonstrated by comparing it with analytical and experimental results available in the literature. New results on laminated glass showing the effects of temperature on the TL are presented.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{trompette_1396,

title = {An experimental validation of a vibro-acoustic simplified prediction by the use of simplified methods},

author = {Nicolas Trompette and Mohamed Guerich},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0003682X04001434},

year  = {2005},

date = {2005-01-01},

journal = {Applied Acoustics},

volume = {66},

pages = {427- 445.},

abstract = {Predicting the vibro-acoustic behaviour of a structure is usually done by using the well

established finite element (FE) method and boundary element method. This paper presents

a vibro-acoustic prediction case performed on a metal box using less accurate but simplified

methods: sub-structuring for the calculation of the dynamic response of the structure, and a

monopole distribution for the radiated noise calculation. Both are less accurate but faster

methods than previous ones. An experimental validation was performed. It led to the conclusion

that these methods give precise results and are sufficient for the pre-design of structures in

the low frequency domain. However, this conclusion must be moderated by the fact that in

spite of the simplicity of the structure, the FE model had to be adjusted to the experiments

to yield to a result close to the experiments.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{guerich_2847,

title = {A numerical method for vibro-acoustic problems with incompatible finite element meshes using B-Spline functions},

author = {Mohamed Guerich and Mohamed Ali Hamdi},

url = {https://pubs.aip.org/asa/jasa},

year  = {1999},

date = {1999-03-01},

journal = {Journal Of The Acoustical Society Of America},

volume = {105},

number = {3},

pages = {1682-1694},

abstract = {The paper describes a new method for computing fluid-structure coupling with incompatible finite element meshes using cubic B-spline functions (UCBFs).A modal approach is used which has the advantage of computing the individual structure and fluid mode shapes, using independant meshes. In order to compuiter teh fluide-structural coupling forbthe incompatible meshes, it is necessary to interpolate the structure and fluid mode shapes over a common geometric mesh. This mesh is defined by the mesh itself which is also interpolated bu UCBF using a minimum number of geometric control nodes.New structural and fluid meshes are first derived from the geometric mesh by defining two different elemnt multiplicities. An extrapolation algorithm is then developed to deduce the values of fluid and structural functions (displacement and pressure) over the two new meshes. The UCBs are finally used to interpolate mode shapes of fluid and structure from the two previous meshes into a common mesh. Having the two new functions over the same common mesh  provides the fluid-structure coupling for incompatible meshes. The method is illusttrated for 2D and 3D coupled problems corresponding to shells of revolution, plates and 3D shells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}