Modeling Group

@article{taleb_1836,

title = {A Flexible Deep Learning Method for Energy Forecasting},

author = {Ihab Taleb and Guillaume Guérard and Nga Nguyen and Frédéric Fauberteau},

url = {https://www.mdpi.com/1996-1073/15/11/3926},

year  = {2022},

date = {2022-05-01},

journal = {Energies},

volume = {15},

number = {11},

pages = {3926},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{maarouf_1803,

title = {Characteristics/finite element analysis for two incompressible fluid flows with surface tension using level set method},

author = {Sarra Maarouf and Christine Bernardi and Driss Yakoubi},

url = {https://www.sciencedirect.com/science/article/pii/S0045782522001530},

year  = {2022},

date = {2022-03-01},

journal = {Computer Methods In Applied Mechanics And Engineering},

volume = {394},

pages = {114843},

abstract = {In this paper, we present and analyze a finite element level set method based on the method of characteristics for two phase

flow. Surface tension effects are taken into account by the CSF approach. We first write the variational formulation of the problem and investigate its well-posedness. Next, for the discretization, a first order method of characteristics approach for the

evolution of the level set function and for the material derivative of the velocity is used. The velocity and pressure unknowns

are discretized by P2? P1 Taylor-Hood finite elements. Then, in each time step, the interface transport is decoupled from the

Navier-Stokes equations. Well-posedness results for subproblems in this decoupled discrete problem are derived. Furthermore,

under high regularity assumptions, we state error estimates for our scheme. Ultimately, three computational examples illustrate

the performance of the proposed method.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{gueye_thiam_2098,

title = {3D Printed and Conventional Membranes?A Review},

author = {Baye Gueye Thiam and Anouar El Magri and Hamidreza Vanaei and Sébastien Vaudreuil},

url = {https://doi.org/10.3390/polym14051023},

year  = {2022},

date = {2022-03-01},

journal = {Polymers},

volume = {14},

number = {5},

pages = {1023},

abstract = {Polymer membranes are central to the proper operation of several processes used in a wide range of applications. The production of these membranes relies on processes such as phase inversion, stretching, track etching, sintering, or electrospinning. A novel and competitive strategy in membrane production is the use of additive manufacturing that enables the easier manufacture of tailored membranes. To achieve the future development of better membranes, it is necessary to compare this novel production process to that of more conventional techniques, and clarify the advantages and disadvantages. This review article compares a conventional method of manufacturing polymer membranes to additive manufacturing. A review of 3D printed membranes is also done to give researchers a reference guide. Membranes from these two approaches were compared in terms of cost, materials, structures, properties, performance. and environmental impact. Results show that very few membrane materials are used as 3D-printed membranes. Such membranes showed acceptable performance, better structures, and less environmental impact compared with those of conventional membranes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{deteix_1802,

title = {A new energy stable fractional time stepping scheme for the Navier-Stokes/Allen-Cahn diffuse interface model},

author = {Jean Deteix and Gerard Lionel Ndetchoua Kouamoa and Driss Yakoubi},

url = {https://www.sciencedirect.com/science/article/pii/S0045782522001104},

year  = {2022},

date = {2022-02-01},

journal = {Computer Methods In Applied Mechanics And Engineering},

volume = {393},

pages = {114759},

abstract = {In this work, we present an original time-discrete formulation of the coupled equations relating the velocity and pressure

of an unsteady flow of two immiscible fluids and the Allen-Cahn equation describing the interface between both of them. We

first prove this time-discrete formulation (based on the concept of coupled projection scheme (Deteix et al., 2014)) to be well

posed and energy stable. We then propose a new family of iterative schemes for the actual approximation of solutions. We

complete this work with numerical tests illustrating the order of accuracy and applying the new scheme on the well known

rising bubble benchmark.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2095,

title = {Numerical Prediction for Temperature Profile of Parts Manufactured using Fused Filament Fabrication},

author = {Hamidreza Vanaei and Sofiane Khelladi and Deligant Michael and Mohammadali Shirinbayani and Abbas Tcharkhtchi},

