scholarly journals In-Process Monitoring of Temperature Evolution during Fused Filament Fabrication: A Journey from Numerical to Experimental Approaches

Thermo ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 332-360
Author(s):  
Hamid Reza Vanaei ◽  
Mohammadali Shirinbayan ◽  
Michael Deligant ◽  
Sofiane Khelladi ◽  
Abbas Tcharkhtchi
Keyword(s):  
Heat Transfer ◽  
Temperature Profile ◽  
Process Monitoring ◽  
Alternative Possibilities ◽  
Temperature History ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Layer Deposition ◽  
Thermally Driven ◽  
History Of

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.

Predicting strength of additively manufactured thermoplastic polymer parts produced using material extrusion

2018 ◽  
Vol 24 (2) ◽  
pp. 321-332 ◽  
Author(s):  
Joseph Bartolai ◽  
Timothy W. Simpson ◽  
Renxuan Xie
Keyword(s):  
Infrared Imaging ◽  
Acrylonitrile Butadiene Styrene ◽  
Temperature History ◽  
Interface Temperature ◽  
Fused Filament Fabrication ◽  
Content Type ◽  
Material Extrusion ◽  
Rheological Data ◽  
History Of ◽  
Butadiene Styrene

Purpose The weakest point in additively manufactured polymer parts produced by material extrusion additive manufacturing (MEAM) is the interface between adjacent layers and deposition toolpaths or “roads”. This study aims to predict the mechanical strength of parts by utilizing a novel analytical approach. Strength predictions are made using the temperature history of these interfaces, polymer rheological data, and polymer weld theory. Design/methodology/approach The approach is validated using experimental data for two common 3D-printed polymers: polycarbonate (PC) and acrylonitrile butadiene styrene (ABS). Interface temperature history data are collected in situ using infrared imaging. Rheological data of the polycarbonate and acrylonitrile butadiene styrene used to fabricate the fused filament fabrication parts in this study have been determined experimentally. Findings The strength of the interfaces has been predicted, to within 10% of experimental strength, using polymer weld theory from the literature adapted to the specific properties of the polycarbonate and acrylonitrile butadiene styrene feedstock used in this study. Originality/value This paper introduces a novel approach for predicting the strength of parts produced by MEAM based on the strength of interfaces using polymer weld theory, polymer rheology, temperature history of the interface and the forces applied to the interface. Unlike methods that require experimental strength data as a prediction input, the proposed approach is material and build orientation agnostic once fundamental parameters related to material composition have been determined.

The Emissivity and Absorptivity of Parachute Fabrics

1959 ◽  
Vol 81 (3) ◽  
pp. 195-200 ◽  
Author(s):  
J. P. Hartnett ◽  
E. R. G. Eckert ◽  
R. Birkebak
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Wave Length ◽  
Radiant Energy ◽  
Temperature History ◽  
Appreciable Amount ◽  
Sufficient Information ◽  
Radiation Properties ◽  
History Of ◽  
Materials Used

The use of parachutes for recovery of information and equipment from high-speed vehicles has directed attention to the heating problem which in some instances may be so severe as to cause destruction of the parachute. Consequently, the parachute engineer requires sufficient information on the heat-transfer characteristics of geometries resembling those of parachutes and on the heat-transfer properties of the materials used to allow a calculation of the temperature history of a descending parachute. In particular, the radiation properties of the parachute materials must be known since the parachute is receiving radiant energy from the sun and loses energy by radiation to the surroundings. The measurement of radiation properties for such parachute materials is more complicated than for solid surfaces since an appreciable amount of energy is transmitted by such fabrics. It is the purpose of this paper to describe the equipment which was used to measure the absorptivity for solar radiation and the long-wave-length emissivity for such parachute materials and to report these data for a number of important parachute materials.

