Next Article in Journal
Complete Stress–Strain Curves of Self-Compacting Steel Fiber Reinforced Expanded-Shale Lightweight Concrete under Uniaxial Compression
Previous Article in Journal
Studying Grain Boundary Strengthening by Dislocation-Based Strain Gradient Crystal Plasticity Coupled with a Multi-Phase-Field Model
Previous Article in Special Issue
Influence of W Addition on Microstructure and Mechanical Properties of Al-12%Si Alloys
Open AccessArticle

An Experimental and Numerical Study of Repairs on Composite Substrates with Composite and Aluminum Doublers Using Riveted, Bonded, and Hybrid Joints

1
Department of Physics–Division of Aerospace Engineering, Universitat Politècnica de Catalunya, c/ Esteve Terradas 7, 08860 Castelldefels, Spain
2
Department of Strength of Materials and Structural Engineering, Universitat Politècnica de Catalunya, av. Diagonal 647, 08028 Barcelona, Spain
3
Department of Physics, Barcelona Research Centre in Multiscale Science and Technology and Institut de Tècniques Energètiques, av. Eduard Maristany 16, 08019 Barcelona, Spain
*
Author to whom correspondence should be addressed.
Materials 2019, 12(18), 2978; https://doi.org/10.3390/ma12182978
Received: 22 August 2019 / Revised: 9 September 2019 / Accepted: 12 September 2019 / Published: 14 September 2019
(This article belongs to the Special Issue Applications of Al Alloys on Lightweight Structures)
In this work, experimental and numerical analyses of repairs on carbon fiber reinforced epoxy (CFRE) substrates, with CFRE and aluminum alloy doublers typical of aircraft structures, are presented. The substrates have a bridge gap of 12.7 mm (simulated crack), repaired with twin doublers joined with riveted, adhesive bonded, and hybrid joints. The performance of the repairs using different doubler materials and joining techniques are compared under static loading. The experimental results show that riveted joints have the lowest strength, while adhesive bonded joints have the highest strength, irrespective of the doubler material. Finite element analysis (FEA) of the studied joints is also performed using commercial FEA tool Abaqus. In the FEA model, point-based fasteners are used for the rivets, and a cohesive zone contact model is used to simulate the adhesive bond. The FEA results indicate that the riveted joints have higher tensile stresses on the metal doublers compared to the composite doublers. As per the failure modes, interestingly, for hybrid joints using composite doublers, the doublers fail due to net-section failure, while, for hybrid joints using metal doublers, it is the composite substrate that fails due to net-section failure. This suggests vulnerability of the composite structures to mechanical fastener holes. Lastly, the Autodesk Helius composite tool is used for prediction of first-ply failure and ply load distribution, and for progressive failure analysis of the composite substrate. View Full-Text
Keywords: carbon fiber reinforced epoxy composite; substrate; rivets; adhesive bond; hybrid; aluminum alloy; strength carbon fiber reinforced epoxy composite; substrate; rivets; adhesive bond; hybrid; aluminum alloy; strength
Show Figures

Figure 1

MDPI and ACS Style

Pitta, S.; Roure, F.; Crespo, D.; Rojas, J.I. An Experimental and Numerical Study of Repairs on Composite Substrates with Composite and Aluminum Doublers Using Riveted, Bonded, and Hybrid Joints. Materials 2019, 12, 2978.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop