This paper presents a prediction and evaluation of delamination factor in use of twist drill, candle stick drill and saw drill. The approach is based on Taguchi’s method and the analysis of variance (ANOVA). An ultrasonic C-Scan to examine the delamination of carbon fiber-reinforced plastic (CFRP) laminate is used in this paper. The experiments were conducted to study the delamination factor un...

The purpose of this paper is to review recent research on the applications of existing non-destructive testing (NDT) techniques, especially radio frequency (RF) NDT, for carbon-fibre reinforced plastics (CFRP) composites. Electromagnetic properties of CFRP composites that are associated with RF NDT are discussed first. The anisotropic characteristic of the conductivity and the relationship betw...

Two different design problems are commonly encountered by highway bridge maintenance engineers: the upgrade of existing members to handle increased load demand, or the repair of bridge members which have experienced impact events due to overheight vehicles. This paper shows that through the use of carbon fiber reinforced (CFRP) materials highway bridge girders can be effectively strengthened or...

Carbon fiber reinforced polymer (CFRP) sheets can be externally bonded for retrofit of concrete structures, improving flexure and sheer strength in the concrete. The key to CFRP sheets is the bond to the concrete, as bond is the means to transfer stress between the tow sheet and the concrete. Experimentation has been conducted to test a current market fiber-resin system, and to develop a resin ...

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...

The present paper is concerned with modelling damage and fracture in notched woven fabric composites. Previous experimental work has shown that damage at a notch in a variety of GFRP and CFRP composites based on woven fabric reinforcement comprises matrix damage and fibre tow fracture along the plane of maximum stress. It is these experimental observations that inform the failure modelling deve...

Drilling-induced delamination is among the major concerns of applying the fiber-reinforced composite materials in various industries. Core drill ossesses the advantage for reducing the delamination by distributing the drilling thrust force toward the drill periphery. The thrust force of core rill varying with the conditions in drilling carbon fiber reinforced plastic (CFRP) is experimentally in...

We present an optical sensing methodology to estimate the fatigue damage state of structures made of carbon fiber reinforced polymer (CFRP), by measuring variations on the surface roughness. Variable amplitude loads (VAL), which represent realistic loads during aeronautical missions of fighter aircraft (FALSTAFF) have been applied to coupons until failure. Stiffness degradation and surface roug...