Static Behaviours of Carbon Fibre Composite Strip with Bifurcated Type Shape Memory Alloy Pins

2007 ◽  
Vol 334-335 ◽  
pp. 1153-1156
Author(s):  
Kuen Cheong Chan ◽  
Li Min Zhou
Keyword(s):  
Shape Memory Alloy ◽  
Carbon Fibre ◽  
Shape Memory ◽  
Numerical Study ◽  
Fibre Composite ◽  
Axial Stress ◽  
Three Dimensional ◽  
Woven Fabric ◽  
Carbon Fibre Composite ◽  
Fabric Composite

A numerical study of the static behaviours of composite strip with bifurcated type shape memory alloy pins has been conducted. The case of bifurcated type shape memory alloy pins inserted inside the composite strip around the hole to reinforce the laminate, which was subjected to the axial stress was simulated. The models for stress analysis were established by using ANSYS finite element programme. Two types of shape memory alloy pins were proposed to insert along the through thickness direction of the carbon fibre woven fabric composite strip to induce the clamping force. The pre-tensioned load was applied to the shape memory alloy pins in order to reduce occurrence of delamination in the laminate. Three-dimensional elements and contact elements were used to simulate the contact between the composite laminate and shape memory alloy pin to investigate the stress distribution around the hole in the composite strip. The effect of pre-strain of shape memory alloy on the stresses inside composite was studied. The results show that the stress characteristics of the button-shaped and bifurcated shape memory alloy pin models are similar; however, the stresses for the button-shaped pin model are lower. The tensile and compressive stresses, both in button-shaped and bifurcated pin models, are strongly dependent on the percentage of pre-strain of the shape memory alloy. It is therefore concluded that the shape memory alloy pin method was significantly reduced the stress concentration of the composite strip laminate.

scholarly journals Precision Fibre Angle Inspection for Carbon Fibre Composite Structures Using Polarisation Vision

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2765
Author(s):  
Gary A. Atkinson ◽  
Sean O’Hara Nash ◽  
Lyndon N. Smith
Keyword(s):  
Carbon Fibre ◽  
Composite Structures ◽  
Fibre Composite ◽  
Three Dimensional ◽  
Dark Field ◽  
Carbon Fibre Composite ◽  
Material Type ◽  
Ambient Lighting ◽  
Dark Field Illumination ◽  
Planar Regions

This paper evaluates the precision of polarisation imaging technology for the inspection of carbon fibre composite components. Specifically, it assesses the feasibility of the technology for fibre orientation measurements based on the premise that light is polarised by reflection from such anisotropically conductive surfaces. A recently commercialised Sony IMX250MZR sensor is used for data capture by using various lighting conditions. The paper shows that it is possible to obtain sub-degree accuracy for cured and dry woven and unidirectional materials in ideal conditions, which comprised dark field illumination. Indeed, in ideal conditions, the average relative angles can be measured to an accuracy of 0.1–0.2°. The results also demonstrate a precision of the order 1° for more general illumination, such as dome illumination and ambient lighting, for certain material type/lens combinations. However, it is also shown that the precision varies considerably depending on illumination, lens choice and material type, with some results having errors above 2°. Finally, a feasibility study into the inspection of three-dimensional components suggests that only limited application is possible for non-planar regions without further research. Nevertheless, the observed phenomena for such components are, at least, qualitatively understood based on physics theory.

scholarly journals Design and Characterization of a Small-Scale Solar Sail Prototype by Integrating NiTi SMA and Carbon Fibre Composite

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Girolamo Costanza ◽  
Gabriele Leoncini ◽  
Fabrizio Quadrini ◽  
Maria Elisa Tata
Keyword(s):  
Carbon Fibre ◽  
Shape Memory ◽  
Fibre Composite ◽  
Weight Ratio ◽  
Solar Sail ◽  
Structure Design ◽  
Small Scale ◽  
Momentum Exchange ◽  
Carbon Fibre Composite ◽  
Solar Sails

Solar sails are propellantless systems where the propulsive force is given by the momentum exchange of reflecting photons. In this study, a self-deploying system based on NiTi shape memory wires and sheets has been designed and manufactured. A small-scale prototype of solar sail with carbon fibre loom has been developed. Different configurations have been tested to optimize material and structure design of the small-scale solar sail. In particular the attention has been focused on the surface/weight ratio and the deployment of the solar sail. By reducing weight and enlarging the surface, it is possible to obtain high values of characteristic acceleration that is one of the main parameters for a successful use of the solar sail as propulsion system. Thanks to the use of shape memory alloys for self-actuation of the system, complexity of the structure itself decreases. Moreover, sail deployment is simpler.

Carbon fibre composite development for in-ground UAV’s with NACA0012 aerofoil wing

2021 ◽  
Author(s):  
Ajanas Saludheen ◽  
Firaz Muhammed Zakariya ◽  
M Ankith ◽  
Nirmal Nandakumar ◽  
Jais George ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Fibre Composite ◽  
Carbon Fibre Composite

Design and Optimization of a Shape Memory Alloy-Based Self-Folding Sheet

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Edwin Peraza-Hernandez ◽  
Darren Hartl ◽  
Edgar Galvan ◽  
Richard Malak
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Three Dimensional ◽  
Building Blocks ◽  
Passive Layer ◽  
Von Mises Stress ◽  
Maximum Temperature ◽  
Radius Of Curvature ◽  
Folding Angle ◽  
The Impact

Origami engineering—the practice of creating useful three-dimensional structures through folding and fold-like operations on two-dimensional building-blocks—has the potential to impact several areas of design and manufacturing. In this article, we study a new concept for a self-folding system. It consists of an active, self-morphing laminate that includes two meshes of thermally-actuated shape memory alloy (SMA) wire separated by a compliant passive layer. The goal of this article is to analyze the folding behavior and examine key engineering tradeoffs associated with the proposed system. We consider the impact of several design variables including mesh wire thickness, mesh wire spacing, thickness of the insulating elastomer layer, and heating power. Response parameters of interest include effective folding angle, maximum von Mises stress in the SMA, maximum temperature in the SMA, maximum temperature in the elastomer, and radius of curvature at the fold line. We identify an optimized physical realization for maximizing folding capability under mechanical and thermal failure constraints. Furthermore, we conclude that the proposed self-folding system is capable of achieving folds of significant magnitude (as measured by the effective folding angle) as required to create useful 3D structures.

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