A Computational Efficient Approach to Compute Temperature for Energy Beam Additive Manufacturing

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Chun-Yu Ou ◽  
C. Richard Liu

Abstract Temperature history prediction is essential for a better understanding of the relationship between microstructural change and processing conditions for energy beam additive manufacturing fabricated components. Here, a new efficient approach combining a moving heat source analytical model with a melting and solidification model is presented. An innovative method is proposed to compute the “effective computation zone” as a boundary condition, which can save computation time significantly. Notably, the computational efficiency can improve by 104–105 compared with finite element models. With this range of improvement efficiency, the temperature predicted based on this method is consistent (around 9% of average deviation) with experimental measurements by the thermocouple. This model can be used as a reference to define the boundary condition for further complex numerical analysis with improved accuracy at a reduction of efficiency as desired. In addition, it can be used as a reference to determine processing conditions that would allow the efficient and effective control of the temperature history within a range for a certain microstructure design.

2004 ◽  
Vol 126 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Hakan Ertu¨rk ◽  
Ofodike A. Ezekoye ◽  
John R. Howell

The boundary condition design of a three-dimensional furnace that heats an object moving along a conveyor belt of an assembly line is considered. A furnace of this type can be used by the manufacturing industry for applications such as industrial baking, curing of paint, annealing or manufacturing through chemical deposition. The object that is to be heated moves along the furnace as it is heated following a specified temperature history. The spatial temperature distribution on the object is kept isothermal through the whole process. The temperature distribution of the heaters of the furnace should be changed as the object moves so that the specified temperature history can be satisfied. The design problem is transient where a series of inverse problems are solved. The process furnace considered is in the shape of a rectangular tunnel where the heaters are located on the top and the design object moves along the bottom. The inverse design approach is used for the solution, which is advantageous over a traditional trial-and-error solution where an iterative solution is required for every position as the object moves. The inverse formulation of the design problem is ill-posed and involves a set of Fredholm equations of the first kind. The use of advanced solvers that are able to regularize the resulting system is essential. These include the conjugate gradient method, the truncated singular value decomposition or Tikhonov regularization, rather than an ordinary solver, like Gauss-Seidel or Gauss elimination.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 485
Author(s):  
Xufeng Li ◽  
Jian Lin ◽  
Zhidong Xia ◽  
Yongqiang Zhang ◽  
Hanguang Fu

Wire-arc additive manufacturing (WAAM) has been considered as one of the potential additive-manufacturing technologies to fabricate large components. However, its industrial application is still limited by the existence of stress and distortion. During the process of WAAM, the scanning pattern has an important influence on the temperature field, distortion and final quality of the part. Four kinds of deposition patterns, including sequence, symmetry, in–out and out–in, were designed to deposit H13 steel in this study. An in situ measurement system was set up to record the temperature history and the progress of accumulated distortion of the parts during deposition. An S value was proposed to evaluate the distortion of the substrate. It was shown that the distortion of the part deposited by sequence was significantly larger than those of other parts. The distortion deposited by the out–in pattern decreased by 68.6% compared with sequence. The inherent strain method and strain parameter were introduced to expose the mechanism of distortion reduction caused by pattern variation.


Author(s):  
Shaohua Han ◽  
Zhongzhong Zhang ◽  
Pengxiang Ruan ◽  
Shiwen Cheng ◽  
Dingqi Xue

Additive manufacturing has been proven to be a promising technology for fabricating high-performance dies, molds, and conformal cooling channels. As one of the manufacturing methods, wire and arc additive manufacturing displays unique advantages of low cost and high deposition rate that are better than other high energy beam-based ones. This paper presents a preliminary study of fabricating integrated cooling channels by CMT-based wire and arc additive manufacturing process. The deposition strategies for fabricating circular cross-sectional cooling channels both in conformal and straight-line patterns have been investigated. It included optimizing the welding torch angle, fabricating the enclosed semicircle structure and predicting the collision between the torch and constructed part. The cooling effect test was also conducted on both the conformal cooling channel and straight-line cooling channel. The results affirmed a higher cooling efficiency and better uniform cooling effect of the conformal cooling channel than straight-line cooling channel.


2010 ◽  
Author(s):  
Y. P. Yang ◽  
H. Castner ◽  
N. Kapustka

Two distortion modeling methods, mapping plastic strain and lump-pass modeling, were developed and validated for predicting distortion on large welded structures to reduce the computation time. The mapping plastic-strain method requires two kinds of models, local models and a global model. The local models are analyzed to predict plastic strains and the global model is analyzed by mapping the plastic strains to predict distortions. The lump-pass modeling method includes two kinds of analyses: a thermal analysis and a thermomechanical analysis. The thermal analysis is conducted to predict temperature history. The thermomechanical analysis is performed to predict distortion by inputting the predicted temperature history.


2020 ◽  
Vol 389 (1) ◽  
pp. 1900069 ◽  
Author(s):  
Claudio Tosto ◽  
Alberta Latteri ◽  
Eugenio Pergolizzi ◽  
Davide Giordano ◽  
Giuseppe Abramo ◽  
...  

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2677
Author(s):  
Lukas Hentschel ◽  
Frank Kynast ◽  
Sandra Petersmann ◽  
Clemens Holzer ◽  
Joamin Gonzalez-Gutierrez

The Arburg Plastic Freeforming process (APF) is a unique additive manufacturing material jetting method. In APF, a thermoplastic material is supplied as pellets, melted and selectively deposited as droplets, enabling the use of commercial materials in their original shape instead of filaments. The medical industry could significantly benefit from the use of additive manufacturing for the onsite fabrication of customized medical aids and therapeutic devices in a fast and economical way. In the medical field, the utilized materials need to be certified for such applications and cannot be altered in any way to make them printable, because modifications annul the certification. Therefore, it is necessary to modify the processing conditions rather than the materials for successful printing. In this research, a medical-grade poly(methyl methacrylate) was analyzed. The deposition parameters were kept constant, while the drop aspect ratio, discharge rate, melt temperatures, and build chamber temperature were varied to obtain specimens with different geometrical accuracy. Once satisfactory geometrical accuracy was obtained, tensile properties of specimens printed individually or in batches of five were tested in two different orientations. It was found that parts printed individually with an XY orientation showed the highest tensile properties; however, there is still room for improvement by optimizing the processing conditions to maximize the mechanical strength of printed specimens.


2021 ◽  
Author(s):  
Isciane Caprais ◽  
Pierre Joyot ◽  
Emmanuel Duc ◽  
Simon Deseur

Automated fiber placement processes could be combined with additive manufacturing to produce more functionally complex composite structures with more flexibility. The challenge is to add functions or reinforcements to PEEK/carbon composite parts manufactured by automated fiber placement process, with additive manufacturing by fused filament fabrication. This consists of extruding a molten polymer through a nozzle to create a 3D part. Bonding between polymer filaments is a thermally driven phenomenon and determines the integrity and the final mechanical strength of the printed part. 3d-printing high performance polymers is still very challenging because they involve high thermal gradients during the process. The purpose of this work is to find a process window where the bonding strength is maximized between the composite laminate and the first layer of printed polymer, and inside the printed function as well. Experimental measurements of the temperature profiles at the interface between a composite substrate and 3d-printed PEI under different processing conditions were carried out. The interface was observed using microscopic sections. The methodology for studying the impact of printing parameters on the cohesion and adhesion of printed parts with a composite laminate is described. This work provides insights about the influence of processing conditions on the bond formation between high-performance polymer surfaces. It highlights the importance of controlling the thermal history of the materials all along the process.


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