Hamidreza Vanaei

@article{vanaei_2061,

title = {Numerical-Experimental Analysis toward the Strain Rate Sensitivity of 3D-Printed Nylon Reinforced by Short Carbon Fiber},

author = {Hamidreza Vanaei and Anouar El Magri and Mohammadali Rastak and Saeedeh Vanaei and Sébastien Vaudreuil and Abbas Tcharkhtchi},

url = {https://doi.org/10.3390/ma15248722},

year  = {2022},

date = {2022-12-01},

journal = {Materials},

volume = {15},

number = {24},

pages = {8722},

abstract = {Despite the application of the Additive Manufacturing process and the ability of parts' construction directly from a 3D model, particular attention should be taken into account to improve their mechanical characteristics. In this paper, we present the effect of individual process variables and the strain-rate sensitivity of Onyx (Nylon mixed with chopped carbon fiber) manufactured by Fused Filament Fabrication (FFF), using both experimental and simulation manners. The main objective of this paper is to present the effect of the selected printing parameters (print speed and platform temperature) and the sensitivity of the 3D-printed specimen to the strain rate during tensile behavior. A strong variation of tensile behavior for each set of conditions has been observed during the quasi-static tensile test. The variation of 40 °C in the platform temperature results in a 10% and 11% increase in Young's modulus and tensile strength, and 8% decrease in the failure strain, respectively. The variation of 20 mm·s?1 in print speed results in a 14% increase in the tensile strength and 11% decrease in the failure strain. The individual effect of process variables is inevitable and affects the mechanical behavior of the 3D-printed composite, as observed from the SEM micrographs (ductile to brittle fracture). The best condition according to their tensile behavior was chosen to investigate the strain rate sensitivity of the printed specimens both experimentally and using Finite Element (FE) simulations. As observed, the strain rate clearly affects the failure mechanism and the predicted behavior using the FE simulation. Increase in the elongation speed from 1 mm·min?1 to 100 mm·min?1, results in a considerable increase in Young's modulus. SEM micrographs demonstrated that although the mechanical behavior of the material varied by increasing the strain rate, the failure mechanism altered from ductile to brittle failure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vaudreuil_2062,

title = {Effects of Power and Laser Speed on the Mechanical Properties of AlSi7Mg0.6 Manufactured by Laser Powder Bed Fusion},

author = {Sébastien Vaudreuil and Salah Eddine Bencaid and Hamidreza Vanaei and Anouar El Magri},

url = {https://doi.org/10.3390/ma15238640},

year  = {2022},

date = {2022-12-01},

journal = {Materials},

volume = {15},

number = {23},

pages = {8640},

abstract = {The AlSi7Mg0.6 alloy, with its good tolerance against strain, is used in laser powder bed fusion (LPBF) to produce parts with complex geometries for aerospace engineering. Production of parts with good mechanical strength requires, however, the optimization of laser parameters. This study thus evaluated the influence of scanning speed, laser power, and strategy on several mechanical properties (tensile/resilience/hardness) to identify an optimal processing region. Results have shown the profound influence of laser power and scanning speed on mechanical properties, with a limited influence from the laser strategy. Tensile strength values ranging from 122 to 394 MPa were obtained, while Young's Modulus varied from 17 to 29 GPa, and the elongation at break ranged from 2.1 to 9.8%. Surface plots of each property against laser power and speed revealed a region of higher mechanical properties. This region is found when using 50 µm thick layers for energy densities between 25 and 35 J/mm3. Operating at higher values of energy density yielded sub-optimal properties, while a lower energy density resulted in poor performances. Results have shown that any optimization strategy must not only account for the volumic energy density value, but also for laser power itself when thick layers are used for fabrication. This was shown through parts exhibiting reduced mechanical performances that were produced within the optimal energy density range, but at low laser power. By combining mid-speed and power within the optimal region, parts with good microstructure and limited defects such as balling, keyhole pores, and hot cracking will be produced. Heat-treating AlSi7Mg0.6 parts to T6 temper negatively affected mechanical performances. Adapted tempering conditions are thus required if improvements are sought through tempering.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ouassil_2046,

