Design and Aerodynamic Characteristics Analysis of a Section Morphing Wing Based on Smart Materials

2013 ◽  
Vol 753-755 ◽  
pp. 1764-1767
Author(s):  
Yue Min Yu

This paper discusses the design of a section morphing wing that permits a change in the wing section while simultaneously supporting structural wing loads. Section morphing wing allows for two discreet airfoil of the wing. The airfoil 1 is original airfoil maintained by NACA 4412 rib sections. The section morphing wing uses shape memory alloy spring actuator to drive wing section deformation. Skins of the section morphing wing uses shape memory polymer. Computational aerodynamics are used to estimate the performance and dynamic characteristics of each wing section of this section morphing wing as its wing section is changed. Results show that when angle of attach (AOA) is 0 deg, the lift-drag ratio decrease as the airfoil thickness decreases when mach number is less than 0.9 and the lift-drag ratio increase as the airfoil thickness decreases when mach number is greater than 0.9. When AOA is 5deg, the lift-drag ratio increase as the airfoil thickness decreases . The lift-drag ratio decrease as the airfoil thickness decreases when mach number is less than 0.7. When AOA is 10deg, the lift-drag ratio increase as the airfoil thickness decreases when mach number is greater than 0.7. We can chose airfoil 1 or airfoil 2 according to variation flight conditions.

Author(s):  
L. Santo ◽  
L. Iorio ◽  
G. M. Tedde ◽  
F. Quadrini

Shape Memory Polymer Composites (SMPCs) are smart materials showing the structural properties of long-fiber polymer-matrix together with the functional behavior of shape memory polymers. In this study, SM carbon fiber reinforced (CFR) composites have been produced by using a SM interlayer between two CFR prepregs. Their SM properties have been evaluated in comparison with traditional structural CFR composites without the SM interlayer by using an especially designed test. Active and frozen forces are measured during a thermo-mechanical cycle in the three-point bending configuration. Experimental results show that SMPCs are able to fix a temporary deformed shape by freezing high stresses.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4246 ◽  
Author(s):  
Yujie Chen ◽  
Chi Chen ◽  
Hafeez Ur Rehman ◽  
Xu Zheng ◽  
Hua Li ◽  
...  

Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. Recently, significant achievements have been made in fabrication, modelling, and manipulation of SMP-based artificial muscles. This paper presents a review of the recent progress in shape-memory polymer-based artificial muscles. Here we focus on the mechanisms of SMPs, applications of SMPs as artificial muscles, and the challenges they face concerning actuation. While shape-memory behavior has been demonstrated in several stimulated environments, our focus is on thermal-, photo-, and electrical-actuated SMP artificial muscles.


2020 ◽  
Vol 31 (10) ◽  
pp. 1243-1283 ◽  
Author(s):  
Ebrahim Yarali ◽  
Ali Taheri ◽  
Mostafa Baghani

Shape memory polymers are a class of smart materials, which are capable of fixing their deformed shapes, and can return to their original shape in reaction to external stimulus such as heat. Also due to their exceptional properties, they are mostly used in four-dimensional printing applications. To model and investigate thermomechanical response of shape memory polymers mathematically, several constitutive equations have been developed over the past two decades. The purpose of this research is to provide an up-to-date review on structures, classifications, applications of shape memory polymers, and constitutive equations of thermally responsive shape memory polymers and their composites. First, a comprehensive review on the properties, structure, and classifications of shape memory polymers is conducted. Then, the proposed models in the literature are presented and discussed, which, particularly, are focused on the phase transition and thermo-viscoelastic approaches for conventional, two-way as well as multi-shape memory polymers. Then, a statistical analysis on constitutive relations of thermally activated shape memory polymers is carried out. Finally, we present a summary and give some concluding remarks, which could be helpful in selection of a suitable shape memory polymer constitutive model under a typical application.