url = {https://doi.org/10.1016/j.jmapro.2022.02.042},

year  = {2022},

date = {2022-02-01},

journal = {Journal Of Manufacturing Processes},

volume = {76},

number = {0},

pages = {548-558},

abstract = {Bonding of parts produced by fused filament fabrication (FFF) significantly depends on the temperature profile of filaments depositing one top of each other. It is necessary to evaluate the temperature profile during fabrication of structures using both theoretical and experimental approaches. This work describes the overall heat transfer (using finite volume method) that exists in such a process by taking into account the possible phenomena that are developing during the manufacturing sequence: conduction between filaments, conduction between filament and support, and convection with the environment. Although the developed model is general and applicable to both amorphous and semi-crystalline polymers and/or composites, the recordings of temperature variation at the interface of adjacent filaments of a printed vertical wall of PLA illustrated good agreement by implementing very small K-type thermocouples in parallel. It is particularly concerning the occurrence of re-heating peaks during the deposition of new filaments onto previously deposited ones. The sensitivity of the developed code to the operating conditions is shown by variation of several parameters. This makes it easy to apply it for optimization purposes. Theoretical modeling and experimental data presented in this study help better understanding of heat transfer existing in polymer/composite additive manufacturing, and can be valuable to predict more accurately the bond quality and apply the obtained findings for further steps.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{el_haddad_1795,

title = {A projection scheme for phase change problems with convection},

author = {Mireille El Haddad and Youssef Belhamadia and Jean Deteix and Driss Yakoubi},

url = {https://www-sciencedirect-com.acces.bibl.ulaval.ca/science/article/pii/S0898122122000013?via%3Dihub},

year  = {2022},

date = {2022-01-01},

journal = {Computers & Mathematics With Applications},

volume = {108},

number = {1},

pages = {109-122},

abstract = {Numerical modeling of phase change problems with convection is known to be computationally expensive. The main challenge comes from the coupling between Navier-Stokes and heat energy equations. In this paper, we develop a new scheme for phase change problems based on a projection method. The proposed method reduces the size of the system by splitting the temperature, the velocity, and the pressure fields while preserving the accuracy of the simulations. A single-domain approach using a variant of the enthalpy-porosity formulation is employed. Incompressible Navier-Stokes problem with Boussinesq approximation for thermal effects in solid and liquid regions is considered. We regularize the discontinuous variables such as latent heat and material properties by a continuous and differentiable hyperbolic tangent function. The robustness and effectiveness of the proposed scheme are illustrated by comparing the numerical results with numerical and experimental benchmark},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{gurcan_1825,

title = {Phase and amplitude evolution in the network of triadic interactions of the Hasegawa-Wakatani system},

author = {Özgür Gürcan and Johan Anderson and Sara Moradi and Alessandro Biancalani and Pierre Morel},

url = {https://aip.scitation.org/doi/10.1063/5.0089073},

year  = {2022},

date = {2022-01-01},

journal = {Physics Of Plasmas},

volume = {29},

number = {5},

pages = {052306},

abstract = {The Hasegawa-Wakatani system, commonly used as a toy model of dissipative drift waves in fusion devices, is revisited with considerations

of phase and amplitude dynamics of its triadic interactions. It is observed that a single resonant triad can saturate via three way phase

locking, where the phase differences between dominant modes converge to constant values as individual phases increase in time. This allows

the system to have approximately constant amplitude solutions. Non-resonant triads show similar behavior only when one of its legs is a

zonal wave number. However, when an additional triad, which is a reflection of the original one with respect to the y axis is included, the

behavior of the resulting triad pair is shown to be more complex. In particular, it is found that triads involving small radial wave numbers

(large scale zonal flows) end up transferring their energy to the subdominant mode which keeps growing exponentially, while those involving

larger radial wave numbers (small scale zonal flows) tend to find steady chaotic or limit cycle states (or decay to zero). In order to study the

dynamics in a connected network of triads, a network formulation is considered, including a pump mode, and a number of zonal and non-

zonal subdominant modes as a dynamical system. It was observed that the zonal modes become clearly dominant only when a large number

of triads are connected. When the zonal flow becomes dominant as a ?collective mean field,? individual interactions between modes become

less important, which is consistent with the inhomogeneous wave-kinetic picture. Finally, the results of direct numerical simulation are dis-

cussed for the same parameters, and various forms of the order parameter are computed. It is observed that nonlinear phase dynamics results

in a flattening of the large scale phase velocity as a function of scale in direct numerical simulations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mousavi_nejad_2093,

title = {3D Bioprinting of Polycaprolactone-Based Scaffolds for Pulp-Dentin Regeneration: Investigation of Physicochemical and Biological Behavior},

