scholarly journals Strength Prediction and Experimental Validation of Adhesive Joints Including Polyethylene, Carbon-Epoxy and Aluminium Adherends

2010 ◽  
Vol 636-637 ◽  
pp. 1157-1164 ◽  
Author(s):  
A.M.G. Pinto ◽  
A.G. Magalhães ◽  
Raul D.S.G. Campilho ◽  
Marcelo F.S.F. de Moura ◽  
A.P.M. Baptista
Keyword(s):  
Chromic Acid ◽  
Damage Model ◽  
Surface Preparation ◽  
Numerical Results ◽  
Reinforced Plastic ◽  
Special Surface ◽  
Carbon Fibre Reinforced Plastic ◽  
Inert Surfaces ◽  
Cohesive Damage ◽  
Good Agreement

Polyolefins are especially difficult to bond due to their non-polar, non-porous and chemically inert surfaces. Acrylic adhesives used in industry are particularly suited to bond these materials, including many grades of polypropylene (PP) and polyethylene (PE), without special surface preparation. In this work, the tensile strength of single-lap PE and mixed joints bonded with an acrylic adhesive was investigated. The mixed joints included PE with aluminium (AL) or carbon fibre reinforced plastic (CFRP) substrates. The PE substrates were only cleaned with isopropanol, which assured cohesive failures. For the PE CFRP joints, three different surfaces preparations were employed for the CFRP substrates: cleaning with acetone, abrasion with 100 grit sand paper and peel-ply finishing. In the PE AL joints, the AL bonding surfaces were prepared by the following methods: cleaning with acetone, abrasion with 180 and 320 grit sand papers, grit blasting and chemical etching with chromic acid. After abrasion of the CFRP and AL substrates, the surfaces were always cleaned with acetone. The tensile strengths were compared with numerical results from ABAQUS® and a mixed mode (I+II) cohesive damage model. A good agreement was found between the experimental and numerical results, except for the PE AL joints, since the AL surface treatments were not found to be effective.

Evaluation of Water Flow on Interfacial Strength in PSA Film Delamination

2021 ◽  
Author(s):  
Kazuaki Inaba ◽  
Ibuki Mashio
Keyword(s):  
Thin Film ◽  
Water Flow ◽  
Damage Model ◽  
Interfacial Strength ◽  
Crystalline Lens ◽  
Element Analysis ◽  
Significant Difference ◽  
Energy Release Rates ◽  
Cohesive Damage ◽  
Good Agreement

Abstract To model the peeling phenomenon during cataract surgery and examine the effect of fluid flow during surgery, we constructed a simplified physical system and compared the case where only static pressure is applied to the adhesive thin film and the case where water flow is applied to the film by suction. From experiments with and without suctioning, the energy release rates of the adhesive thin film were calculated to be approximately 10 N/m, and no significant difference was confirmed with or without suction. We modeled the peeling phenomenon using the cohesive damage model and performed a finite element analysis considering the coupling of the fluid and membrane. The simulation results without suction were in good agreement with the theoretical values of the stress and deflection. When the water flow was applied to collide with the peeling part, the film deflection at the center became smaller, and the radial and circumferential stresses became smaller. From this result, it is shown that the stress acting on the membrane surrounding the crystalline lens can be reduced and peeling can be performed by successfully using the water flow for peeling.

A Mixed Damage Model for Simulating Delamination of Composite T-Joint Components

2012 ◽  
Author(s):  
J. Chen
Keyword(s):  
Damage Model ◽  
Damage Effect ◽  
Damage Analysis ◽  
Test Results ◽  
Load Prediction ◽  
Damage Propagation ◽  
Cohesive Damage ◽  
Final Crack ◽  
Softening Stage ◽  
Good Agreement

A mixed cohesive damage model was introduced in this paper to study the delamination of composite T-joint components under pulling load. Prediction together with part of test results was presented in this paper. Modelling prediction had a good agreement with experimental work. This study indicated that the mixed damage scale plays an important role in the progressive damage analysis of T-joint components. The mixed damage scale properly reflected the effects of interaction between different damage modes in simulating damage propagation of an object with strong coupled effects. This coupled damage effect was considered from the material softening stage to final crack. Thus a proper damage accumulation was accounted since materials begin damage. An example given in this paper shown the delamination in the deltoid region of T-joint was simulated very well. Finally, a concept of novel materials was proposed for the deltoid region of T-joint in this paper. Initial investigation by simulating delamination presented that the damage resilience of composite T-joint with novel composite materials in deltoid region significantly improved its damage resilience.

scholarly journals Analysis and Design of a Leading Edge with Morphing Capabilities for the Wing of a Regional Aircraft—Gapless Chord- and Camber-Increase for High-Lift Performance

