scholarly journals Modeling of a cracked and repaired Al 2024T3 aircraft plate: effect of the composite patch shape on the repair performance

2019 ◽  
Vol 13 (50) ◽  
pp. 68-85
Author(s):  
Mohammed Baghdadi ◽  
Boualem Serier ◽  
Mokadem Salem ◽  
Bouchra Zaoui ◽  
Khacem Kaddouri
Keyword(s):  
Patch Shape ◽  
Composite Patch

A topological optimization algorithm applied to the design of composites patch repair of mixed-mode cracked plate

2017 ◽  
Vol 52 (17) ◽  
pp. 2387-2395 ◽  
Author(s):  
Matías Braun ◽  
Edgardo Ignacio Villa ◽  
Helio Riojas-Roldán ◽  
Claudio Guillermo Rocco
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Optimization Algorithm ◽  
Mixed Mode ◽  
Topological Optimization ◽  
Patch Repair ◽  
Finite Element Code ◽  
Patch Shape ◽  
Composite Patch ◽  
Iterative Analysis

In this work, a topology optimization algorithm is developed and implemented to get an optimum composite patch shape. Typically, the design process consists of an iterative analysis, where the best solution is obtained from a comparative study. In this way, we propose a topology optimization algorithm applied to obtain the optimum composite patch shape. The algorithm is implemented in MatLab, and uses the commercial finite element code Abaqus/Standard. A numerical example is analysed to show the capability of the proposed method. The obtained results are compared with numerical results reported by other researchers, revealing the potential of the developed algorithm.

scholarly journals Initiated Chemical Vapor Deposition (iCVD) Functionalized Polylactic Acid–Marine Algae Composite Patch for Bone Tissue Engineering

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 186
Author(s):  
Wiebke Reichstein ◽  
Levke Sommer ◽  
Salih Veziroglu ◽  
Selin Sayin ◽  
Stefan Schröder ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Chemical Vapor Deposition ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Vapor Deposition ◽  
Marine Algae ◽  
Chemical Vapor ◽  
Human Osteoblasts ◽  
Composite Patch ◽  
Initiated Chemical Vapor Deposition

The current study aimed to describe the fabrication of a composite patch by incorporating marine algae powders (MAPs) into poly-lactic acid (PLA) for bone tissue engineering. The prepared composite patch was functionalized with the co-polymer, poly (2-hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) (p(HEMA-co-EGDMA)) via initiated chemical vapor deposition (iCVD) to improve its wettability and overall biocompatibility. The iCVD functionalized MAP–PLA composite patch showed superior cell interaction of human osteoblasts. Following the surface functionalization by p(HEMA-co-EGDMA) via the iCVD technique, a highly hydrophilic patch was achieved without tailoring any morphological and structural properties. Moreover, the iCVD modified composite patch exhibited ideal cell adhesion for human osteoblasts, thus making the proposed patch suitable for potential biomedical applications including bone tissue engineering, especially in the fields of dentistry and orthopedy.

scholarly journals Fatigue Life Improvement of Cracked Aluminum 6061-T6 Plates Repaired by Composite Patches

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1421
Author(s):  
Armin Yousefi ◽  
Saman Jolaiy ◽  
Reza Hedayati ◽  
Ahmad Serjouei ◽  
Mahdi Bodaghi
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Weight Ratio ◽  
High Strength ◽  
Plastic Strain Amplitude ◽  
Composite Patch ◽  
Life Improvement ◽  
Cracked Structures ◽  
Aluminum Plates ◽  
High Flexibility

Bonded patches are widely used in several industry sectors for repairing damaged plates, cracks in metallic structures, and reinforcement of damaged structures. Composite patches have optimal properties such as high strength-to-weight ratio, easiness in being applied, and high flexibility. Due to recent rapid growth in the aerospace industry, analyses of adhesively bonded patches applicable to repairing cracked structures have become of great significance. In the present study, the fatigue behavior of the aluminum alloy, repaired by a double-sided glass/epoxy composite patch, is studied numerically. More specifically, the effect of applying a double-sided composite patch on the fatigue life improvement of a damaged aluminum 6061-T6 is analyzed. 3D finite element numerical modeling is performed to analyze the fatigue performance of both repaired and unrepaired aluminum plates using the Abaqus package. To determine the fatigue life of the aluminum 6061-T6 plate, first, the hysteresis loop is determined, and afterward, the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted and validated against the available experimental data from the literature. Results reveal that composite patches increase the fatigue life of cracked structures significantly, ranging from 55% to 100% for different applied stresses.