title = {Investigating the effect of printing conditions and annealing on the porosity and tensile behavior of 3D-printed polyetherimide material in Z-direction},

author = {Salah-Eddine Ouassil Ouassil and Anouar El Magri and Hamidreza Vanaei and Sébastien Vaudreuil},

url = {https://doi.org/10.1002/app.53353},

year  = {2022},

date = {2022-11-01},

journal = {Journal Of Applied Polymer Science},

volume = {Not assigned yet},

number = {e53353},

pages = {53353},

abstract = {Fused filament fabrication process presents drawbacks in mechanical properties observed when printing in the build direction (Z-direction). Such anisotropic properties will affect the part's performances and have to be minimized during fabrication. This study aims to evaluate the effects of nozzle temperature, printing speed and specimen state (annealed or as-printed) on porosity percentage and tensile properties for 3D printed polyetherimide (PEI) (ULTEM 1010) parts in Z-direction. The results demonstrated that print speed is the most influential process parameter that should be adjusted in consideration with the other printing parameters. The specimens' state did not reveal a noticeable influence, as the amorphous nature of PEI is considered less receptive to annealing. The optimization method to achieve the best results yielded values of 360 °C and 30 mm/s as printing conditions, followed by heat treatment. This was confirmed by porosity measurements, tensile testing, and scanning electron microscopy observations. The best performances of PEI material were 3425.5 MPa, 102 MPa, and 4.30% for Young's modulus, tensile strength, and elongation at break, respectively.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_1962,

title = {Roadmap: Numerical-Experimental Investigation and Optimization of 3D-Printed Parts Using Response Surface Methodology},

author = {Hamidreza Vanaei and Sofiane Khelladi and Abbas Tcharkhtchi},

url = {https://www.mdpi.com/1996-1944/15/20/7193},

year  = {2022},

date = {2022-10-01},

journal = {Materials},

volume = {15},

number = {20},

pages = {7193},

abstract = {Several process variables can be taken into account to optimize the fused filament fabrication (FFF) process, a promising additive manufacturing technique. To take into account the most important variables, a numerical-experimental roadmap toward the optimization of the FFF process, by taking into account some physico-chemical and mechanical characteristics, has been proposed to implement the findings through the thermal behavior of materials. A response surface methodology (RSM) was used to consider the effect of liquefier temperature, platform temperature, and print speed. RSM gave a confidence domain with a high degree of crystallinity, Young's modulus, maximum tensile stress, and elongation at break. Applying the corresponding data from the extracted zone of optimization to the previously developed code showed that the interaction of parameters plays a vital role in the rheological characteristics, such as temperature profile of filaments during deposition. Favorable adhesion could be achieved through the deposited layers in the FFF process. The obtained findings nurture motivations for working on the challenges and bring us one step closer to the optimization objectives in the FFF process to solve the industrial challenges.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{el_magri_1892,

title = {Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering},

author = {Anouar El Magri and Salah Eddine Bencaid and Hamidreza Vanaei and Sébastien Vaudreuil},

