Characterization and Effects of Fiber Pull-Outs in Hole Quality of Carbon Fiber Reinforced Plastics Composite.

Sina Alizadeh Ashrafi,Kevin Wandro,Peter Miller,Dave Kim

doi:10.3390/ma9100828

Sina Alizadeh Ashrafi, Kevin Wandro + Show 2 more

Open Access

https://doi.org/10.3390/ma9100828

Copy DOI

Abstract

Hole quality plays a crucial role in the production of close-tolerance holes utilized in aircraft assembly. Through drilling experiments of carbon fiber-reinforced plastic composites (CFRP), this study investigates the impact of varying drilling feed and speed conditions on fiber pull-out geometries and resulting hole quality parameters. For this study, hole quality parameters include hole size variance, hole roundness, and surface roughness. Fiber pull-out geometries are quantified by using scanning electron microscope (SEM) images of the mechanically-sectioned CFRP-machined holes, to measure pull-out length and depth. Fiber pull-out geometries and the hole quality parameter results are dependent on the drilling feed and spindle speed condition, which determines the forces and undeformed chip thickness during the process. Fiber pull-out geometries influence surface roughness parameters from a surface profilometer, while their effect on other hole quality parameters obtained from a coordinate measuring machine is minimal.

Highlights

IntroductionAircraft manufacturers are putting major effort into producing more fuel-efficient airplanes
Aircraft manufacturers are putting major effort into producing more fuel-efficient airplanes.This effort will drastically reduce airplane carbon emissions and help improve the environment in a sustainable fashion
Through drilling experiments of carbon fiber-reinforced plastic composites, this study investigates the the impact of varying drilling feed and speed conditions on fiber pull-out geometries and the impact of varying drilling feed and speed conditions on fiber pull-out geometries and the resulting resulting hole quality parameters

Summary

Introduction

Aircraft manufacturers are putting major effort into producing more fuel-efficient airplanes. This effort will drastically reduce airplane carbon emissions and help improve the environment in a sustainable fashion. Fuel-efficient airplane designs often involve the switch to carbon fiber-reinforced plastic composites (CFRP). The superior advantages of CFRP over conventional metallic materials, include high specific strength, high stiffness, high fatigue resistance, and low thermal expansion. These advantages have given rise to CFRP composite applications in many transportation industries. The conventional drilling process leads to various CFRP hole quality issues, such as inconsistent hole size, roundness, and surface profile, as well as entry/exit delamination, inter-laminar crack propagation, and fiber

Methods

Results

Conclusion