Development of smart bonded composite patch repair solution

2020 ◽  
Author(s):  
Florian Lambinet ◽  
Zahra Sharif Khodaei
Keyword(s):  
Patch Repair ◽  
Composite Patch ◽  
Bonded Composite

Resizable Ventricular Patch Plasty in the Porcine Left Ventricle a Pilot Study

2010 ◽  
Vol 5 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Willemijn H. F. Huijgen ◽  
Paul F. Gründeman ◽  
Tycho van der Spoel ◽  
Maarten-Jan Cramer ◽  
Paul Steendijk ◽  
...  
Keyword(s):  
Pilot Study ◽  
Animal Experiments ◽  
Ventricular Volume ◽  
Left Ventricular ◽  
Left Ventricular Aneurysm ◽  
Patch Shape ◽  
End Diastolic Volume ◽  
Patch Plasty

Objective Endoventricular circular patch plasty is a method used to reconstruct the ventricular cavity in patients with (post) ischemic left ventricular aneurysm or global dilatation. However, late redilatation with mitral regurgitation has been reported, in which postoperative apex shape seems to play an important role. We studied the feasibility of ventricular volume downsizing with a variably shaped patch in porcine hearts. Methods In five in vitro and two acute animal experiments, a dyskinetic aneurysm was simulated with a pericardial insert. Reducing patch surface by changing patch shape diminished end-diastolic volume. In vitro, static end-diastolic volume was determined for each patch shape using volumetry and echocardiography. In the acute animal experiments, preliminary observations of patch behavior in live material were made, and pressure/time relationship, dPdTmax, was registered. Results In vitro, bringing the convex patch into a flat plane reduced LV volume from 66 ± 7 mL (aneurysm) to 49 ± 5 mL. Four of 5 patch shapes further reduced volume to a mean of 38 ± 7 mL (P = 0.03). The in vitro echocardiographic measurements correlated with volumetry findings (r = 0.81). In the acute animal experiments, dPdTmax varied with patch shape, independent of volume changes. Conclusions In this pilot study, in vitro shape configuration of the resizable ventricular patch resulted in a calibrated end-diastolic volume reduction. The data of the two in vivo pilot experiments clearly indicate that change in patch configuration in the situation of more or less unchanged end-diastolic volume had impact on cardiac performance. Future studies must substantiate the results of this observation.

A new method for repairing aircraft structures containing aluminum alloy 2024-T3 using a combination of composite patch and bolt clamping

2018 ◽  
Vol 52 (30) ◽  
pp. 4203-4218 ◽  
Author(s):  
HN Maleki ◽  
TN Chakherlou
Keyword(s):  
Tensile Strength ◽  
Hybrid Method ◽  
Mixed Mode ◽  
Structural Integrity ◽  
Pure Shear ◽  
Shear Mode ◽  
Mixed Mode Fracture ◽  
Aircraft Structures ◽  
Repair Method ◽  
Composite Patch

Aircraft repair is gaining importance for extending the service life of aging aircraft and also for improving its structural integrity. In this paper, a new repair method of aircraft structures is presented, and the performance of this method in mixed mode fracture has been evaluated and compared with other two repair methods by conducting experimental and numerical investigations. To do so, four batches of specimens were prepared and each of them subjected to five level of mixed mode loading using a modified version of Arcan fixture. Further, finite element simulations were utilized to find stress intensity factors to explain the experimental test results. The experimental results indicate that the hybrid repair method is the most effective method in terms of increasing fracture load and it was observed a significant increase in the tensile strength of the repaired parts by all three methods compared to the simple cracked samples. Repaired samples with the hybrid method, composite patch and bolt clamping exhibited up to 49%, 44%, and 24% increase in tensile strength under pure tensile mode respectively. However, in pure shear mode, the fracture strength increased to 28%, 18%, and 9% by the hybrid method, bolt clamping and composite patch respectively.

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