http://hdl.handle.net/10256/23104 Sun, 01 Jun 2025 04:39:14 GMT 2025-06-01T04:39:14Z http://hdl.handle.net/10256/23691 Design optimization of the step/scarf repair of an aeronautical panel targeting the maximum compressive strength and the minimization of material removal Psarras, S.; Giannoutsou, M.P.; Kostopoulos, V. The design and evaluation of different elliptical composite repair patches, for the purpose of forming an optimum patch design, is a complex and time-consuming process. Geometry and effectiveness of a repair patch depend on various parameters, such as length of step, dimensions of major and minor semi-axes of each ply’s ellipse, as well as on each ply’s ellipse’s eccentricity. The optimum values of the previously mentioned parameters are strongly related to layup and loading conditions. Consequently, examination of many different patch geometries is crucial, in order to find an optimum patch which will meet the needs and demands of strength and geometric restrictions of a mechanical problem Wed, 31 May 2023 00:00:00 GMT http://hdl.handle.net/10256/23691 2023-05-31T00:00:00Z http://hdl.handle.net/10256/23689 Damage inception of composite under dynamic loadings Pernas-Sánchez, Jesús; Rodríguez-Sereno, J.M.; Artero Guerrero, José Alfonso; López-Puente, J.; Vaz-Romero Santero, Álvaro; Naya, F.; Varas, D.; Cohen, A.; Lukic, B.; Rack, A.; Levi-Hevroni, D. In this work a original work is presented in which the damage inception of notched composite laminates is analysed using Ultra-high speed radiography in combination of Ultra high speed video cameras. The unique facility at the ID19 of the European Sincotron Facility (ESRF), Split Hopkinson Pressure Bar (SHPB) and the Uc3m facilities has been used to perform the experimental campaign Wed, 31 May 2023 00:00:00 GMT http://hdl.handle.net/10256/23689 2023-05-31T00:00:00Z http://hdl.handle.net/10256/23688 Adhesively bonded joint shear test characterization using a modified arcan fixture Brearley, David; Lakrimi, M’hamed; Dulieu-Barton, Janice M.; Thomsen, Ole Thybo Adhesively bonded joints are frequently used for many composite engineering applications in eg. the aerospace, energy, civil, automotive [1] and medical sectors. This is because bonded joints display several advantages relative to other joints including improved stiffness and strength, reduced mass, ability to form continuous surfaces and ability to join dissimilar materials. However, depending on the joint geometry, bonded joints may not be as strong as joints made using other techniques, especially if a butt joint is required. In magnetic resonance imaging (MRI) machine magnets, butt joints are used between glass-fibre reinforced plastic (GFRP) rings and epoxy infused coils of superconducting wire. Because such joints are subjected to large electromagnetic biaxial forces induced by the magnetic fields they produce, it is important to understand the strength of such joints. Thus, a mechanical test method needs to be devised that can produce representative biaxial and uniaxial loads, and able to produce accurate failure envelopes that can be related to the complex stress states experienced by such adhesive joints Wed, 31 May 2023 00:00:00 GMT http://hdl.handle.net/10256/23688 2023-05-31T00:00:00Z http://hdl.handle.net/10256/23687 Fatigue cohesive zone modelling of a benchmark test for composites under complex loading sequences resulting in non-self-similar damage evolution Leciñana Arregui, Iñaki; Carreras Blasco, Laura; Renart Canalias, Jordi; Turon Travesa, Albert; Zurbitu González, Javier In this work, the fatigue CZM developed in C. G. Dávila (2020, April. NASA/TP–2020-220584) and the simulation strategy proposed in I. Lecinana (Engineering Fracture Mechanics, 2023, vol.286, art. num.109273) are adopted to simulate a novel fracture benchmark test that is considered as equivalent of in-service loading since it considers the transient effects of alternating different loading modes, monotonic, and fatigue loading. The case study was performed on a AS4D/PEKK-FC thermoplastic composite. Different combinations of loading modes, monotonic, and fatigue loading were applied. The non-self-similar damage evolution of different failure mechanisms such as brittle fracture, plastic deformation, and large-scale fibre bridging were correlated qualitatively to the different superposed cohesive laws, giving an insight on the phenomenological nature of superposing cohesive laws Wed, 31 May 2023 00:00:00 GMT http://hdl.handle.net/10256/23687 2023-05-31T00:00:00Z