Stress Analysis of Adhesively Bonded Double- Lap Joints Subjected to Combined Loading

Adhesively bonded joints are preferred over the conventional methods of joining such as riveting, welding, bolting and soldering. Some of the main advantages of adhesive joints compared to conventional joints are the ability to join dissimilar materials and damage-sensitive materials, better stress distribution, weight reduction, fabrication of complicated shapes, excellent thermal and insulation properties, vibration response and enhanced damping control, smoother aerodynamic surfaces and an improvement in corrosion and fatigue resistance. This paper presents the behavior of adhesively bonded joints subjected to combined thermal loadings, using the numerical methods. The joint configuration considers aluminum as central adherend with six different outer adherends including aluminum, steel, titanium, boronepoxy, unidirectional graphite-epoxy and cross-ply graphite-epoxy and epoxy-based adhesives. Free expansion of the joint in x direction was permitted and stresses in adhesive layer and interfaces calculated for different adherends.

Authors:

• Solyman Sharifi
• Naghdali Choupani

Keywords:

• Thermal stress
• patch repair
• Adhesive joint
• Finiteelement analysis.

References:

[1] A. J. Kinloch, Adhesion and Adhesives: Science and Technology:
Chapman and Hall, 1987.
[2] A. Baldan, "Adhesively-Bonded Joints in Metallic Alloys, Polymers
and Composite Materials: Mechanical and Environmental Durability
Performance", Journal of Materials Science, vol. 39(15), pp. 4729-
4797, 2004.
[3] N. Choupani, "Characterizations of Adhesively Bonded Double-Lap
Joints" Proceedings: International Conference on Advances in
Mechanical Engineering SRM Institute of Science and Technology
Deemed University, Chennai, India: 14-16 December 2006.
[4] J. R. Rice, "Elastic Fracture Mechanics Concepts for Interfacial
Cracks", J. Appl. Mech., vol. 55, pp. 98-103, 1988.
[5] F. Ducept, P. Davies, and D. Gamby, "Mixed Mode Failure Criteria
for a Glass/Epoxy Composite and an Adhesively Bonded
Composite/Composite Joint", International Journal of Adhesion &
Adhesives, vol. 20, pp. 233-244, 2000.
[6] L. M. Butkus, "Environmental Durability of Adhesively Bonded
Joints", The Georgia Institute of Technology, WPAFB OH, Report
No. 97-028D, 14 Oct. 1997.
[7] E. N. Gilbert, B. S. Hayes, and J. C. Seferis, "Nano-Alumina
Modified Epoxy Based Film Adhesives", Polymer Engineering and
Science, vol. 43(5), pp. 1096-1104, 2003.
[8] A. Pirondi and G. Nicoletto, "Mixed Mode I/II Fracture Toughness of
Bonded Joints", International Journal of Adhesion and Adhesives,
vol. 22(2), pp. 109-117, 2002.
[9] Naveen Rastogi, Som R.Sonia & Arvind Nagar, ''Thermal Stresses in
aluminum-to-composite double-lap bonded joints'', Advances in
Engineering Software, vol29, no.3-6, pp273-281, 1998.
[10] N. Choupani, '' Interfacial Mixed-mode Fracture Characterization of
Adhesively Bonded Aerospace Material System" Proceedings of the
6th Conference of Aerospace Society(Aero2007), K. N. Toosi
University of Technology, Tehran, Iran, 24-25 Feb 2007.
[11] N. Choupani, "FE Analysis of Stress Intensity Factors in Adhesively
Bonded Double-lap Specimens" Proceedings: International
Conference on Advances in Mechanical Engineering-2006 (AME
2006), Baba Banda Singh Bahadur Engineering College, Fatehgarh
Sahib, Punjab, India, December 1-3, 2006.