Evaluation of fatigue life of adhesively bonded aluminum single-lap joints using interfacial parameters

This work experimentally studies the effect on adhesive dimensions on the fatigue strength of epoxy adhesively bonded aluminum single-lap joints. Various types of single-lap specimens with different overlap lengths and adhesive thicknesses were used in the experimental program to investigate the effect of bonding dimensions on fatigue strength. Experimental results indicate that under the fixed average shear stress condition, the larger adhesive thickness detrimentally affects fatigue strength. Similarly, the fatigue resistance decreases as the overlap increases except for the specimens with an adhesive thickness of 0.5 mm. The finite element method was adopted herein to obtain the local stress states at the interface between the adhesive and the adherend. Three selected parameters based on the simulated interfacial stresses were considered to correlate with the fatigue life data of all specimens with various adhesive dimensions. These parameters are maximum interfacial peeling stress, maximum interfacial shear stress and a linear combination of interfacial peeling stress and shear stress. These three interfacial parameters yield much better correlation results than the bulk average stress parameter. The evaluation results demonstrate that peeling stress and the linear combination of interfacial peeling stress and shear stress provide better correlation results than the interfacial shear parameters, revealing that the interfacial peeling stress is the main driving force of the fatigue failure of the single-lap joints.

[1]  Anthony J. Kinloch,et al.  The Fatigue and Durability Behaviour of Automotive Adhesives. Part I: Fracture Mechanics Tests , 1997 .

[2]  José Costa,et al.  Fatigue behaviour of composite adhesive lap joints , 2002 .

[3]  Robert D. Adams,et al.  The effect of temperature on the strength of adhesive joints , 1992 .

[4]  Crocombe A.D,et al.  Assessing stress state and mean load effects on the fatigue response of adhesively bonded joints , 1999 .

[5]  P. R. Underhill,et al.  The effect of warm water surface treatments on the fatigue life in shear of aluminum joints , 2006 .

[6]  R. I. Mackie,et al.  The effects of ageing and environment on the fatigue life of adhesive joints , 1992 .

[7]  J. Gonçalves,et al.  Evaluation of stress concentration effects in single-lap bonded joints of laminate composite materials , 2005 .

[8]  P. R. Underhill,et al.  The dependence of the fatigue life of adhesive joints on surface preparation , 2006 .

[9]  J. Vinson,et al.  Fatigue Behavior of Bonded Joints in Composite Material Structures , 1975 .

[10]  G. Smith,et al.  Cyclic stress durability testing of lap shear joints exposed to hot-wet conditions , 2000 .

[11]  Robert D. Adams,et al.  The strength of adhesively bonded T-joints , 2002 .

[12]  R. Bálková,et al.  Testing of adhesives for bonding of polymer composites , 2002 .

[13]  J. G. Broughton,et al.  Variable modulus adhesives: an approach to optimised joint performance , 2005 .

[14]  Homayoun Hadavinia,et al.  Predicting the service-life of adhesively-bonded joints , 2000 .

[15]  M. Bowditch,et al.  The durability of adhesive joints in the presence of water , 1996 .

[16]  Anthony J. Kinloch,et al.  The Fatigue and Durability Behaviour of Automotive Adhesives. Part III: Predicting the Service Life , 1998 .

[17]  Chun-Gon Kim,et al.  Failure mode and strength of uni-directional composite single lap bonded joints with different bonding methods , 2006 .

[18]  A. Chateauminois,et al.  A new testing methodology for the assessment of fatigue properties of structural adhesives , 1996 .

[19]  A. Beevers,et al.  Performance of bi-adhesive bonded aluminium lap joints , 2003 .

[20]  Stefanie Feih,et al.  Adhesive and composite failure prediction of single-L joint structures under tensile loading , 2004 .

[21]  P. K. Mallick,et al.  Effect of spew geometry on stresses in single lap adhesive joints , 1998 .

[22]  A. Morais,et al.  Strength of adhesively bonded stainless steel joints , 2003 .

[23]  T. Sugibayashi,et al.  Benchmark tests on adhesive strengths in butt, single and double lap joints and double-cantilever beams , 1996 .

[24]  P.M.S.T. de Castro,et al.  A three-dimensional finite element model for stress analysis of adhesive joints , 2002 .