author = {Zohre Mousavi Nejad and Ali Zamanian and Maryam Saeidifar and Hamidreza Vanaei and Mehdi Salar Amoli},

url = {https://doi.org/10.3390/polym13244442},

year  = {2021},

date = {2021-12-01},

journal = {Polymers},

volume = {13},

number = {24},

pages = {4442},

abstract = {In this study, two structurally different scaffolds, a polycaprolactone (PCL)/45S5 Bioglass (BG) composite and PCL/hyaluronic acid (HyA) were fabricated by 3D printing technology and were evaluated for the regeneration of dentin and pulp tissues, respectively. Their physicochemical characterization was performed by field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), contact angle, and compressive strength tests. The results indicated that the presence of BG in the PCL/BG scaffolds promoted the mechanical properties, surface roughness, and bioactivity. Besides, a surface treatment of the PCL scaffold with HyA considerably increased the hydrophilicity of the scaffolds which led to an enhancement in cell adhesion. Furthermore, the gene expression results showed a significant increase in expression of odontogenic markers, e.g., dentin sialophosphoprotein (DSPP), osteocalcin (OCN), and dentin matrix protein 1 (DMP-1) in the presence of both PCL/BG and PCL/HyA scaffolds. Moreover, to examine the feasibility of the idea for pulp-dentin complex regeneration, a bilayer PCL/BG-PCL/HyA scaffold was successfully fabricated and characterized by FESEM. Based on these results, it can be concluded that PCL/BG and PCL/HyA scaffolds have great potential for promoting hDPSC adhesion and odontogenic differentiation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{chami_1564,

title = {Thermodynamic characterization of mixed gas hydrates in the presence of cyclopentane as guest molecule for an application in secondary refrigeration},

author = {Nada Chami and Sabrina Bendjenni and Pascal Clain and Véronique Osswald and Anthony Delahaye and Laurence Fournaison and Didier Dalmazzone},

url = {https://www.sciencedirect.com/science/article/pii/S0009250921003559},

year  = {2021},

date = {2021-11-01},

journal = {Chemical Engineering Journal},

volume = {244},

number = {-},

pages = {116790},

abstract = {Gas hydrates have drawn the attention of many scientists because of their potential role in energy applications. By using some thermodynamic promoters, it is possible to form hydrates at reduced pressure and near ambient temperature, which are suitable formation conditions for most industries. In this study, a high pressure micro differential scanning calorimeter was used to measure the dissociation conditions of mixed cyclopentane (c-C5H10) + CO2 hydrates in the system composed of liquid water + liquid hydrocarbon + hydrate + vapour, in a pressure range of 0 to 4.3 MPa in a temperature range of 280 to 292 K. The analysis of the heat flow curve allowed the direct determination of the dissociation enthalpy of c-C5H10 + CO2 hydrates (e.g., ?H=462.5±1.5 kJ. kg-1 water at equilibrium pressure 0.25 MPa) and the average mass heat capacity of c-C5H10 + CO2 hydrates in a temperature range o 277.9-281.2 K (CpH = 1479.09 ± 137.43 J. K-1. kg-1 hydrate at 0.25 MPa).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vlad_1713,

title = {A linear benchmark between HYMAGYC, MEGA and ORB5 codes using the NLED-AUG test case to study Alfvénic modes driven by energetic particles},

author = {Gregorio Vlad and Xin Wang and Francesco Vannini and Sergio Briguglio and Nakia Carlevaro and Matteo Valerio Falessi and Giuliana Fogaccia and Valeria Fusco and Fulvio Zonca and Alessandro Biancalani and Alberto Bottino and Thomas Hayward-Schneider and Philipp Walter Lauber},

url = {https://doi.org/10.1088/1741-4326/ac2522},

year  = {2021},

date = {2021-11-01},

journal = {Nuclear Fusion},

volume = {61},

number = {1},

pages = {116026},

abstract = {One of the major challenges in magnetic confinement thermonuclear fusion research concerns

the confinement of the energetic particles (EPs) produced by fusion reactions and/or by

additional heating systems. In such experiments, EPs can resonantly interact with the shear

Alfvén waves. In the frame of the EUROfusion 2019-2020 Enabling Research project

?multi-scale energetic particle transport in fusion devices' (MET), a detailed benchmark

activity has been undertaken among few of the state-of-the-art codes available to study the

self-consistent interaction of an EP population with the shear Alfvén waves. In this paper

linear studies of EP driven modes with toroidal mode number n = 1 will be presented, in real

magnetic equilibria and in regimes of interest for the forthcoming generation devices (e.g.

