A Comparative Study of Finite Element Models for the Bonded Repair of Composite Structures

Odi, Randolph; Friend, C. M.

doi:10.1177/0731684402021004257

Cited by 28 publications

(7 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Normal (sn) and shear (ttn) stresses in the adhesive layer for scarf assemblies are practically constant for isotropic adherends or unidirectional composites [31,43,45]. This can be justified in light of a smaller load eccentricity than in lap or strap geometries [27,70] and by the adherend tapering effect at the scarfed region [23,27], and helps to the high efficiency of these assemblies relatively to the bond area.…”

Section: Stress Analysismentioning

confidence: 99%

Numerical evaluation of three-dimensional scarf repairs in carbon-epoxy structures

Pinto¹,

Campilho

Moura

et al. 2010

International Journal of Adhesion and Adhesives

View full text Add to dashboard Cite

The widespread employment of carbon-epoxy laminates in high responsibility and severely loaded applications introduces an issue regarding their handling after damage. Repair of these structures should be evaluated, instead of their disposal, for cost saving and ecological purposes. Under this perspective, the availability of efficient repair methods is essential to restore the strength of the structure. The development and validation of accurate predictive tools for the repairs behaviour are also extremely important, allowing the reduction of costs and time associated to extensive test programmes. Comparing with strap repairs, scarf repairs have the advantages of a higher efficiency and the absence of aerodynamic disturbance. This work reports on a numerical study of the tensile behaviour of three-dimensional scarf repairs in carbon-epoxy structures, using a ductile adhesive (Araldite s 2015). The finite elements analysis was performed in ABAQUS s and Cohesive Zone Modelling was used for the simulation of damage onset and growth in the adhesive layer. Trapezoidal cohesive laws in each pure mode were used to account for the ductility of the specific adhesive mentioned. A parametric study was performed on the repair width and scarf angle. The use of over-laminating plies covering the repaired region at the outer or both repair surfaces was also tested as an attempt to increase the repairs efficiency. The obtained results allowed the proposal of design principles for repairing composite structures.

show abstract

Section: Stress Analysismentioning

confidence: 99%

Numerical evaluation of three-dimensional scarf repairs in carbon-epoxy structures

Pinto¹,

Campilho

Moura

et al. 2010

International Journal of Adhesion and Adhesives

View full text Add to dashboard Cite

show abstract

“…Failure loads were compared with previously published experimental work, and the results were found to be in agreement. Odi and Friend [4] presented a stress comparison of three different numerical approaches to simulate tensile loaded stepped and scarf repairs (3 • scarf angle). Regarding scarf repairs, it was concluded that shear stresses in the adhesive are practically constant, leading to a high efficiency of the repair, as the adhesive fails simultaneously at all bond length.…”

Section: Introductionmentioning

confidence: 99%

Stress and failure analyses of scarf repaired CFRP laminates using a cohesive damage model

Campilho¹,

Moura

Domingues³

2007

Journal of Adhesion Science and Technology

View full text Add to dashboard Cite

This study describes stress and failure analyses of tensile loaded repaired Carbon Fibre Reinforced Composite (CFRP) laminates, using scarf configuration. A numerical model including interface finite elements was used to obtain peel and shear-stress distributions in the directions tangent and normal to the scarf. These stresses were evaluated at several locations in the repair, namely in the middle of the adhesive, at interfaces between adhesive and patch, and between adhesive and parent material. Several scarf angle values were considered in the analysis. A cohesive mixed-mode damage model was also used to carry out the failure analysis, in order to assess the efficiency of the repairs, for different stacking sequences. A study was performed to evaluate the influence of the mechanical properties of the adhesive and parent laminate/adhesive and adhesive/patch interfaces on the strength and failure modes of the joint. It was concluded that the strengths of the adhesive and interfaces are more important than the fracture properties in the failure process of the repair. It was also verified that the strength of the repair increased exponentially with the scarf angle reduction.

show abstract

“…These repair processes are generally cheaper and more effortless for composite structures by comparison with replacing these materials. 4–7…”

Section: Introductionmentioning

confidence: 99%

An experimental study on low velocity impact behavior of thermoplastic composites repaired by composite patches

Zorer

Özdemir

Öztoprak

2020

Journal of Composite Materials

View full text Add to dashboard Cite

In this study, low velocity impact behavior of E-glass fiber-reinforced thermoplastic composites repaired by pressing external laminated composite patches was investigated by experimental methods. Thermoplastic composites were manufactured from polypropylene granules with two different fiber contents of 40 wt. % and 60 wt. %. Repaired specimens were prepared by using unidirectional E-glass reinforced polypropylene based thermoplastic prepregs. In order to compare the low velocity impact behavior of the repaired and unrepaired specimens, a number of single impact tests (ranging from energy levels of 10 J to 50 J) were carried out through a drop weight impact test machine with a hemispherical impactor. Low-velocity impact response of the specimens was investigated with cross-examining contact force-deformation curves and damaged specimens. Impact damages occurred in the upside and bottom surfaces of the composites were recorded from the visual inspection and compared for repaired and unrepaired specimens. According to experimental results, bending stiffness and maximum contact force of the specimens having fiber content of 60 wt.% are higher than those of 40 wt.%. Moreover, it was concluded that the patch repaired specimens have achieved a better performance in terms of maximum contact force and absorbed energy compared to the intact specimens.

show abstract

A Comparative Study of Finite Element Models for the Bonded Repair of Composite Structures

Cited by 28 publications

References 18 publications

Numerical evaluation of three-dimensional scarf repairs in carbon-epoxy structures

Numerical evaluation of three-dimensional scarf repairs in carbon-epoxy structures

Stress and failure analyses of scarf repaired CFRP laminates using a cohesive damage model

An experimental study on low velocity impact behavior of thermoplastic composites repaired by composite patches

Contact Info

Product

Resources

About