Novel fiber orientation evaluation method for CFRP/CFRTP based on measurement of anisotropic in-plane thermal diffusivity distribution
Novel fiber orientation evaluation method for CFRP/CFRTP based on measurement of anisotropic in-plane thermal diffusivity distribution
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DOI：
10.1016/j.compscitech.2016.12.006
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发表时间：
2017-03-01
影响因子：
9.1
通讯作者：
Nagano, Hosei
中科院分区：
文献类型：
--
作者：
Fujita, Ryohei;Nagano, Hosei
本研究提出了一种基于热扩散率测量的评价片状纤维增强材料纤维取向的新方法。该实验装置由激光器、函数发生器、显微镜和热像仪组成。利用激光光斑对样品表面进行周期性加热，利用锁相式热像仪测量样品背面的热响应，得到面内热扩散率分布。这种热扩散率角分布与纤维取向分布(FOD)直接相关。在本研究中，可以得到FOD密度函数来拟合热扩散率角分布。首先，使用已知FOD的单向(UD)碳纤维增强塑料验证了该方法的可行性。UD样品的FOD最大可估计在0.3度以内。然后将该方法应用于具有不连续纤维的碳纤维增强热塑性塑料(CFRTP)样品。测量了热扩散率的角分布，并对结果进行了FOD拟合。FOD可从纤维取向角和强度两个方面进行评价。最后，使用长纤维热塑性塑料直接法成型的CFRTP薄板进行了测绘测量。该测绘方法适用于大尺度样本的测量。(C)2016爱思唯尔有限公司。保留所有权利。
This study proposes a new method for evaluating fiber orientation of sheet-like fiber reinforced materials based on thermal diffusivity measurements. The experimental apparatus comprises a laser, function generator, microscope, and thermographic camera. The surface of a sample is heated periodically by a laser spot, and the thermal response on the rear side of the sample is measured by a lock-in thermographic camera to obtain in-plane thermal diffusivity distribution. This thermal diffusivity angular distribution is directly related to the fiber orientation distribution (FOD). In this study, FOD density function can be obtained to fit the thermal diffusivity angular distribution. At first, the feasibility of this method was verified using a unidirectional (UD) carbon fiber reinforced plastic with a known FOD. The FOD of the UD sample can be estimated within 0.3 degrees at the maximum. The method was then applied to a carbon fiber reinforced thermoplastic (CFRTP) sample having discontinuous fibers. The thermal diffusivity angular distributions were measured, and the FOD fitting method was applied to the results. The FOD can be evaluated from the fiber orientation angle and strength. Finally, mapping measurements were conducted using a CFRTP sheet molded by the long fiber thermoplastic-direct method. The mapping measurement is valid for the measurement of large scale samples. (C) 2016 Elsevier Ltd. All rights reserved.