ITER, JT-60SA, DTT). The codes considered are HYMAGYC, MEGA, and ORB5, the first

two being hybrid MHD-gyrokinetic codes (bulk plasma is represented by MHD equations,

while the EP species is treated using the gyrokinetic formalism), the third being a global

electromagnetic gyrokinetic code. The so-called NLED-AUG reference case has been

considered, both for the peaked on-axis and peaked off-axis EP density profile cases, using its

shaped cross section version. Comparison of the spatial mode structure, growth rate and real

frequency of the modes observed will be considered in detail. The dependence of mode

characteristics when several parameters are varied, as, e.g. the ratio between EP and bulk ion

density and EP temperature, will be presented. A remarkable agreement is observed among the

three codes for the peaked off-axis case, obtaining all of them a TAE localized close to the

magnetic axis. On the other hand, some differences are observed when considering the peaked

on-axis case, where two modes are observed (a TAE localized in the radial external region, and

an RSAE around mid-radius). A careful analysis of the stability of this equilibrium, in

particular by varying self-consistently the EP drive, will allow to reconcile the results of the

three codes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{guerard_1732,

title = {Isolated Areas Consumption Short-Term Forecasting Method},

author = {Guillaume Guérard and Hugo Pousseur and Ihab Taleb},

url = {https://www.mdpi.com/1996-1073/14/23/7914},

year  = {2021},

date = {2021-11-01},

journal = {Energies},

volume = {14},

number = {23},

pages = {7914},

abstract = {Forecasting consumption in isolated areas represents a challenging problem typically resolved using deep learning or huge mathematical models with various dimensions. Those models require expertise in metering and algorithms and the equipment needs to be frequently maintained. In the context of the MAESHA H2020 project, most of the consumers and producers are isolated. Forecasting becomes more difficult due to the lack of external data and the significant impact of human behaviors on those small systems. The proposed approach is based on data sequencing, sequential mining, and pattern mining to infer the results into a Hidden Markov Model. It only needs the consumption and production curve as a time series and adapts itself to provide the forecast. Our method gives a better forecast than other prediction machines and deep-learning methods used in literature review.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{braghini_1820,

title = {Effects of Hidden Opinion Manipulation in Microblogging Platforms},

author = {Giulia Braghini and Francesco Salvarani},

url = {https://www.worldscientific.com/doi/abs/10.1142/S0219525921500090},

year  = {2021},

date = {2021-11-01},

journal = {Advances In Complex Systems},

volume = {24},

number = {5},

pages = {2150009},

abstract = {This paper studies a model for describing opinions' evolution in a community linked by microblogging directed network systems. The network can evolve in time by means of the creation and the deletion of some connections. When a connexion is created, the individuals have access to the whole history of posts written by the corresponding author and, when a connexion is destroyed, all the posts written by the corresponding author become invisible. The agents' opinions are described by a set of continuous opinion variables in the closed interval  Omega=[-1,1]. They represent the agreement (or disagreement) of the corresponding agent with respect to a binary question (such as a referendum or an election with two candidates). The model takes into account the effects on public opinion caused by the sign and the intensity of the initial opinions of the agents, their activity in microblogging platforms the presence of leaders and the possible manipulations of the visibility of the posts by the microblogging platform owner. The model is written as a system of integro-differential equations and simulated by using a Runge-Kutta method. We show that hidden manipulation can have an important impact on the public opinion formation and that very mild interventions of the network owner may induce major effects on the population. In our simulations, the effect of hidden manipulation is shown to be more efficient in driving the public opinion than the action of a leader, in the case of bounded confidence models and for short-time intervals.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2094,

title = {In-Process Monitoring of Temperature Evolution during Fused Filament Fabrication: A Journey from Numerical to Experimental Approaches},

author = {Hamidreza Vanaei and Mohammadali Shirinbayani and Deligant Michael and Sofiane Khelladi and Abbas Tcharkhtchi},