url = {https://www.mdpi.com/2073-4360/14/17/3674},

year  = {2022},

date = {2022-09-01},

journal = {Polymers},

volume = {14},

number = {17},

pages = {3674},

abstract = {Poly(dodecano-12-lactam) (commercially known as polyamide ?PA12?) is one of the most resourceful materials used in the selective laser sintering (SLS) process due to its chemical and physical properties. The present work examined the influence of two SLS parameters, namely, laser power and hatch orientation, on the tensile, structural, thermal, and morphological properties of the fabricated PA12 parts. The main objective was to evaluate the suitable laser power and hatching orientation with respect to obtaining better final properties. PA12 powders and SLS-printed parts were assessed through their particle size distributions, X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), a scanning electron microscope (SEM), and their tensile properties. The results showed that the significant impact of the laser power while hatching is almost unnoticeable when using a high laser power. A more significant condition of the mechanical properties is the uniformity of the powder bed temperature. Optimum factor levels were achieved at 95% laser power and parallel/perpendicular hatching. Parts produced with the optimized SLS parameters were then subjected to an annealing treatment to induce a relaxation of the residual stress and to enhance the crystallinity. The results showed that annealing the SLS parts at 170 °C for 6 h significantly improved the thermal, structural, and tensile properties of 3D-printed PA12 parts},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{el_magri_1958,

title = {Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering},

author = {Anouar El Magri and Hamidreza Vanaei and Salah Eddine Bencaid and Sébastien Vaudreuil},

url = {https://doi.org/10.3390/polym14173674},

year  = {2022},

date = {2022-09-01},

journal = {Polymers},

volume = {14},

number = {17},

pages = {3674},

abstract = {Poly(dodecano-12-lactam) (commercially known as polyamide ?PA12?) is one of the most resourceful materials used in the selective laser sintering (SLS) process due to its chemical and physical properties. The present work examined the influence of two SLS parameters, namely, laser power and hatch orientation, on the tensile, structural, thermal, and morphological properties of the fabricated PA12 parts. The main objective was to evaluate the suitable laser power and hatching orientation with respect to obtaining better final properties. PA12 powders and SLS-printed parts were assessed through their particle size distributions, X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), a scanning electron microscope (SEM), and their tensile properties. The results showed that the significant impact of the laser power while hatching is almost unnoticeable when using a high laser power. A more significant condition of the mechanical properties is the uniformity of the powder bed temperature. Optimum factor levels were achieved at 95% laser power and parallel/perpendicular hatching. Parts produced with the optimized SLS parameters were then subjected to an annealing treatment to induce a relaxation of the residual stress and to enhance the crystallinity. The results showed that annealing the SLS parts at 170 °C for 6 h significantly improved the thermal, structural, and tensile properties of 3D-printed PA12 parts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{m._himeur_2099,

title = {Towards an Accurate Aerodynamic Performance Analysis Methodology of Cross-Flow Fans},

author = {Rania M. Himeur and Sofiane Khelladi and Mohamed Abdessamed AIT CHIKH and Hamidreza Vanaei and Idir Belaidi and Farid Bakir},

url = {https://doi.org/10.3390/en15145134},

year  = {2022},

date = {2022-07-01},

journal = {Energies},

volume = {15},

number = {14},

pages = {5134},

abstract = {Cross-flow fans (CFFs) have become increasingly popular in recent years. This is due to their use in several domains such as air conditioning and aircraft propulsion. They also show their utility in the ventilation system of hybrid electric cars. Their high efficiency and performance significantly rely on the design parameters. Up to now, there is no general approach that predicts the CFFs' performance. This work describes a new methodology that helps deduce the performance of CFFs in turbomachinery, using both analytical modeling and experimental data. Two different loss models are detailed and compared to determine the performance-pressure curves of this type of fan. The efficiency evaluation is achieved by realizing a multidisciplinary study, computational fluid dynamics (CFD) simulations, and an optimization algorithm combined to explore the internal flow field and obtain additional information about the eccentric vortex, to finally obtain the ultimate formulation of the Eck/Laing CFF efficiency, which is validated by the experimental results with good agreement. This approach can be an efficient tool to speed up the cross-flow fans' design cycle and to predict their global performance.},

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{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{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{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{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}

