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由于碳纤维增强复合材料(CFRP)具有各向异性的特点,在其钻削加工中极易形成分层、撕裂以及毛刺等加工缺陷,而分层对碳纤维层合板构件的性能影响最大,因而建立一套准确的针对分层缺陷的检测、描述以及评价方法对层合结构碳纤维复合材料的有效应用具有重大意义。从分层缺陷的形成机理出发,通过对现有分层缺陷的检测以及评价体系的分析,提出了基于高频超声扫描显微镜(SAM)来进行分层缺陷检测评价的三维体积分层因子评价方法,并针对T800/X850碳纤维单向层合板对该方法进行了定征试验,最后通过对实际加工孔的分层缺陷的评价,综合对比了三维体积分层因子评价方法与传统评价方法的应用效果。结果表明:分层缺陷是由力热耦合引起的层间粘结失效,出口处更为严重;用超声扫描显微镜检测分层,可检测不少于8层的碳纤维复合材料,至少可以清晰表达5层的内部分层特征;分层会发生隔层传播,并且两个相邻铺层为同向的层间结合强度最好,不易产生隔层传播;三维体积分层因子可以更准确清晰地评价复合材料层合结构的内部缺陷。
Due to the anisotropy of carbon fiber reinforced composites (CFRP), it is easy to form processing defects such as delamination, tearing and burrs during drilling, and stratification has the greatest impact on the performance of carbon fiber laminates. Therefore, CFRP A set of accurate detection, delineation and evaluation methods for delamination defects is of great significance to the effective application of laminated composite carbon fiber composites. Based on the formation mechanism of delamination defects, a three-dimensional volume fractionation factor evaluation method based on high-frequency ultrasonic scanning microscopy (SAM) for delamination detection was proposed based on the detection of existing delamination defects and the evaluation system. , And the method of T800 / X850 carbon fiber unidirectional laminates was tested. Finally, through the evaluation of the delamination defects in the actual machined hole, the application effect of the three-dimensional volume fractionation factor evaluation method and the traditional evaluation method was comprehensively compared . The results show that the delamination defect is the failure of interlayer bonding caused by the coupling of force and heat and the outlet is more serious. The delamination can detect no less than 8 layers of carbon fiber composite by ultrasonic scanning microscopy, at least 5 The inner stratification of strata; the stratification will occur the interlayer propagation, and the bonding strength between the two adjacent strata in the same direction is the best, which is not easy to produce interlayer propagation; the three-dimensional volume stratification factor can be more accurately and clearly evaluated Internal defects of composite laminates.