url = {https://doi.org/10.3390/thermo1030021},

year  = {2021},

date = {2021-10-01},

journal = {Thermo},

volume = {1},

number = {3},

pages = {332-360},

abstract = {Fused filament fabrication (FFF), an additive manufacturing technique, unlocks alternative possibilities for the production of complex geometries. In this process, the layer-by-layer deposition mechanism and several heat sources make it a thermally driven process. As heat transfer plays a particular role and determines the temperature history of the merging filaments, the in-process monitoring of the temperature profile guarantees the optimization purposes and thus the improvement of interlayer adhesion. In this review, we document the role of heat transfer in bond formation. In addition, efforts have been carried out to evaluate the correlation of FFF parameters and heat transfer and their effect on part quality. The main objective of this review paper is to provide a comprehensive study on the in-process monitoring of the filament's temperature profile by presenting and contributing a comparison through the literature.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{augias_1604,

title = {USoM platform. Proposal for an international and transdisciplinary interactive tool for centralization and anthropological exchange around human remains},

author = {Anais Augias and Sofiane Ben Amor and Philippe Charlier and Guillaume Guérard},

url = {https://www.sciencedirect.com/science/article/pii/S2352552521000542},

year  = {2021},

date = {2021-09-01},

journal = {ETHICS, MEDICINE AND PUBLIC HEALTH},

volume = {18},

pages = {100677},

abstract = {Background



In a previous article related to ethical reflection around the study of human remains and their biological products in archaeological, ethnographic and museum contexts, a general scientific isolation - going against the common interest and leading to certain forms of misconduct - had been raised. It appeared a real need to act in the direction of transparency and a transdisciplinary union.

Methodology



This conclusion led to further reflection on the strengths and technical creation of a tool dedicated to the exchange between sciences relating to the study of man.

Results/Discussion



We propose the creation of a platform dedicated to all international scientific actors whose issues are related to research on humans. This involves proposing the development of a participatory/collaborative virtual platform on which scientific organizations would exchange their study materials, their samples, their tools, their knowledge, their reflections and hypotheses and then the resulting data in order to no longer work in isolation.

Conclusion/Perspectives



This multidisciplinary vision to the study of Man, without spatial or chronological boundaries, will be a contribution to each of the disciplines involved and the benefits of this platform are multiple. However, this coalition approach exposes academic, technical and legal difficulties and represents a real challenge because it requires profound changes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{jaffal-moutarda_1356,

title = {Global existence of the 3D rotating second grade fluid system},

author = {Basma Jaffal-Moutarda},

url = {https://content.iospress.com/articles/asymptotic-analysis/asy201644},

year  = {2021},

date = {2021-08-01},

journal = {Asymptotic Analysis},

volume = {124},

number = {3-4},

pages = {259-290},

abstract = {We consider the equations of a rotating incompressible non-Newtonian fluid flow of grade two in a three dimensional torus. We prove two different results of global existence of strong solutions. In the first case, we consider that the elasticity coefficient ? is arbitrary and we suppose that the third components of the vertical average of the initial data and of the forcing term are small compared to the horizontal components. In the second case, we consider a forcing term and initial data of arbitrary size but we restrict the size of ?. In both cases, we show that the limit system is composed of a linear system and a second grade fluid system with two variables and three components.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{bobbia_1682,

title = {The coupling method in extreme value theory},

author = {Benjamin Bobbia and Clément Dombry and Davit Varron},

url = {https://projecteuclid.org/journals/bernoulli/volume-27/issue-3/The-coupling-method-in-extreme-value-theory/10.3150/20-BEJ1293.short},

year  = {2021},

date = {2021-08-01},

journal = {Bernoulli},

volume = {27},

number = {3},

pages = {1824-1850},

abstract = {A coupling method is developed for univariate extreme value theory, providing an alternative to the use of the tail empirical/quantile processes. We emphasize the Peak-over-Threshold approach that approximates the distribution above high threshold by the Generalized Pareto Distribution (GPD) and compare the empirical distribution of exceedances to the empirical distribution associated with the limit GPD model. Sharp bounds for their Wasserstein distance in the second order Wasserstein space are provided. As an application, we recover standard results on the asymptotic behavior of the Hill estimator, the Weissman extreme quantile estimator or the probability weighted moment estimators, shedding some new light on the theory.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{kallel_1585,

title = {Driving force for shape memory effect of polymers},

author = {Achraf Kallel and Abir Ben Abdallah and Fehmi Gamaoun and Abbas Tcharkhtchi and Hachmi BenDaly and Joseph Fitoussi},

