Thermomechanical Modeling of Additive Manufacturing Large Parts
Thermomechanical Modeling of Additive Manufacturing Large Parts
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DOI：
10.1115/1.4028669
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发表时间：
2014-12-01
影响因子：
4
通讯作者：
Michaleris, Pan
中科院分区：
文献类型：
--
作者：
Denlinger, Erik R.;Irwin, Jeff;Michaleris, Pan
开发了一种有限元建模策略，以预测增材制造（AM）大型零件（米级）中的变形累积。使用混合安静的非活性元素激活策略结合自适应粗化进行三维热弹塑性分析。在模拟开始时，在材料沉积开始之前，从分析中移除与沉积材料对应的元素，然后在安静状态下将元素逐层引入模型中，材料属性使它们不相关。当移动能量源施加到零件上时，通过在能量源施加到元件上时恢复实际材料属性，元件被切换到激活状态。还实现了逐层粗化策略，在构建的较低层中合并元素，使得当在构建的顶部添加元素时，在下面合并元素，从而在整个模拟中保持模型中的低自由度。建模策略的有效性进行了证明和实验验证的大型电子束沉积Ti-6Al-4V部分组成的107个沉积层。仿真结果与实验结果吻合较好，最大误差为29%。
A finite element modeling strategy is developed to allow for the prediction of distortion accumulation in additive manufacturing (AM) large parts (on the order of meters). A 3D thermoelastoplastic analysis is performed using a hybrid quiet inactive element activation strategy combined with adaptive coarsening. At the beginning for the simulation, before material deposition commences, elements corresponding to deposition material are removed from the analysis, then elements are introduced in the model layer by layer in a quiet state with material properties rendering them irrelevant. As the moving energy source is applied on the part, elements are switched to active by restoring the actual material properties when the energy source is applied on them. A layer by layer coarsening strategy merging elements in lower layers of the build is also implemented such that while elements are added on the top of build, elements are merged below maintaining a low number of degrees of freedom in the model for the entire simulation. The effectiveness of the modeling strategy is demonstrated and experimentally validated on a large electron beam deposited Ti-6Al-4V part consisting of 107 deposition layers. The simulation and experiment show good agreement with a maximum error of 29%.