Horak Zdenek, Tichy Petr, Dvorak Karel, Vilimek Miloslav
Department of Technical Studies, College of Polytechnics Jihlava, Tolsteho 16, 58601 Jihlava, Czech Republic.
Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic.
Materials (Basel). 2021 Mar 28;14(7):1654. doi: 10.3390/ma14071654.
Rigid polyurethane (PUR) foam, which has an extensive range of construction, engineering, and healthcare applications, is commonly used in technical practice. PUR foam is a brittle material, and its mechanical material properties are strongly dependent on temperature and strain rate. Our work aimed to create a robust FE model enabling the simulation of PUR foam machining and verify the results of FE simulations using the experiments' results. We created a complex FE model using the Arbitrary Lagrangian-Eulerian (ALE) method. In the developed FE model, a constitutive material model was used in which the dependence of the strain rate, damage initiation, damage propagation, and plastic deformation on temperature was implemented. To verify the FE analyses' results with experimentally measured data, we measured the maximum temperature during PUR foam drilling with different densities (10, 25, and 40 PCF) and at various cutting speeds. The FE models with a constant cutting speed of 500 mm/s and various PUR foam densities led to slightly higher Tmax values, where the differences were 13.1% (10 PCF), 7.0% (25 PCF), and 10.0% (40 PCF). The same situation was observed for the simulation results related to various cutting speeds at a constant PUR foam density of 40 PCF, where the differences were 25.3% (133 mm/s), 10.1% (500 mm/s), and 15.5% (833 mm/s). The presented results show that the ALE method provides a good match with the experimental data and can be used for accurate simulation of rigid PUR foam machining.
硬质聚氨酯(PUR)泡沫在建筑、工程和医疗保健等领域有着广泛的应用,在技术实践中被广泛使用。PUR泡沫是一种脆性材料,其机械材料性能强烈依赖于温度和应变率。我们的工作旨在创建一个强大的有限元(FE)模型,以模拟PUR泡沫加工过程,并使用实验结果验证有限元模拟的结果。我们使用任意拉格朗日-欧拉(ALE)方法创建了一个复杂的有限元模型。在开发的有限元模型中,使用了本构材料模型,其中考虑了应变率、损伤起始、损伤扩展和塑性变形对温度的依赖性。为了用实验测量数据验证有限元分析的结果,我们测量了不同密度(10、25和40磅/立方英尺)的PUR泡沫在不同切削速度下钻孔时的最高温度。切削速度恒定为500毫米/秒且PUR泡沫密度不同的有限元模型得出的Tmax值略高,差异分别为13.1%(10磅/立方英尺)、7.0%(25磅/立方英尺)和10.0%(40磅/立方英尺)。在PUR泡沫密度恒定为40磅/立方英尺、切削速度不同的模拟结果中也观察到了同样的情况,差异分别为25.3%(133毫米/秒)、10.1%(500毫米/秒)和15.5%(833毫米/秒)。给出的结果表明,ALE方法与实验数据匹配良好,可用于精确模拟硬质PUR泡沫加工。