CBL - Campus del Baix Llobregat

Projecte llegit

Títol: Structural analysis of adhesive performance in aircraft repair patches made with adhesive bonded joints

Estudiants que han llegit aquest projecte:

Director/a: ROJAS GREGORIO, JOSEP IGNASI

Departament: FIS

Títol: Structural analysis of adhesive performance in aircraft repair patches made with adhesive bonded joints

Data inici oferta: 02-12-2022     Data finalització oferta: 02-07-2023


Estudis d'assignació del projecte:
    GR ENG SIST AEROESP
Tipus: Individual
 
Lloc de realització: EETAC
 
Nom del segon director/a (UPC): Dr.-Eng. Siddharth Pitta
Departament 2n director/a:
 
Paraules clau:
adhesive; adhesive bonding; joints; aircraft; repair patches; static analysis; mechanical properties; structures
 
Descripció del contingut i pla d'activitats:
In this project, the mechanical properties and static loading behavior of several adhesive bonded joints used commonly as aircraft repair patches is analyzed numerically with finite element analysis (FEA) software. If possible, experiments will be made on samples to validate the numerical results.

The procedure and methodology will be as follows:

1. Literature search and review of relevant bibliography
2. Formation on appropriate software packages (e.g., SolidWorks, Abaqus, Helius Composite Tools, FRANC2D, FRANC3D, etc.)
3. Numerical analysis/finite element analysis (FEA) of the problem:
a. design of the CAD geometry or geometries
b. meshing of the geometry or geometries
c. definition of the physics of the problems and the boundary conditions
d. definition of the solver settings and solving of the fluid problems with suitable solver
e. post-processing and analysis of the obtained results
4. (Preparation of samples for experiments)
5. (Realization of experiments)
6. Processing of (experimental results and) FEA results (and calibration of numerical results from FEA with experimental results, comparison of results, etc.)
7. Draw conclusions from the study
8. Write thesis and prepare final presentation

More info can be found in the project descriptions and articles that can be found here:
https://www.researchgate.net/project/Comparison-of-the-response-of-different-configurations-of-aircraft-repair-patches-under-static-and-dynamic-loading
 
Overview (resum en anglès):
The components of an aircraft such as the frame, fuselage, wings, stabilizers, etc. are the so-called aircraft structures. They are usually made from a combination of materials including aluminum alloys, titanium, composites, and other advanced materials. The use of aluminum in aircraft allows for lighter, stronger structures that require less fuel to fly, resulting in improved performance and range and reduced operating costs. Aluminum alloys used in aircraft have high strength-to-weight ratios and good fatigue resistance, making them ideal for structures and fasteners.

After construction, the structures undergo rigorous testing and inspection to verify their strength and durability, including static and fatigue tests that simulate the stress the structure will experience in flight. The focus of this thesis is on the static testing of a bonded joint used in aircraft construction.

Bonded joints are a type of joining technique used in aircraft construction where two or more components are joined together by adhesive materials, often a type of epoxy resin. These joints help distribute stress evenly throughout the structure. However, in accordance with the results obtained in this project, the stress over a joint is not uniform. The static tests are performed using the software Abaqus CAE, which is based on Finite Element Analysis (FEA). In FEA, a digital model of the structure is created, and various loads are applied to see how it responds. In this research, the information from the static tests is used to evaluate the performance of the structure and identify potential areas of weakness or failure.

As said, in this work, different simulations will be carried out for the single lap joint to find out how the adhesive responds when a tensile force is applied to the joined plates, as well as its homologue with rivets, as if it was tested in a universal testing machine, and how the adhesive acts in the case of peeling. In addition, a specimen that resembles a real patch, as it is made up of plates on plates, will also be subjected to these static tests. The results obtained indicate that the stress of the bond is not constant, neither along adhesive nor with rivets, and that the stacking of plates on plates helps to reduce the load in the area to be repaired.

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