url = {https://link.springer.com/article/10.1007/s10965-021-02637-4},

year  = {2021},

date = {2021-07-01},

journal = {Journal Of Polymer Research},

volume = {28},

number = {10},

pages = {308},

abstract = {In this study, we aim to evaluate the shape memory effect of a Poly (Caprolactone) (PCL) (40%) and a Styrene-Butadiene-Styrene (SBS) (60%) blend. Shape memory cycle tests are performed at different temperatures to detect the best recovery rate. Under appropriate temperature, the blend recovers substantially its original shape. To study the recovery rate evolution, multi cycle tests are realized with controlled temperature. The results indicate that the shape memory effect growths when the number of cycle increases. The stored energy acts as a driving force to bring the polymer to its permanent shape after each loading cycle. Then, an original method is proposed to measure the stress-strain evolution during the recovery. With a variable temperature, no standard test can follow the stress-strain evolution. This test is needed to validate the behavior model.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hamdache_1579,

title = {Macroscopic limit of the kinetic Bloch equation},

author = {Kamel Hamdache and Djamila Hamroun},

url = {https://www.aimsciences.org/article/doi/10.3934/krm.2021015},

year  = {2021},

date = {2021-06-01},

journal = {Kinetic And Related Models},

volume = {14},

number = {3},

pages = {541-570},

abstract = {This work concerns the existence of solution of the kinetic spinor Boltzmann equation as well as the asymptotic behavior of such solution when ??0, that is when the time relaxation of the spin-flip collisions is very small in comparison to the time relaxation parameter of the collisions with no spin reversal. Due to the lack of regularity of the weak solution, the switching term H?×M? is not stable under the weak convergences. Hence we establish new estimates of the so},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{venkateswaran_1788,

title = {An optimal design of a flexible piping inspection robot},

author = {Swaminath Venkateswaran and Damien Charles Chablat and Pol Hamon},

url = {https://asmedigitalcollection.asme.org/mechanismsrobotics/article-abstract/13/3/035002/1096922/An-Optimal-Design-of-a-Flexible-Piping-Inspection},

year  = {2021},

date = {2021-06-01},

journal = {Journal Of Mechanisms And Robotics-Transactions Of The Asme},

volume = {13},

number = {3},

pages = {035002},

abstract = {This study presents an optimization approach for the design of a piping inspection robot. A rigid bio-inspired piping inspection robot that moves like a caterpillar was designed and developed at LS2N, France. By the addition of tensegrity mechanisms between the motor modules, the mobile robot becomes flexible to pass through the bends. However, the existing motor units prove to be oversized for passing through pipe bends at 90 deg. Thus, three cascading optimization problems are presented in this article to determine the sizing of robot assembly that can overcome such pipe bends. The first problem deals with the identification of design parameters of the tensegrity mechanism based on static stability. Followed by that, in the second problem, the optimum design parameters of the robot modules are determined for the robot assembly without the presence of leg mechanisms. The third problem deals with the determination of the size of the leg mechanism for the results of the two previous optimization problems. A digital model of the optimized robot assembly is then realized using cad software.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{yakoubi_1678,

title = {Analysis of a time--discrete scheme for the Navier-Stokes/Allen-Cahn model},

author = {Driss Yakoubi and Jean Deteix and Gerard Lionel Ndetchoua Kouamoa},

url = {https://www.sciencedirect.com/science/article/pii/S0022247X20309793?via%3Dihub},

year  = {2021},

date = {2021-04-01},

journal = {Journal Of Mathematical Analysis And Applications},

volume = {496},

number = {2},

pages = {124816},

abstract = {This paper address the existence and uniqueness, in suitable functional spaces, of the solution of a non linear system of equations originating from the implicit time discretization of the coupled unsteady Navier-Stokes and Allen-Cahn equations. This result is based on the convergence analysis of an original stabilized fixed point algorithm, from which we also get a maximum principle. Numerical experiments are performed to illustrate the influence of the implicit formulation in comparison to a simpler approach based on a semi-explicit time scheme.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{bobbia_1684,

title = {Extreme quantile regression in proportional tail framework},

author = {Benjamin Bobbia and Clément Dombry and Davit Varron},

url = {http://rmi.ge/transactions/TRMI-volumes/175-1/175-1.htm},

year  = {2021},

date = {2021-04-01},

journal = {Transactions of A. Razmadze Mathematical Institute, In press},

volume = {175},

number = {1},

pages = {13-32},

abstract = {We revisit the model of heteroscedastic extremes initially introduced by Einmahl et al. (JRSSB, 2016) to describe the evolution of a non stationary sequence whose extremes evolve over time and adapt it into a general extreme quantile regression framework. We provide estimates for the extreme value index and the integrated skedasis function and prove their asymptotic normality. Our results are quite similar to those developed for heteroscedastic extremes but with a different proof approach emphasizing coupling arguments. We also propose a pointwise estimator of the skedasis function and a Weissman estimator of the conditional extreme quantile and prove the asymptotic normality of both estimators.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{chablat_1789,

title = {Workspace analysis in the design parameter space of a 2-dof spherical parallel mechanism for a prescribed workspace: Application to the otologic surgery},

author = {Damien Charles Chablat and Guillaume Michel and Philippe Bordure and Swaminath Venkateswaran and Ranjhan Jha},

url = {https://www.sciencedirect.com/science/article/pii/S0094114X20304419},

year  = {2021},

date = {2021-03-01},

journal = {Mechanism And Machine Theory},

volume = {157},

number = {3},

pages = {104224},

abstract = {During Otologic surgery, and more broadly during microsurgery, the surgeon encounters several difficulties due to the confined spaces and micro-manipulations. The purpose of the paper is to design a robot with a prescribed regular workspace shape to handle an endoscope to assist the Otologic surgery. A spherical parallel mechanism with two degrees of freedom is analysed in its design parameter space. This mechanism is composed of three legs (2USP-U) to connect the base to a moving platform connected to a double parallelogram to create a remote center of motion (RCM). Its kinematic properties, i.e. the singularity locus and the number of direct kinematic solutions, are investigated. For some design parameters, non-singular assembly modes changing trajectories may exist and have to be investigated inside the prescribed regular workspace shape. Two sets of design parameters are presented with their advantages and disadvantages.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ben_abdallah_1269,

title = {Molecular weight influence on shape memory effect of shape memory polymer blend ( poly(caprolactone)/styrene-butadiene-styrene )},

author = {Abir Ben Abdallah and Fehmi Gamaoun and Achraf Kallel and Abbas Tcharkhtchi},

url = {https://onlinelibrary.wiley.com/doi/10.1002/app.49761},

year  = {2021},

date = {2021-02-01},

journal = {Journal Of Applied Polymer Science},

volume = {138},

number = {5},

pages = {49761},

abstract = {The shape memory effect (SME) does not only concern the macroscopic structure. It concerns also the polymer structure at morphological, macromolecular, and molecular scales. This effect may depend on different physicochemical properties like morphology heterogeneity, chain rigidity, steric hindrance, chain polarity, free volume, cross-linking or entanglement density, molecular shape and weight, and so on. Hence, finding the relationship between the SME and these properties is very important. This can help to obtain the knowledge about the phenomenon origin and mechanism. One of the basic polymer properties, which can have direct SME, may be the molecular weight (Mw). The question here is: If the Mw of a shape memory polymer (SMP) changes, for different reasons like degradation, what will be the effect of this change on its SME. In order to answer to this question, the investigation is focused on an SMP blend of 40% poly(?-caprolactone) (PCL) and 60% styrene-butadiene-styrene (SBS). Then, enzymatic hydrolysis is performed on this blend to change its Mw. It is shown that this change is only related to the variation in the Mw of PCL. After that, different samples with a distinct average Mw are prepared and characterized by various experimental methods. Shape memory tests are performed on these blends, and the recovery rate (Rr) for each of them is determined. It is found that when Mw of PCL decreases, its degree of crystallinity, its glass transition, and its melting temperatures, corresponding to the PCL phase, increase. However, the elongation at break of the blend declines with the reduction in Mw. The tests show that the alteration in the blend's Mw influences its SME. Indeed, Rr of the (PCL/SBS) mixture drops with the decrease in Mw of PCL.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pouradier_duteil_1268,

title = {Kinetic approach to the collective dynamics of the rock paper scissors binary game},

