A micro-scale cutting model for UD CFRP composites with thermo-mechanical coupling
A micro-scale cutting model for UD CFRP composites with thermo-mechanical coupling
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DOI：
10.1016/j.compscitech.2017.09.028
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发表时间：
2017-12-01
影响因子：
9.1
通讯作者：
Liu, Wing Kam
中科院分区：
文献类型：
--
作者：
Cheng, Hui;Gao, Jiaying;Liu, Wing Kam
单向碳纤维复合材料（UD CFRP）结构的切削加工是CFRP加工的基本单元，是一个复杂的热力耦合过程。为了揭示单向碳纤维复合材料（UD CFRP）微切削加工的变形机理和预测切削力，提出了一种基于微观RVE的热力耦合单向CFRP微切削加工断裂模型，该模型采用相对简单的基于损伤的断裂方法，捕捉了纤维、基体和界面的破坏模式。基于切削过程中的塑性能量耗散和摩擦生热，建立了细观尺度下的热力耦合模型。纤维，基体和界面区域的故障模型的应用取决于这三个阶段的每一个的材料特性。基于上述模型，对不同纤维取向的单向碳纤维复合材料进行了数值模拟，预测了单向碳纤维复合材料中不同构件的变形和受力情况。进行了与模拟中考虑的相同纤维取向的切割实验，以验证力和变形结果。预测的力和变形模式与我们的实验证据吻合得很好。通常，无论纤维取向如何，切割力都大于推力。当纤维取向接近90度时，切割力达到最大值，但推力在不同情况下变化不大。当纤维取向为锐角时，纤维的变形远小于切割角为钝角时的变形。表面粗糙度随切削角的变化趋势与纤维变形相同。(C)2017爱思唯尔有限公司版权所有。
Cutting a unidirectional carbon fiber-reinforced polymer (UD CFRP) structure is the basic unit for CFRP machining, which is a complex thermal-mechanically coupled process. To reveal the deformation mechanism and predict cutting force in UD CFRP micro cutting, a micro-scale fracture model for UD CFRP cutting with thermal-mechanical coupling is demonstrated in this paper, which captures the failure modes for fibers, matrix and the interface based on a micro-level RVE using a relatively simple damage based fracture method. The thermal-mechanical coupling model at the micro scale is developed on the basis of the plastic energy dissipation and frictional heating during cutting. Failure models for the fiber, matrix and interface region are applied depending on the material properties of each of these three phases. Numerical simulations based on the above model with different fiber orientations were performed to predict the deformation and forces of different components in UD CFRP. Cutting experiments with the same fiber orientations as considered in the simulations were carried out to validate the force and deformation results. The predicted force and deformation patterns match well with evidence from our experiments. In general, the cutting force is larger than the thrust force regardless of fiber orientation. The cutting force reaches a maximum as the fiber orientation approaches 90, but thrust forces do not vary substantially across cases. When the fiber orientation is acute, the deformation of fibers is much smaller than when the cutting angle is obtuse. Surface roughness follows the same trend with cutting angle as fiber deformation. (C) 2017 Elsevier Ltd. All rights reserved.