scholarly journals Fast Analytic Simulation for Multi-Laser Heating of Sheet Metal in GPU

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2078 ◽  
Author(s):  
Daniel Mejia-Parra ◽  
Diego Montoya-Zapata ◽  
Ander Arbelaiz ◽  
Aitor Moreno ◽  
Jorge Posada ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Heat Transfer Analysis ◽  
Laser Beams ◽  
Temperature History ◽  
Laser Machining ◽  
Transient Temperature ◽  
Interactive Simulation ◽  
Machining Parameters ◽  
Time Space ◽  
Time Frames

Interactive multi-beam laser machining simulation is crucial in the context of tool path planning and optimization of laser machining parameters. Current simulation approaches for heat transfer analysis (1) rely on numerical Finite Element methods (or any of its variants), non-suitable for interactive applications; and (2) require the multiple laser beams to be completely synchronized in trajectories, parameters and time frames. To overcome this limitation, this manuscript presents an algorithm for interactive simulation of the transient temperature field on the sheet metal. Contrary to standard numerical methods, our algorithm is based on an analytic solution in the frequency domain, allowing arbitrary time/space discretizations without loss of precision and non-monotonic retrieval of the temperature history. In addition, the method allows complete asynchronous laser beams with independent trajectories, parameters and time frames. Our implementation in a GPU device allows simulations at interactive rates even for a large amount of simultaneous laser beams. The presented method is already integrated into an interactive simulation environment for sheet cutting. Ongoing work addresses thermal stress coupling and laser ablation.

Study of Heat Transfer and Freezing Time-Temperature Behavior of Individual Pea Grains by Numerical and Experimental Methods

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Manoj Kumar Sharma ◽  
Anil Kumar Pratihar
Keyword(s):  
Heat Transfer ◽  
Numerical Model ◽  
Transient Heat Conduction ◽  
Experimental Results ◽  
Heat Transfer Analysis ◽  
Temperature History ◽  
Transient Temperature ◽  
Freezing Time ◽  
Air Stream ◽  
Cooling Air

Abstract The present research demonstrates an accurate and simple numerical model for heat transfer analysis within spherical peas when exposed to the cold air stream in a rectangular duct. The transient heat conduction equation (THCE) is solved for spherical shaped pea grains. A detailed numerical and experimental study of freezing time-temperature history for peas has been carried out. Thermal conductivity and volumetric heat capacity are measured experimentally. Temperature-dependent thermophysical properties are used in the transient temperature prediction of peas throughout the phase change process. Crank–Nicolson method has been used for the formulation of the numerical model. The effect of important parameters, viz., the initial temperature of peas, cooling air temperature, and cooling air velocity over pea samples has been studied both numerically as well as experimentally and it has been found that there is good agreement between numerical and experimental results. The correlation coefficient of linear regression, R2, between numerically predicted and experimental results, is found to be 0.987.

Boundary Condition Design to Heat a Moving Object at Uniform Transient Temperature Using Inverse Formulation

2004 ◽  
Vol 126 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Hakan Ertu¨rk ◽  
Ofodike A. Ezekoye ◽  
John R. Howell
Keyword(s):  
Boundary Condition ◽  
Temperature Distribution ◽  
Design Problem ◽  
Manufacturing Industry ◽  
Three Dimensional ◽  
Chemical Deposition ◽  
Iterative Solution ◽  
Conveyor Belt ◽  
Temperature History ◽  
Transient Temperature

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.

Slow scholarship for social work: A praxis of resistance and creativity

2021 ◽  
pp. 147332502199086
Author(s):  
Stéphanie Wahab ◽  
Gita R Mehrotra ◽  
Kelly E Myers
Keyword(s):  
Domestic Violence ◽  
Social Work ◽  
Knowledge Production ◽  
Relational Ontology ◽  
Research Project ◽  
Useful Knowledge ◽  
Time Space ◽  
Rapid Production ◽  
Time Frames

Expediency, efficiency, and rapid production within compressed time frames represent markers for research and scholarship within the neoliberal academe. Scholars who wish to resist these practices of knowledge production have articulated the need for Slow scholarship—a slower pace to make room for thinking, creativity, and useful knowledge. While these calls are important for drawing attention to the costs and problems of the neoliberal academy, many scholars have moved beyond “slow” as being uniquely referencing pace and duration, by calling for the different conceptualizations of time, space, and knowing. Guided by post-structural feminisms, we engaged in a research project that moved at the pace of trust in the integrity of our ideas and relationships. Our case study aimed to better understand the ways macro forces such as neoliberalism, criminalization and professionalization shape domestic violence work. This article discusses our praxis of Slow scholarship by showcasing four specific key markers of Slow scholarship in our research; time reimagined, a relational ontology, moving inside and towards complexity, and embodiment. We discuss how Slow scholarship complicates how we understand constructs of productivity and knowledge production, as well as map the ways Slow scholarship offers a praxis of resistance for generating power from the epistemic margins within social work and the neoliberal academy.

Finite Element Analysis of Incremental Sheet Forming for Metal Sheet

2018 ◽  
Vol 783 ◽  
pp. 148-153
Author(s):  
Muhammad Sajjad ◽  
Jithin Ambarayil Joy ◽  
Dong Won Jung
Keyword(s):  
Mechanical Properties ◽  
Sheet Metal ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Machining Process ◽  
Machining Parameters ◽  
Forming Process ◽  
Element Analysis ◽  
Tool Diameter

Incremental sheet metal forming, is a non-conventional machining process which offers higher formability, flexibility and low cost of production than the traditional conventional forming process. Punch or tool used in this forming process consecutively forces the sheet to deform locally and ultimately gives the target profile. Various machining parameters, such as type of tool, tool path, tool size, feed rate and mechanical properties of sheet metal, like strength co-efficient, strain hardening index and ultimate tensile strength, effects the forming process and the formability of final product. In this research paper, Single Point Incremental Forming was simulated using Dassault system’s Abaqus 6.12-1 and results are obtained. Results of sheet profile and there change in thickness is investigated. For this paper, we simulated the process in abaqus. The tool diameter and rotational speed is find out for the production of parts through incremental forming. The simulation is done for two type of material with different mechanical properties. Various research papers were used to understand the process of incremental forming and its simulation.

