A Comparative Study on Drill Tool Effect on Vibration and Delamination Characteristics of FRPs

ABSTRACT

Drilling is an inevitable process for component assembly which need appropriate control aiming damage reduction. To study such drill-induced damages, Glass and Natural fiber composites with unidirectional (11) and cross-ply lay-up (12) were drilled using Twist and Annular Core drill tool of varying diameters (6 and 8 mm). The derivative of modal analysis (natural frequency, damping) and delamination are the factors considered for the analysis. In the chosen laminates, maximum variation in the natural frequency was observed to be 8.98% in N12 and 8.60% in G12 for twist drill of 8 mm, whereas the core drill of 8 mm contributes to 0.51% and 0.54%. A similar trend was observed in damping factor showing a maximum variation of 26.98% (N12) and 11.30% (N12) with 8 mm twist and core drill, respectively. Similarly, the maximum delamination factor was observed to be 1 .62 and 1.30 with 8 mm core drill in G12 and N12 which is lower than the 6 and 8 mm twist drills. Further, twist drilling experiences both peel-up and push down delamination in N12, N11 which was eliminated by the core drill. Thus, core drill exhibits distinct advantages with reduced damage and retained structural properties.

摘要

钻孔是部件装配的一个不可避免的过程，需要适当的控制以减少损伤. 为了研究这种钻孔引起的损伤, 使用不同直径 (6和8 mm) 的扭转和环形钻芯钻具对具有单向 (11) 和交叉铺层 (12) 的玻璃和天然纤维复合材料进行钻孔. 模态分析的导数 (固有频率, 阻尼) 和分层是分析所考虑的因素. 在选定的层压板中, 观察到对于8 mm的麻花钻, N12和G12的固有频率最大变化分别为8.98%和8.60%，而8 mm的芯钻分别为0.51%和0.54%. 在阻尼系数方面也观察到类似的趋势, 在8 mm麻花钻和取芯钻的情况下, 阻尼系数的最大变化分别为26.98% (N12) 和11.30% (N12). 类似地, 在G12和N12中使用8 mm芯钻观察到的最大分层系数分别为1.62和1.30, 低于6和8 mm麻花钻. 此外, 麻花钻在N12, N11中经历了剥离和下推分层, 这被岩心钻消除. 因此, 岩芯钻具有明显的优点, 减少了损伤并保留了结构特性.

KEYWORDS:

• FRP
• drilling
• modal analysis
• natural frequency
• damping
• delamination

关键词:

• 钻孔
• 模态分析
• 固有频率
• 阻尼
• 分层

Acknowledgements

The authors acknowledge the support rendered by the Head of the Department and Institution of RMK College of Engineering and Technology to conduct the experiments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors disclose that no funding has been received from any of the agencies to conduct and prepare this research article.