High performance estimations of delamination of graphite/epoxy laminates with electric resistance change method

Delamination of laminated composites is usually invisible or difficult to detect visually. Delamination causes low reliability for primary structures. Automatic systems for in-service delamination identifications are desired to improve low reliability. The present study employs an electric resistance change method for delamination detection. Since the method adopts reinforcement carbon fiber itself as sensors for delamination detection, this method does not reduce static or fatigue strength; also, the method is applicable to existing structures. Authors have found that the electric resistance change method with response surfaces is very effective experimentally and analytically. However, a large error of estimation remains for estimation of delamination location. In the present study, a new data processing procedure is proposed to improve performance of estimations of delamination location. The new method is applied to laminated composite beams. A delamination crack of a laminated composite beam is monitored with the new method using FEM analyses. As a result, the method reveals excellent performance of estimations of delamination location even for new data not used in regression equations.

[1]  D.D.L. Chung,et al.  Carbon‐Fiber‐Reinforced Concrete as an Intrinsically Smart Concrete for Damage Assessment during Dynamic Loading , 1995 .

[2]  Hiroaki Yanagida,et al.  Hybrid composites with self-diagnosing function for preventing fatal fracture , 2001 .

[3]  Dae-Cheol Seo,et al.  Damage detection of CFRP laminates using electrical resistance measurement and neural network , 1999 .

[4]  D. Chung,et al.  Carbon fiber reinforced concrete for smart structures capable of non-destructive flaw detection , 1993 .

[5]  Karl Schulte,et al.  Load and failure analyses of CFRP laminates by means of electrical resistivity measurements , 1989 .

[6]  Phil E. Irving,et al.  Fatigue damage characterization in carbon fibre composite materials using an electrical potential technique , 1998 .

[7]  Xiaojun Wang,et al.  Sensing delamination in a carbon fiber polymer-matrix composite during fatigue by electrical resistance measurement , 1997 .

[8]  S. Al-Hassani,et al.  ELECTRICAL RESISTANCE MEASUREMENT TECHNIQUE FOR DETECTING FAILURE IN CFRP MATERIALS AT HIGH STRAIN RATES , 1994 .

[9]  G. Giraud,et al.  In-situ monitoring of damage in CFRP laminates by means of AC and DC measurements , 2001 .

[10]  A. Chateauminois,et al.  In situ detection of damage in CFRP laminates by electrical resistance measurements , 1999 .

[11]  Shiv P. Joshi,et al.  Damage detection in CFRP by electrical conductivity mapping , 2001 .

[12]  Akira Todoroki,et al.  The effect of number of electrodes and diagnostic tool for monitoring the delamination of CFRP laminates by changes in electrical resistance , 2001 .

[13]  Akira Todoroki,et al.  Composite Materials. Electric Resistance Change Method for Identification of Embedded Delamination of CFRP Plates. , 2001 .

[14]  F. J. Arendts,et al.  Electrical crack length measurement and the temperature dependence of the mode I fracture toughness of carbon fibre reinforced plastics , 1993 .

[15]  Douglas C. Montgomery,et al.  Response Surface Methodology: Process and Product Optimization Using Designed Experiments , 1995 .

[16]  M. Miyayama,et al.  Foreseeing of Fracture in CFGFRP Composites by Measuring Electrical Resistance. , 1992 .

[17]  Akira Todoroki,et al.  Measurement of orthotropic electric conductance of CFRP laminates and analysis of the effect on delamination monitoring with an electric resistance change method , 2002 .

[18]  A. Todoroki,et al.  Health monitoring of internal delamination cracks for graphite/epoxy composites by electric potential method , 2000 .

[19]  A. Todoroki,et al.  Evaluation of Orthotropic Electrical Resistance for Delamination Detection of CFRP by Electrical Potential Method. , 1998 .

[20]  Hideo Kobayashi,et al.  Application of Electric Potential Method to Smart Composite Structures for Detecting Delamination , 1995 .

[21]  Akira Todoroki,et al.  Delamination monitoring of graphite/epoxy laminated composite plate of electric resistance change method , 2002 .

[22]  Karl Schulte,et al.  Non-destructive testing of FRP by d.c. and a.c. electrical methods , 2001 .

[23]  Kazumasa Moriya,et al.  A study on flaw detection method for CFRP composite laminates. (1st report). The measurement of crack extension in CFRP composites by electrical potential method. , 1988 .

[24]  Peter Schwartz,et al.  Monitoring bending fatigue in carbon-fibre/epoxy composite strands: a comparison between mechanical and resistance techniques , 2001 .