Analytical solutions for rapid prediction of transient temperature field in powder-fed laser directed energy deposition based on different heat source models

2021 ◽  
Vol 127 (6) ◽  
Author(s):  
M. Ansari ◽  
M. Khamooshi ◽  
Y. Huang ◽  
E. Toyserkani
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Analytical Solutions ◽  
Energy Deposition ◽  
Transient Temperature ◽  
Directed Energy Deposition ◽  
Transient Temperature Field ◽  
Rapid Prediction ◽  
Source Models ◽  
Directed Energy

scholarly journals Simulating Convective-Radiative Heat Sinks Effect by means of FEA-based Gaussian Heat Sources and Its Approximate Analytical Solutions for Semi-Infinite Body

2021 ◽  
Author(s):  
Ninh The Nguyen ◽  
John H Chujutalli
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
Analytical Solutions ◽  
Radiative Heat ◽  
Source Model ◽  
Heat Sinks ◽  
Transient Temperature ◽  
Measured Temperature ◽  
Heat Source Model ◽  
Transient Temperature Field

Abstract FEA-based Gaussian density heat source models were developed to study the effect of convective and radiative heat sinks on the transient temperature field predicted by the available approximate analytical solution of the purely conduction-based Goldak’s heat source. A new complex 3D Gaussian heat source model, incorporating all three modes of heat transfer, i.e., conduction, convection and radiation, has been developed as an extension of the Goldak heat source. Its approximate transient analytical solutions for this 3-D moving heat source were derived and numerically benchmarked with the available measured temperature & weld pool geometry data by Matlab programming with ~5 to 6 times faster than FEA-based simulation. The new complex 3D Gaussian heat source model and its approximate solution could significantly reduce the computing time in generating the transient temperature field and become an efficient alternative to extensive FEA-based simulations of heating sequences, where virtual optimisation of a melting heat source (i.e. used in welding, heating, cutting or other advanced manufacturing processes) is desirable for characterisation of material behaviour in microstructure evolution, melted pool, microhardness, residual stress and distortions.

Towards Computational Modeling of Temperature Field Evolution in Directed Energy Deposition Processes

2018 ◽  
Author(s):  
Jianyi Li ◽  
Qian Wang ◽  
Panagiotis (Pan) Michaleris
Keyword(s):  
Temperature Field ◽  
Thermal History ◽  
Energy Deposition ◽  
Deposition Process ◽  
Final Part ◽  
Laser Source ◽  
Heat Sources ◽  
Analytical Computation ◽  
Directed Energy Deposition ◽  
Directed Energy

In modeling and simulating thermo-mechanical behavior in a directed energy deposition process, it often needs to compute the temperature field evolved in the deposition process since thermal history in the deposition process would affect part geometry as well as microstructure, material properties, residual stress, and distortion of the final part. This paper presents an analytical computation of temperature field evolved in a directed energy deposition process, using a single-bead wall as an illustrating example. Essentially, the temperature field is computed by superposition of the temperature fields generated by the laser source as well as induced from each of the past beads, where the transient solution to a moving heat source in a semi-infinite body is applied to describe each individual temperature field. For better characterization of cooling effect (temperature contribution from a past bead), a pair of positive and negative virtual heat sources is assigned for each past bead. In addition, mirrored heat sources through a reflexion technique are introduced to define the adiabatic boundaries of the part being built and to account for the substrate thickness. In the end, three depositions of Ti-6AL-4V walls with different geometries and inter-layer dwell times on an Optomec® laser engineered net shaping (LENS) system are used to validate the proposed analytical computation, where predicted temperatures at several locations of the depositions show reasonable agreement with the in situ temperature measurements, with the average prediction error less than 15%. The proposed analytical computation for temperature field in directed energy deposition could be potentially used in model-based feedback control for thermal history in the deposition, which could affect microstructure evolution and other properties of the final part.

scholarly journals Numerical Modeling Design for the Hybrid Additive Manufacturing of Laser Directed Energy Deposition and Shot Peening Forming Fe–Cr–Ni–B–Si Alloy

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4877
Author(s):  
Xiaoyu Zhang ◽  
Dichen Li ◽  
Weijun Zhu
Keyword(s):  
Temperature Field ◽  
Additive Manufacturing ◽  
Tensile Stress ◽  
Compressive Stress ◽  
Shot Peening ◽  
Energy Deposition ◽  
Hybrid Process ◽  
Forming Process ◽  
Directed Energy Deposition ◽  
Directed Energy