2021 ◽  
Vol 11 (6) ◽  
pp. 2752
Author(s):  
Conchin Contell Asins ◽  
Volker Landersheim ◽  
Dominik Laveuve ◽  
Seiji Adachi ◽  
Michael May ◽  
...  
Keyword(s):  
Leading Edge ◽  
Bird Strike ◽  
High Lift ◽  
Analysis And Design ◽  
Actuation System ◽  
Aerodynamic Properties ◽  
Reinforced Plastic ◽  
Stall Angle ◽  
Carbon Fibre Reinforced Plastic ◽  
Electromechanical Actuation

In order to contribute to achieving noise and emission reduction goals, Fraunhofer and Airbus deal with the development of a morphing leading edge (MLE) as a high lift device for aircraft. Within the European research program “Clean Sky 2”, a morphing leading edge with gapless chord- and camber-increase for high-lift performance was developed. The MLE is able to morph into two different aerofoils—one for cruise and one for take-off/landing, the latter increasing lift and stall angle over the former. The shape flexibility is realised by a carbon fibre reinforced plastic (CFRP) skin optimised for bending and a sliding contact at the bottom. The material is selected in terms of type, thickness, and lay-up including ply-wise fibre orientation based on numerical simulation and material tests. The MLE is driven by an internal electromechanical actuation system. Load introduction into the skin is realised by span-wise stringers, which require specific stiffness and thermal expansion properties for this task. To avoid the penetration of a bird into the front spar of the wing in case of bird strike, a bird strike protection structure is proposed and analysed. In this paper, the designed MLE including aerodynamic properties, composite skin structure, actuation system, and bird strike behaviour is described and analysed.

Impact and Damage Localisation of Carbon-Fibre-Reinforced Plastic Plates

PAMM ◽  
2011 ◽  
Vol 11 (1) ◽  
pp. 639-640 ◽  
Author(s):  
Andy Ungethuem ◽  
Rolf Lammering
Keyword(s):  
Carbon Fibre ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic

Point Contact Current Voltage Measurements of 4H-SiC Samples with Different Doping Profiles

2017 ◽  
Vol 897 ◽  
pp. 287-290 ◽  
Author(s):  
Matthias Kocher ◽  
Michael Niebauer ◽  
Mathias Rommel ◽  
Volker Haeublein ◽  
Anton J. Bauer
Keyword(s):  
Epitaxial Layer ◽  
Depth Profile ◽  
Point Contact ◽  
Surface Preparation ◽  
Epitaxial Layers ◽  
Depth Profiles ◽  
Current Voltage ◽  
Measured Resistance ◽  
Doping Profiles ◽  
Good Agreement

Point contact current voltage (PCIV) measurements were performed on 4H-SiC samples, both for n- an p-doped epitaxial layers as well as samples with rather shallow doping profiles realized by N- or Al-implantation in a range from 1016 cm-3 to 1019 cm-3. Surface preparation and measurement parameters were investigated in order to determine their influence on the measured resistance profiles. Furthermore depth profile measurements were performed on both an epitaxial layer as well as on implanted samples. These depth profiles could be measured reproducibly and showed good agreement with expected profiles for Al-implanted samples as well as for epitaxial layer whereas for N-implanted samples deviations between measured and expected profiles could be observed. It could be proven that PCIV profiling technique is a promising method for characterizing doped profiles in 4H-SiC, especially on Al-implanted samples.

On Wall Effects in Cavity Flows

1984 ◽  
Vol 28 (01) ◽  
pp. 70-75
Author(s):  
C. C. Hsu
Keyword(s):  
Numerical Results ◽  
Cavity Flows ◽  
Two Dimensional ◽  
Wall Effects ◽  
Free Jet ◽  
Theoretical Predictions ◽  
Experimental Findings ◽  
Good Agreement

Simple wall correction rules for two-dimensional and nearly two-dimensional cavity flows in closed or free jet water tunnels, based on existing linearized analyses, are made. Numerical results calculated from these expressions are compared with existing experimental findings. The present theoretical predictions are, in general, in good agreement with data.

Periodic wave solution of the Kundu-Mukherjee-Naskar equation in birefringent fibers via the Hamiltonian-based algorithm

2021 ◽  
Author(s):  
Kang-Jia Wang ◽  
Hong-Wei Zhu
Keyword(s):  
Wave Solution ◽  
Bright Light ◽  
Periodic Wave ◽  
Optical Soliton ◽  
Numerical Results ◽  
Periodic Wave Solution ◽  
Soliton Dynamics ◽  
Good Agreement

Abstract The Kundu-Mukherjee-Naskar equation can be used to address certain optical soliton dynamics in the (2+1) dimensions. In this paper, we aim to find its periodic wave solution by the Hamiltonian-based algorithm. Compared with the existing results, they have a good agreement, which strongly proves the correctness of the proposed method. Finally, the numerical results are presented in the form of 3-D and 2-D plots. The results in this work are expected to shed a bright light on the study of the periodic wave solution in physics.

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