Development of a New Method for T-joint Specimens Testing under Shear Loading

Nonstandard tests are necessary for analyses and
verification of new developed structural and technological solutions
with application of composite materials. One of the most critical
primary structural parts of a typical aerospace structure is T-joint.
This structural element is loaded mainly in shear, bending, peel and
tension. The paper is focused on the shear loading simulations. The
aim of the work is to obtain a representative uniform distribution of
shear loads along T-joint during the mechanical testing. A new
design of T-joint test procedure, numerical simulation and
optimization of representative boundary conditions are presented.
The different conditions and inaccuracies both in simulations and
experiments are discussed. The influence of different parameters on
stress and strain distributions is demonstrated on T-joint made of
CFRP (carbon fibre reinforced plastic). A special test rig designed by
VZLU (Aerospace Research and Test Establishment) for T-shear test
procedure is presented.

• R. Doubrava
• R. Růžek

• T-joint
• shear
• composite
• mechanical testing
• Finite Element analysis
• methodology.

[1] C. E. Bakis et al, Fiber-Reinforced Polymer Composites for
Construction — State-of-the-Art Review. J. Compos. Constr., 6(2),
2002, 73–87.
[2] F. Weyrauch, L. Llopart, F. Strachauer, An Innovative Approach on
Modular Joints for Carbon Fibre Reinforced Structures. Proceedings of
ICCM-17 17th International Conference on Composite Materials, 27 –
31 Jul 2009, Edinburgh, UK, ISSN, 1465-8011.
[3] K.I. Tserpes, G.N. Labeas, Mesomechanical analysis of non-crimp
fabric composite structural parts. Composite Structures. 87(4), 2009,
358–369.
[4] F. Stig, S. Hallström, Assessment of the mechanical properties of a new
3D woven fibre composite material. Composites Science and
Technology, 69(11–12), 2009, 1686–1692.
[5] G. Wachinger, C. Thum, L. Llopart, A. Maier, H. Wehlan, T. Stöven,
New Trends in CFRP Treatment and Surface Monitoring for Automated
Structural Adhesive Bonding. Proceedings of ICCM-17 17th
International Conference on Composite Materials, 27 – 31 Jul 2009,
Edinburgh, UK, ISSN, 1465-8011.
[6] K.I. Tserpes, , Sp. Pantelakis, V. Kappatos, The effect of imperfect
bonding on the pull-out behavior of non-crimp fabric Pi-shaped joints.
Computational Materials Science. 50(4), 2011, 1372–1380.
[7] D.R. Cartié, G. Dell’Anno, E. Poulin, I. K. Partridge, 3D reinforcement
of stiffener-to-skin T-joints by Z-pinning and tufting. Eng. Fracture
Mechanics, 73(16), 2006, 2532–2540.
[8] CERFAC - Cost Effective Reinforcement of Fastener Areas in
Composites. FP7 grant agreement n° 266026,
http://research.cenaero.be/~cerfac.
[9] Femap - Finite Element Modeling And Postprocesing, Version 11.1.2.
Siemens Product Lifecycle Management Software Inc. 2014.
[10] Nastran - NASA STRucture ANalysis. Finite element analysis code.
Version NX/Nastran 8.5. Siemens Product Lifecycle Management
Software Inc. 2013.
[11] M. Asif, Y. Aymat, M. Kashif, Design and Analysis of Grid Stiffened
Composite structure, Lambert Academic Publishing AG&Co.Kg,
Saarbrucken, 2010, ISBN: 978-3-8383-51-1.