THEORETICAL ANALYSES FOR LASER MACHINING MICROCHANNELS AND DEMONSTRATION OF THEIR USES IN MANUFACTURE OF A MICROFLUIDIC OPTICAL SWITCH

2006 ◽  
Vol 13 (06) ◽  
pp. 795-802 ◽  
Author(s):  
DANIEL LIM ◽  
ERNA GONDO SANTOSO ◽  
KIM MING TEH ◽  
STEPHEN WAN ◽  
H. Y. ZHENG
Keyword(s):  
Fluid Flow ◽  
Optical Switch ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Cost Effective ◽  
Laser Machining ◽  
Machining Parameters ◽  
Flow Channels ◽  
Cost Effective Method ◽  
Theoretical Analyses

Silicon has been widely used to fabricate microfluidic devices due to the dominance of silicon microfabrication technologies available. In this paper, theoretical analyses are carried out to suggest suitable laser machining parameters to achieve required channel geometries. Based on the analyses, a low-power CO 2 laser was employed to create microchannels in Acrylic substrate for the use of manufacturing an optical bubble switch. The developed equations are found useful for selecting appropriate machining parameters. The ability to use a low-cost CO 2 laser to fabricate microchannels provides an alternative and cost-effective method for prototyping fluid flow channels, chambers and cavities in microfluidic lab chips.

Transient Thermal Modeling of In-Situ Curing During Tape Winding of Composite Cylinders

2003 ◽  
Vol 125 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Jonghyun Kim ◽  
Tess J. Moon ◽  
John R. Howell
Keyword(s):  
Process Parameters ◽  
Moving Boundary ◽  
Curing Temperature ◽  
Heat Transfer Analysis ◽  
Temperature History ◽  
Maximum Temperature ◽  
Degree Of Cure ◽  
Orthotropic Composites ◽  
Composite Cylinders

Fully-transient, two-dimensional, heat transfer analysis for the simultaneous tape winding and in-situ curing of composite cylinders is presented. During processing, the orthotropic composites are continuously wound onto an isotropic mandrel and cured simultaneously by infrared (IR) heating. To most efficiently and effectively consider the continual accretion of composite, the model is formulated within a Lagrangian reference frame in which the heating source rotates while the coordinate system and composite are stationary. This enables prediction of composite temperature and degree-of-cure history from the first to last layer. Separate heat conduction equations are formulated for both the mandrel and composite cylinder. The composite cylinder’s outer surface is modeled as a moving boundary due to the accumulated layers. Exothermic heat generation due to the epoxy resin’s chemical reaction is included as a function of temperature and degree of cure. Numerical simulations using a control-volume-based finite difference method are run for a common graphite/epoxy (AS4/3501-6) composite. The Lagrangian approach was found to more accurately predict the in-situ curing temperature and degree-of-cure histories than the previously used, quasi-steady-state Eulerian approaches, which underpredict thermal losses. The model and its computational implementation were verified using analytical solutions and actual experiments. During winding, the top layer’s maximum temperature increases with total number of layers wound, demonstrating that a given incoming prepreg tape’s temperature history evolves with time. Moreover, with appropriate mandrel preheating, the inner layers can reach a very high degree of cure by the end of the winding process, revealing that the mandrel’s initial temperature has a significant effect on the composite’s temperature and degree-of-cure history. Substantial increases in the winding speed have little or no effect on the composite’s temperature history, but can significantly reduce the corresponding degree-of-cure. The development of structurally debilitating residual stresses are an important concern in selecting process parameters, such as winding speed and heating power. Taking advantage of the strong correlation between winding speed and IR heat flux, process windows can be used to guide the selection of manufacturing process parameters. These definitively show that there are thermodynamically imposed limits on how fast the cylinders may be wound and radiatively cured.

Evaluation of response characteristics of thin film gauge for conductive heat transfer mode

2020 ◽  
pp. 014233122096066
Author(s):  
Tanweer Alam ◽  
Rakesh Kumar
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Short Duration ◽  
Temperature Data ◽  
Heat Transfer Analysis ◽  
Transient Temperature ◽  
Conductive Heat ◽  
Sensing Element ◽  
Element Analysis

Heat transfer analysis is the one of the most important designing aspects for many engineering systems. The design prospect in the preview of heat transfer focuses on the prediction of heat flux with the help of measured transient temperature data. Thin film gauges are one of the most predominant method for the heat flux prediction especially for short duration transient temperature measurement. Thin film gauges are usually exposed to the heated environment for the measurement purpose. However, there are some prominent research areas like ablation phenomenon met to spacecraft thermal shields during re-entry to the atmosphere, for which direct exposure of the thin film gauge to the heated environment causes the functional and working difficulties associated with the gauge. In the present study, it is aimed to investigate the suitability of thin film gauge for the conduction-based short duration measurement. An experimental set up is fabricated, which is used to supply the heat load to the hand-made thin film gauge using platinum as sensing element and quartz as a substrate. The transient temperature data is recorded during experiment is further compared with the simulated temperature histories obtained through finite element analysis. The heat flux estimation for both the analysis is made using measured transient temperature data by convolute integral of one- dimensional heat conduction equation. The estimated heat flux value for the experimental and numerical result is found to be in excellent agreement.

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