Experimental validation of finite element modeling for laser powder bed fusion deformation
Experimental validation of finite element modeling for laser powder bed fusion deformation
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DOI：
10.1016/j.addma.2016.08.003
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发表时间：
2016-10-01
影响因子：
11
通讯作者：
Michaleris, Pan
中科院分区：
文献类型：
--
作者：
Dunbar, Alexander J.;Denlinger, Erik R.;Michaleris, Pan
实验测量是模型开发的一个关键组成部分，因为它们需要验证模型预测的准确性。目前，激光粉末床熔凝成形零件的实验数据缺乏。在这里，两个实验构建的圆柱形几何形状，一个使用旋转扫描模式，另一个使用恒定的扫描模式，旨在提供构建后的失真测量。使用坐标测量机进行测量，该坐标测量机在四个单独的位置处提供沿零件高度沿着的变形轮廓。测量结果表明，对于这些圆柱形薄壁结构，使用旋转扫描模式与恒定扫描模式对失真没有明显影响。使用Project Pan有限元建模软件对每个实验构建进行建模。模拟结果显示良好的协议与实验测量的后建立变形，在12%的误差百分比相比，实验测量。使用有限元模型，一个灵活的与刚性基板上的失真轮廓的效果进行了检查。有限元模型进行了验证，对在现场实验测量基板变形。模拟结果被用来研究在构建过程中的应力和变形的演变。通过模型计算的整个零件的内应力用于解释最终零件变形。从这项研究的实验和模拟结果的组合表明，顶层的失真是相对较小的（小于30%），在整个构建过程的持续时间相比，峰值失真，这发生在最近沉积的层下面的几个层。对于这些几何形状，一旦部件被构建到足够的高度，峰值失真幅度不会改变。(C)2016由Elsevier B.V.出版
Experimental measurements are a critical component of model development, as they are needed to validate the accuracy of the model predictions. Currently, there is a deficiency in the availability of experimental data for laser powder bed fusion made parts. Here, two experimental builds of cylindrical geometry, one using a rotating scan pattern and the other using a constant scan pattern, are designed to provide post-build distortion measurements. Measurements are made using a coordinate-measuring machine which provides distortion profiles along the height of the part at four separate locations. Measurements show that for these cylindrical thin wall builds, there is no discernable effect on distortion from using the rotating versus constant scan patterns. Project Pan finite element modeling software is used to model each of the experimental builds. The simulation results show good agreement with experimental measurements of post-build deformation, within a 12% percent error as compared to experimental measurements. Using the FE model, the effect of a flexible versus a rigid substrate on distortion profile is examined. The FE model is validated against in situ experimental measurements of substrate distortion. The simulated results are used to study stress and distortion evolution during the build process. Internal stresses calculated by the model throughout the part are used in explaining the final part distortion. The combination of experimental and simulation results from this study show that the distortion of the top layer is relatively small (less than 30%) throughout the duration of the build process compared to the peak distortion, which occurs several layers below the most recently deposited layer. For these geometries once the part is built to a sufficient height, the peak distortion magnitude does not change. (C) 2016 Published by Elsevier B.V.