Assessment of the effect of defects on mechanical properties of adhesive bonded joints by using non destructive methods

Abstract Mechanical performance of the adhesive joints depends on many parameters including width, depth and continuity of the adhesive layer applied. In this work, lock-in thermography and ultrasound methods were used to detect the dimension of defects of adhesive joints while tensile tests were carried out to assess their strength and stiffness. Both the effect of bond defects and the possibility to use non destructive method for the prediction of strength and stiffness of joints have been discussed considering a statistical analysis of data. Models, useful for predicting mechanical behavior of joints on the basis of their defects, have been developed.

[1]  A. Baker,et al.  Composite Materials for Aircraft Structures , 2004 .

[2]  R. Adams.  Adhesive bonding : science, technology and applications , 2005 .

[3]  D. Palumbo,et al.  Ultrasonic analysis and lock-in thermography for debonding evaluation of composite adhesive joints , 2016 .

[4]  Xavier Maldague,et al.  Theory and Practice of Infrared Technology for Nondestructive Testing , 2001 .

[5]  Riadh Al-Mahaidi,et al.  Investigation of the Parameters that Influence the Accuracy of Bond Defect Detection in CFRP Bonded Specimens Using IR Thermography , 2010 .

[6]  F. Ascione.  The influence of adhesion defects on the collapse of FRP adhesive joints , 2016 .

[7]  Douglas C. Montgomery,et al.  Applied Statistics and Probability for Engineers, Third edition , 1994 .

[8]  Nezih Mrad,et al.  Pulsed thermography for non-destructive evaluation and damage growth monitoring of bonded repairs , 2009 .

[9]  Bonded lap joints of composite laminates with tapered edges , 2006 .

[10]  D. Palumbo,et al.  THERMAL ANALYSIS AND MECHANICAL CHARACTERIZATION OF GFRP JOINTS , 2012 .

[11]  T. Sawa,et al.  Axisymmetric stress analysis of adhesive butt joints of dissimilar solid cylinders subjected to external tensile loads , 1989 .

[12]  Chiaki Sato,et al.  Dynamic stress responses at the edges of adhesive layers in lap strap joints of half-infinite length subjected to impact loads , 2009 .

[13]  Davide Palumbo,et al.  Quantitative damage evaluation of composite materials with microwave thermographic technique: feasibility and new data analysis , 2015 .

[14]  Robert D. Adams,et al.  Nondestructive testing of adhesively-bonded joints , 1997 .

[15]  Peter Cawley,et al.  A review of defect types and nondestructive testing techniques for composites and bonded joints , 1988 .

[16]  Peter Cawley,et al.  Defect types and non-destructive testing techniques for composites and bonded joints , 1989 .

[17]  Steven M. Shepard,et al.  Non-destructive testing of structural composites and adhesively bonded composite joints: pulsed thermography , 2002 .

[18]  A. Higgins.  Adhesive bonding of aircraft structures , 2000 .