F. REPAIR
oral
Durability of Epoxy Adhesives used to Bond CFRP Laminates to
Concrete Structures
S Cabral-Fonseca, MP Rodrigues, MI Eusébio (National Lab of Civil Eng) JP Nunes (Minho
Univ)
This work presents an experimental program undertaken in order to evaluate the durability of
three types of commercial epoxy adhesives used for bonding carbon-fibre-reinforced-plastics
(CFRP) to concrete structural elements on their rehabilitation. (F21:1)
Representative Joint Approach to Repair Designs
C Wang, A Gunnion (DSTO)
This paper presents an inclusion model for the design and analysis of adhesively bonded and
bolted repairs to composite laminates. By treating the repair as an equivalent inclusion, the
load carried by the repair patch can be determined using the inclusion analogy for arbitrary
elliptical cutouts. The model is verified against finite element computation and experimental
testing. (F21:2)
Measurement of the Fracture Toughness of the Metal-Composite
Interface in Composite Repair Systems for Steel Pipework
M Robinson, A Al-Maskari, G Gibson, S Frost (Newcastle Univ)
This paper describes the fracture mechanics approach behind the water pressure ‘blow-off
test for characterising the failure behaviour of composite repairs on steel tubes. The
technique enables the fracture toughness of the metal/composite interface to be determined
at the point where failure initiates. (F21:3)
Investigation of Composite Repair Method by Liquid Resin Infusion
M Hauthier, D Lévêque, C Huchette (ONERA) P Olivier (Univ de Toulouse)
“Conventional” repair procedures for impacted composite structures (i.e. patches) are timeconsuming, and must be performed by highly qualified staff. In this paper a cost-effective and
simple repair method by liquid resin infiltration is studied. The liquid resin is used to fill in the
damage region organised as a crack network. (F21:4)
Mechanical Behaviour of Concrete Columns Coated by Composite
Materials with Different Staking Sequences
H Bouchelaghem, A Bezazi (Univ of Guelma) F Scarpa (Univ of Bristol)
We describe a study undertaken on a series of columns reinforced by composite materials
glass/polyester with several lay ups under uniaxial compression loading. The reinforced
columns show an increase up to 70% in rigidity and failure load compared with non-reinforced
ones, when only two plies of composite material are used. (F21:5)
14.10
F. REPAIR
Optimal Design of a Composite Scarf Repair Patch under Uniaxial
Tension Load
T Breitzman, B Cook (US Air Force RL) E Iarve (Univ of Dayton RI)
An optimal design algorithm was used to determine the repair fiber angles that minimize the
stress in the adhesive of the repair joint. The strength was predicted by analysis using the
Critical Failure Volume (CFV) approach for fiber failure. Excellent agreement was seen
between predicted and tested strengths. (F21:6)
Optimisation of Patched Repair for CFRP Laminates
P Cheng, X Gong, S Aivazzadeh (Bourgogne Univ)
The aim of this study is to optimise the patch-repaired composite structure. The tension tests
on specimens have been performed to observe failure modes. Finite element analysis has
been used to identify the most critical zones. The effect of some patch?s parameters on the
performance of the system has been discussed. (F21:7)
Bonded Composite Patch to Repair Metallic Structures: Fatigue
Behaviour of a Disbond
P Madelpech, S Juaneda, M Pradels (CEAT)
The main difficulty for the use of composite patches to repair damaged metallic structures is
the lack of confidence in the bond. One possibility is to adopt a damage tolerance approach
for the disbond. In that frame, this study gives a model of the disbond propagation, the law
being obtained by test results. (F21:8)
Strength Response of Composite Laminate with Multiple Holes for
Repair
E Dan-Jumbo, R Keller, B Westerman (The Boeing Company) W Chan (Univ of Texas)
An experimental mechanics investigation was conducted to determine the effects of hole size,
multiple hole damage, and failure modes using different hole patterns and stacking
sequences on structural repair laminates. Presented are the experimental procedure, different
strength responses, associated failure modes, and any repair implications. (F21:9)
Quality Assessment of Bonded Joints for Repair Purposes with
Adhesive Films and Laminating Resins
A Rodriguez-Bellido, S Mahdi (Airbus) J Costa, J Renart (Univ de Girona) JM Alvarez Pintado,
MA de la Torre (INTA)
A comparison between the fracture toughness of bonded joints manufactured with two
adhesive films and two laminating resins is presented with the objective to assess their quality
for repair purposes. Experimental procedures, as the use of different standards or the effect
of stiffening the adherents with metal plates are investigated and discussed. (F21:10)