}

@article{vanaei_1959,

title = {An Overview on Materials and Techniques in 3D Bioprinting Toward Biomedical Application},

author = {Saeedeh Vanaei and Mohammad Salemizadeh Parizi and Shohreh Vanaei and Fatemeh Salemizadehparizi and Hamidreza Vanaei},

url = {https://doi.org/10.1016/j.engreg.2020.12.001},

year  = {2020},

date = {2020-12-01},

journal = {Engineered Regeneration},

volume = {2},

pages = {1-18},

abstract = {Three-dimensional (3D) bioprinting, an additive manufacturing based technique of biomaterials fabrication, is an innovative and auspicious strategy in medical and pharmaceutical fields. The ability of producing regenerative tissues and organs has made this technology a pioneer to the creation of artificial multi-cellular tissues/organs. A broad variety of biomaterials is currently being utilized in 3D bioprinting as well as multiple techniques employed by researchers. In this review, we demonstrate the most common and novel biomaterials in 3D bioprinting technology further with introducing the related techniques that are commonly taking into account by researchers. In addition, an attempt has been accomplished to hand over the most relevant application of 3D bioprinting techniques such as tissue regeneration, cancer investigations, etc. by presenting the most important works. The main aim of this review paper is to emphasis on strengths and limitations of existence biomaterials and 3D bioprinting techniques in order to carry out a comparison through them.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2096,

title = {A comparative in-process monitoring of temperature profile in fused filament fabrication},

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

url = {https://doi.org/10.1002/pen.25555},

year  = {2020},

date = {2020-10-01},

journal = {Polymer Engineering And Science},

volume = {61},

number = {1},

pages = {68-76},

abstract = {Fused filament fabrication (FFF), an additive manufacturing technique, is used to produce prototypes and a gradually more important processing route to get final products. Due to the layer-by-layer deposition mechanism involved, bonding between adjacent layers is controlled by the thermal energy of the material being printed. Thus, it is strongly in conjunction with the temperature development of the filaments during the deposition sequence. This study gives out an in-process set-up enabling to record temperature profile of two adjacent filaments or a sequence of deposition in various locations during FFF process. The main characteristic of the presented procedure is the possibility of obtaining a global temperature profile resulted from an IR-camera; parallel to those recorded using a K-type thermocouple. Needless to say that a K-type thermocouple accurately records the local temperature at the interface of adjacent filaments. Conversely, an IR-camera signifies the temperature profile on the captured surface. The obtained results showed that there is a remarkable difference between the cooling rate and re-heating peaks. The primary outcome of this study is the consideration of results accuracy and the possibility of working on optimization of the obtained temperature profile. Altogether it helps optimize inter-layer strength while assessing the temperature evolution.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2091,

title = {Experimental study of PLA thermal behavior during fused filament fabrication},

author = {Hamidreza Vanaei and Mohammadali Shirinbayani and Sidonie Fernandes Costa and Fernando Moura Duarte and José António Covas and Deligant Michael and Sofiane Khelladi and Abbas Tcharkhtchi},

url = {https://doi.org/10.1002/app.49747},

year  = {2020},

date = {2020-08-01},

journal = {Journal Of Applied Polymer Science},

volume = {138},

number = {4},

pages = {49747},

abstract = {Fused filament fabrication (FFF) is an additive manufacturing technique that is used to produce prototypes and a gradually more important processing route to obtain final products. Due to the layer-by-layer deposition mechanism involved, bonding between adjacent layers is controlled by the thermal energy of the material being printed, which strongly depends on the temperature development of the filaments during the deposition sequence. This study reports experimental measurements of filament temperature during deposition. These temperature profiles were compared to the predictions made by a previously developed model. The two sets of data showed good agreement, particularly concerning the occurrence of reheating peaks when new filaments are deposited onto previously deposited ones. The developed experimental technique is shown to demonstrate its sensitivity to changing operating conditions, namely platform temperature and deposition velocity. The data generated can be valuable to predict more accurately the bond quality achieved in FFF parts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2090,

title = {Toward the understanding of temperature effect on bonding strength, dimensions and geometry of 3D-printed parts},