Numerical Simulation and Experiment Research on Temperature Field of Steel Slab in Walking Beam Furnace

2011 ◽  
Vol 704-705 ◽  
pp. 412-418 ◽  
Author(s):  
Chao Chen ◽  
Cui Jiao Ding ◽  
De Gang Ouyang ◽  
Zhan Zeng Liu ◽  
Zhong Hua Song ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Temperature Fields ◽  
Temperature History ◽  
Experiment Research ◽  
Steel Slab ◽  
History Of ◽  
Simulation And Experiment ◽  
Heating Up

This paper presents a study of the temperature fields of steel slab in a walking beam furnace. To simulate the temperature distribution in the slab of heating-up process in heating furnace, a two-dimensional mathematical model was developed. The heat transfer in the furnace was very complex, so the model was developed on the assumptions that the temperature of each section of the furnace was unchangeable, the slab moved in the furnace in even velocity, the heat transfer between the slab and the walking beam was out of consideration, the longitudinal heat conduction of the slab and the effect of the scale on the heat conduction were neglected. The equations were calculated by the finite difference method. A black box experiment research was carried out to measure the temperature history of the slab as it passed through the furnace. The comparison of the calculated results with the measured results showed that the model worked well for simulating the temperature distribution of the slab in walking beam furnace. With this developed model, the optimizing of hot rolling and heating processes of steel slab can be investigated in the future.

A comparative in‐process monitoring of temperature profile in fused filament fabrication

2020 ◽  
Author(s):  
H.R. Vanaei ◽  
M. Deligant ◽  
M. Shirinbayan ◽  
K. Raissi ◽  
J. Fitoussi ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Process Monitoring ◽  
Fused Filament Fabrication

An Inverse Analysis Method for Estimation of Heat Flux and Temperature-Dependence of Heat Transfer Coefficient

2011 ◽  
Author(s):  
Shiro Kubo ◽  
Seiji Ioka
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Inverse Method ◽  
Thermal Stresses ◽  
Temperature History ◽  
Inner Surface ◽  
History Of ◽  
Transient Thermal ◽  
The Relationship ◽  
Inverse Analysis Method

Transient thermal stresses develop in pipes during start-up and shut-down. In previous papers the present authors [1–4] proposed an inverse method for determining the optimum thermal inlet liquid temperature history which reduced the maximum transient thermal stress in pipes. The papers considered multiphysics including heat conduction, heat transfer, and elastic deformation. The inverse method used the relationship between inner surface temperature history, transient temperature distribution and transient thermal stresses. The coefficient of heat transfer plays an important role in the evaluation of thermal stress. In this study an inverse method was developed for estimating heat flux and temperature-dependence of the coefficient of heat transfer from the history of the outer surface temperature and the liquid temperature. The method used the relationship between the outer surface temperature and the inner surface temperature. For the regularization of solution the function expansion method was applied in expressing the history of flux on the inner surface. Numerical simulations demonstrated the usefulness of the proposed inverse analysis method. By examining the effect of measurement errors of temperature on the estimation, the robustness of the method was shown.

scholarly journals The 3D Printing of Freestanding PLLA Thin Layers and Improving First Layer Consistency through the Introduction of Sacrificial PVA

2021 ◽  
Vol 11 (14) ◽  
pp. 6320
Author(s):  
David M. Roper ◽  
Kyung-Ah Kwon ◽  
Serena M. Best ◽  
Ruth E. Cameron
Keyword(s):  
Thin Layers ◽  
Patient Specific ◽  
Thickness Variation ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Thin Structures ◽  
Complex Patient ◽  
Layer Deposition ◽  
Layer Structures ◽  
3D Printed

Fused filament fabrication (FFF) is an inexpensive way of producing objects through a programmed layer-by-layer deposition. For multi-layer, macro-scaled prints, acceptable printing is achieved provided, amongst other factors, first layer adhesion is sufficient to fix a part to the surface during printing. However, in the deposition of structures with a single or few layers, first layer consistency is significantly more important and is an issue that has been previously overlooked. As layer-to-bed adhesion is prioritised in first layer printing, thin layer structures are difficult to remove without damage. The deposition of controllable thin structures has potential in tissue engineering through the use of bioactive filaments and incorporation of microfeatures into complex, patient-specific scaffolds. This paper presents techniques to progress the deposition of thin, reproducible structures. The linear thickness variation of 3D-printed single PVA and PLLA layers is presented as a function of extrusion factor and the programmed vertical distance moved by the nozzle between layers (the layer separation). A sacrificial PVA layer is shown to significantly improve first layer consistency, reducing the onus on fine printer calibration in the deposition of single layers. In this way, the linear variation in printed single PLLA layers with bed deviation is drastically reduced. Further, this technique is used to demonstrate the printing of freestanding thin layers of ~25 µm in thickness.