author = {Nastassia Pouradier Duteil and Francesco Salvarani},

url = {https://www.sciencedirect.com/science/article/pii/S0096300320304549#!},

year  = {2021},

date = {2021-01-01},

journal = {Applied Mathematics And Computation},

volume = {388},

pages = {125496},

abstract = {This article studies the kinetic dynamics of the rock-paper-scissors binary game. We first prove existence and uniqueness of the solution of the kinetic equation and subsequently we prove the rigorous derivation of the quasi-invariant limit for two meaningful choices of the domain of definition of the independent variables. We notice that the domain of definition of the problem plays a crucial role and heavily influences the behavior of the solution. The rigorous proof of the relaxation limit does not need the use of entropy estimates for ensuring compactness.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{zhang_1406,

title = {Failure prediction of magnesium alloys based on improved CDM model},

author = {Kai Zhang and Houssem Badreddine and Naila Hfaiedh and Khemais Saanouni and Jianlin Liu},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0020768321000214?via%3Dihub},

year  = {2021},

date = {2021-01-01},

journal = {International Journal Of Solids And Structures},

volume = {217-218},

pages = {155-177},

abstract = {The aim of this contribution is to improve the behavior and failure prediction accuracy for magnesium alloy sheet forming simulation by using advanced fully coupled Continuum Damage Mechanics (CDM) model. Starting from known fully coupled constitutive equations at large inelastic (plastic or viscoplastic) strains, three aspects are enhanced on the CDM model developed by Saanouni (2012). The first one concerns the accurate description of tension-compression asymmetry in yielding and hardening of magnesium alloys induced by combined slip and twinning deformations. The second concerns introducing the stress state dependence in damage evolution to improve the fracture prediction under various loading paths. The third deals with temperature and strain rate (viscosity) effects for metal forming processes at elevated temperatures. The improved fully coupled constitutive equations were implemented into finite element code ABAQUS/Explicit via user subroutine VUMAT including the specific local integration scheme to compute the state variables at each quadrature point. Various kinds of tensile tests at different temperatures and strain rates are used to determine the material parameters, and the complete identification procedure is given in details. As validation, the improved model is applied to simulate the three-point bending and circular cup deep drawing tests, the predicted results show good agreements with the experimental observations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ouaddi_1582,

title = {Passive piezomagnetic monitoring of structures subjected to in-service cyclic loading: Application to the detection of fatigue crack initiation and propagation},

author = {Achraf Ouaddi and Olivier Hubert and Jader Furtado and Song He},

url = {https://doi.org/10.1063/9.0000195},

year  = {2021},

date = {2021-01-01},

journal = {Aip Advances},

volume = {11},

number = {1},

pages = {015344},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2092,

title = {Multi-scale damage analysis and fatigue behavior of PLA manufactured by fused deposition modeling (FDM)},

author = {Hamidreza Vanaei and Mohammadali Shirinbayani and Saeedeh Vanaei and Joseph Fitoussi and Sofiane Khelladi and Abbas Tcharkhtchi},

url = {https://doi.org/10.1108/RPJ-11-2019-0300},

year  = {2021},

date = {2021-01-01},

journal = {Rapid Prototyping Journal},

volume = {27},

number = {2},

pages = {371-378},

abstract = {Purpose



Fused deposition modeling (FDM) draws particular attention due to its ability to fabricate components directly from a CAD data; however, the mechanical properties of the produced pieces are limited. This paper aims to present the experimental aspect of multi-scale damage analysis and fatigue behavior of polylactic acid (PLA) manufactured by FDM. The main purpose of this paper is to analyze the effect of extruder temperature during the process, loading amplitude, and frequency on fatigue behavior.

Design/methodology/approach



Three specific case studies were analyzed and compared with spool material for understanding the effect of bonding formation: single printed filament, two printed filaments and three printed filaments. Specific experiments of quasi-static tensile tests coupled with microstructure observations are performed to multi-scale damage analysis. A strong variation of fatigue strength as a function of the loading amplitude, frequency and extruder temperature is also presented.



Findings



The obtained experimental results show the first observed damage phenomenon corresponds to the inter-layer bonding of the filament interface at the stress value of 40?MPa. For instance, fatigue lifetime clearly depends on the extruder temperature and the loading frequency. Moreover, when the frequency is 80?Hz, the coupling effect of thermal and mechanical fatigue causes self-heating which decreases the fatigue lifetime.

Originality/value



This paper comprises useful data regarding the mechanical behavior and fatigue lifetime of FDM made PLA specimens. In fact, it evaluates the effect of process parameters (extruder temperature) based on the nature of FDM that is classified as a thermally-driven process.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}