Hybrid additive manufacturing is of great significance to make up for the deficiency of the metal forming process; it has been one of the main trends of additive manufacturing in recent years. The hybrid process of laser directed energy deposition (laser DED) and shot peening is a new technology combining the principles of surface strengthening and additive manufacturing, whose difficulty is to reduce the interaction between the two processes. In this paper, a new model with a discrete phase and fluid–solid interaction method is established, and the location of the shot peening point in the hybrid process is optimized. The distributions of the temperature field and powder trajectory were researched and experiments were carried out with the optimized parameters to verify simulation results. It was found that the temperature field and the powder trajectory partly change, and the optimized injection point is located in the stress relaxation zone of the material. The densities and surface residual stresses of samples were improved, and the density increased by 8.83%. The surface stress changed from tensile stress to compressive stress, and the introduced compressive stress by shot peening was 2.26 times the tensile stress produced by laser directed energy deposition.

scholarly journals An Analytical Computation of Temperature Field Evolved in Directed Energy Deposition

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Jianyi Li ◽  
Qian Wang ◽  
Panagiotis (Pan) Michaleris
Keyword(s):  
Temperature Field ◽  
Energy Deposition ◽  
Deposition Process ◽  
Laser Source ◽  
Substrate Thickness ◽  
Heat Sources ◽  
Infinite Body ◽  
Analytical Computation ◽  
Directed Energy Deposition ◽  
Directed Energy

This paper presents an analytical computation of temperature field evolved in a directed energy deposition process, using single-bead walls as illustrating examples. Essentially, the temperature field evolution during the deposition of a wall is computed by super-position of the temperature field generated by the laser source depositing the current bead and that induced from each of the past beads (layers). First, the transient solution to a point heat source in a semi-infinite body is applied to describe each individual temperature field. Then, to better describe temperature contribution from a past bead, a pair of virtual heat sources with positive and negative powers is assigned for each past bead to compute the temperature field under cooling. In addition, mirrored heat sources through a reflexion technique are introduced to define adiabatic boundaries of the part and to account for substrate thickness. In the end, three depositions of Ti-6AL-4V walls with different geometries and interlayer dwell times on an Optomec® laser engineering net shaping (LENS) system are used to validate the proposed analytical computation, where predicted temperatures at several locations of the substrate show reasonable agreement with the in situ temperature measurements with prediction error rate ranging from 12% to 27%. Furthermore, temperature distributions predicted by the proposed model are compared to finite element simulations. The proposed analytical computation for temperature field could be potentially used in model-based feedback control for thermal history in the deposition, which could affect microstructure evolution and other properties of the final part.

scholarly journals A semi-analytical solution of three-dimensional transient temperature field for a uniform plate subjected to Gaussian-distribution laser heat source

2019 ◽  
pp. 268-268
Author(s):  
Xiaogui Wang ◽  
Yili Xiao ◽  
Ninghua Gao ◽  
Lihua Liang ◽  
Congda Lu ◽  
...  
Keyword(s):  
Temperature Field ◽  
Analytical Solution ◽  
Heat Source ◽  
Gaussian Distribution ◽  
Three Dimensional ◽  
Source Distribution ◽  
Transient Temperature ◽  
Laser Heat ◽  
Transient Temperature Field ◽  
Laser Heat Source

One three-dimensional transient temperature field model for a thin uniform plate caused by a moving laser heat source is described in present study. The heat source model with a power density in Gaussian-distribution form is considered when a finite-thin uniform plate is heated. By using the separate variable method (SVM) and the Newton Cotes method (NCM), a semi- analytical solution of three-dimensional heat conduction equation in the finite field is obtained. Numerical results show that the effect of laser heat source distribution, laser moving speed as well as aspect ratio of the thin uniform plate have great influence on the three-dimensional distribution of the temperature field.

Research on Transient Temperature Field Modeling and Simulation of Flat End Mill for High Speed Milling

2013 ◽  
Vol 415 ◽  
pp. 677-680
Author(s):  
Guang Yu Tan ◽  
Da Peng Li ◽  
Dong Chen ◽  
Zhen Yu Wang ◽  
Guang Hui Li
Keyword(s):  
Temperature Field ◽  
Heat Source ◽  
High Speed ◽  
Field Model ◽  
Depth Of Cut ◽  
Transient Temperature ◽  
End Mill ◽  
Line Heat Source ◽  
Transient Temperature Field ◽  
Temperature Field Model

In order to reveal the breakage mechanism of flat end mill under periodic thermal shock, transient temperature field model of chisel edge were established by heat source method, transient temperature field model of side edge were established along the sliced differential elements from the bottom of the flute toward the final axial depth of cut by means of line heat source. The simulation results show that transient temperature field prediction model can be used for prediction transient temperature field in high speeding.

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