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

url = {https://doi.org/10.1007/s10853-020-05057-9},

year  = {2020},

date = {2020-07-01},

journal = {Journal Of Materials Science},

volume = {55},

number = {0},

pages = {14677-14689},

abstract = {Fused filament fabrication (FFF), which is an additive manufacturing technique, opens alternative possibilities for complex geometries fabrication. However, its use in functional products is limited due to anisotropic strength issues. Indeed, the strength of FFF fabricated parts across successive layers in the build direction (Z direction) can be significantly lower than the strength in X-Y directions. This strength weakness has been attributed to poor bonding between printed layers. This bonding depends on the temperature of the current layer being deposited?at melting temperature (Tm)?and the temperature of the previously deposited layer. It is assumed that depositing a layer at Tm on a layer at temperature around crystallization temperature (Tc) would enable higher material crystallinity and thus better bonding between previous and present layers. On the contrary, if the previous layer temperature is below Tc, material crystallinity will be low and bonding strength weak. This paper aims at studying the significant effect of temperature difference (?T) between previous and current deposited layers temperatures on (1) inter-layers bonding strength improvement and (2) part dimensions, geometry and structure stability. A 23% increase in the inter-layers bonding strength for previous layer temperature slightly higher than Tc reported here confirms the above assumption and offers a first solution toward the increase in inter-layers bonding strength in FFF.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2087,

title = {Influence of process parameters on thermal and mechanical properties of polylactic acid fabricated by fused filament fabrication},

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

url = {https://doi.org/10.1002/pen.25419},

year  = {2020},

date = {2020-05-01},

journal = {Polymer Engineering And Science},

volume = {60},

number = {8},

pages = {1822-1831},

abstract = {Fused filament fabrication is considered one of the most used processes in additive manufacturing rapid prototypes out of polymeric material. Poor strength of the deposited layers is still one of the main critical problems in this process, which affects the mechanical properties of the final parts. To improve the mechanical strength, investigation into various process parameters must be considered. In this article, the influence of different process parameters has been experimentally investigated by means of physicochemical and mechanical characterizations. Special attention was given to the thermal aspect. In that respect, the in situ measurement of temperature profile during deposition indicated that several parameters affect the cooling rate of material and consequently have an influence on the final parts. It was found that the influence of increasing the extruder temperature is more significant in comparison with other process parameters.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2086,

title = {A review on pipeline corrosion, in-line inspection (ILI), and corrosion growth rate models},

author = {Hamidreza Vanaei and Eslami Abdoulmajid and Egbewande Afoulabi},

url = {https://doi.org/10.1016/j.ijpvp.2016.11.007},

year  = {2016},

date = {2016-11-01},

journal = {International Journal Of Pressure Vessels And Piping},

volume = {149},

number = {0},

pages = {43-54},

abstract = {Pipelines are the very important energy transmission systems. Over time, pipelines can corrode. While corrosion could be detected by in-line inspection (ILI) tools, corrosion growth rate prediction in pipelines is usually done through corrosion rate models. For pipeline integrity management and planning selecting the proper corrosion ILI tool and also corrosion growth rate model is important and can lead to significant savings and safer pipe operation. In this paper common forms of pipeline corrosion, state of the art ILI tools, and also corrosion growth rate models are reviewed. The common forms of pipeline corrosion introduced in this paper are Uniform/General Corrosion, Pitting Corrosion, Cavitation and Erosion Corrosion, Stray Current Corrosion, Micro-Bacterial Influenced Corrosion (MIC). The ILI corrosion detection tools assessed in this study are Magnetic Flux Leakage (MFL), Circumferential MFL, Tri-axial MFL, and Ultrasonic Wall Measurement (UT). The corrosion growth rate models considered in this study are single-value corrosion rate model, linear corrosion growth rate model, non-linear corrosion growth rate model, Monte-Carlo method, Markov model, TD-GEVD, TI-GEVD model, Gamma Process, and BMWD model. Strengths and limitations of ILI detection tools, and also corrosion predictive models with some practical examples are discussed. This paper could be useful for those whom are supporting pipeline integrity management and planning.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}