scholarly journals NUMERICAL SIMULATION OF TEMPERATURE DISTRIBUTION ON METAL CASTING IN VERTICAL SOLIDIFICATION

2018 ◽  
Vol 17 (2) ◽  
pp. 80
Author(s):  
G. M. Stieven ◽  
D. R. Soares ◽  
E. P. Oliveira ◽  
E. F. Lins
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Technique ◽  
Heat Transfer Process ◽  
Temperature History ◽  
Energy Liberation ◽  
Vertical Solidification ◽  
History Of ◽  
Two Phases ◽  
Good Agreement

The metals and alloys solidification can be defined as a transient heat transfer process. A liquid/solid transformation is followed by thermal energy liberation, with a movable boundary separating two phases with different thermophysical properties. The solidification is of great interest to mechanical and chemical engineers. It is a non-linear transient phenomenon, where heat transfer between the casting and the mold plays a important role. This paper aims to propose a study of heat flow from the casting to the mold using a numerical technique to compute the temperature history of all points inside the casting. The cooling process consists of water-cooled mold with heat being extracted only from the bottom, resulting in unidirectional vertical solidification. The ANSYS software was used to obtain the temperature distribution in the casting. Good agreement was obtained when the simulation results were compared with the experimental data.

Temperature Variation History Prediction of Fully-Closed Adhesive Joint in Curing Process

2010 ◽  
Vol 44-47 ◽  
pp. 394-399
Author(s):  
Chu Chen ◽  
Zhi Guo Lu ◽  
Jian Ping Lin
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Adhesive Joint ◽  
Temperature History ◽  
Curing Process ◽  
Transfer Coefficients ◽  
Temperature Prediction ◽  
Heat Transfer Coefficients ◽  
Heat Transfer Theory ◽  
History Of

To describe the heat transfer of fully-closed adhesive joint in curing process, adhesive joint, enclosure for closing joints and its inner air are simplified as a multi-lumped-heat-capacity system neglecting the heat from adhesive chemical reaction. Based on heat transfer theory, a temperature prediction model of fully-closed joint was proposed. Combining experimental temperature history of the joint with finite difference method, the combined heat transfer coefficients of adhesive under different curing temperatures were obtained according to Newton's heat transfer formula. And the model was validated by the experiments. The results revealed that the model can be used to predict the temperature of fully-closed adhesive joint in curing process.

DETERMINE THE DISTRIBUTION AND HISTORY OF WORKPIECE TEMPERATURE FOR DRY MILLING

2008 ◽  
Vol 07 (02) ◽  
pp. 279-282
Author(s):  
WEN JUN DENG ◽  
WEI XIA
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Finite Element Model ◽  
Temperature Profile ◽  
Element Model ◽  
Milling Process ◽  
Machining Process ◽  
Temperature History ◽  
Dry Milling ◽  
History Of

A 2D finite element model of dry milling process is developed to determine the temperature distribution and temperature history of workpiece. The flow stress of workpiece is taken as a function of strain, strain rate and temperature in order to reflect realistic behavior in machining process. Temperature-dependent material properties are also employed in the analysis. From the simulation, a lot of information on dry milling process can be obtained; cutting force, cutting temperature, chip shape, temperature distribution, etc. The temperature history of the machined layer can be reported by conducting a point tracking. The predicted temperature profile at conventional cutting speeds and high speed machining are obtained. The finite element model appears to be perfectly representative of dry milling process and can be used to predict instantaneous temperature profile and temperature history into the depth of the workpiece.

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