Author(s):  
Fei Liang ◽  
Jihua Gou ◽  
He Shen ◽  
Yunjun Xu ◽  
Bob Mabbott

Shape memory polymers (SMPs) are one of the most popular smart materials due to light weight and high elastic deformation capability. In this study, highly conductive carbon nanofibers paper (CNFP) was coated on the surface of SMP as a conductive layer for electro actuation of SMP. To overcome the drawback of low modulus and low strength of shape memory polymer (SMP), continuous carbon fiber reinforcement was also incorporated with SMP by autoclave processing. The dynamic mechanical analysis (DMA) result showed over 600% increase of storage modulus of SMP by introducing carbon fiber reinforcement. Also, the shape recovery time of SMP has been reduced over 150%, while the recovery ratio of SMP has been improved to 99% by incorporating with carbon fiber reinforcement. Additionally, the mechanical property degradation of SMP composites has been investigated after different electro actuation cycles. After 50 actuation cycles, the decrease of flexural modulus of SMP composites is negligible (< 2%), and the ultimate flexural strength of SMP composites only decreased 25%. The SMP composite shows high strength and modulus, and good durability.


2013 ◽  
Vol 721 ◽  
pp. 169-172 ◽  
Author(s):  
Yu Gu ◽  
Shao Xiong Li

The viscoelastic behaviors of shape memory polymers have a significant influence on the function realization of this kind of smart materials. In this study, stress-strain hysteresis under uniaxial tension of epoxy shape memory polymers with varied curing agent contents and types were tested at different temperatures. The effects of the testing temperature, curing-agent type and content on the viscoelastic behaviors of the materials were discussed.


2011 ◽  
Vol 287-290 ◽  
pp. 2756-2759 ◽  
Author(s):  
Yi Jun Zhou ◽  
Fu Ling Guan ◽  
Li Feng Qian

In this paper, the advantages of smart materials and structures are introduced. Because of the influence of friction, it’s difficult to deploy the large ring truss antenna driving by cable. The SPMC hinge is added in the deployable joint, the deployable antenna is deployed by heating the material to cause recovery strain, which substitutes for the driving by cable. Describe the behavior of SPMC material, and do the simulation, from the analysis results, we can aim that the stress of SPMC satisfies the yielding stress when the node is furled. At the same time, the force to expand the antenna caused by heating SPMC is also obtained. Compared the different size of width, the variation of recovery force can be got.


2020 ◽  
pp. 002199832095817
Author(s):  
Ibrahim Goda ◽  
Zakariya Zubair ◽  
Gildas L’Hostis ◽  
Jean-Yves Drean

Shape memory polymer (SMP) composites are attractive and excellent smart materials due to their outstanding properties and rich functionality as they combine typical mechanical and functional properties of composites with shape memory properties. In particular, 3D reinforced preforms have tremendous potential for the development of functional composites by using the capabilities of 3D woven fabric preform design, and polymer shape memory behavior. Within that scope, this work aims to investigate the shape memory behavior and shape recovery properties of a specific type of 3D multilayer woven SMP composite in response to external stimuli. For this purpose, nine different multilayer stitched fabrics are produced with different weave structures, and different fabric thread densities using polyimide filaments. Then, a series of tests is carried out on these fabrics to evaluate their mechanical and physical properties. The layered fabric design that delivers high mechanical performance is next involved to manufacture the SMP composite samples, for which shape recovery capability is investigated. Fold-deploy and other shape memory cycle tests are performed to evaluate the shape memory characteristics. An optical 3D scanner based on fringe projection is further proposed to precisely acquire the geometry data and perform deformation analysis to quantitatively evaluate the shape fixity and shape recovery behaviors. The results from this study are very promising, demonstrating that these multilayer SMP structures can successfully be recovered following the desired design constraints without noticeable damage.


Author(s):  
Justin E. Manzo ◽  
Ephrahim Garcia

In order to maximize lift for use in turning and landing maneuvers, bats make use of continuous camber change along their fifth metacarpal more effectively than all modern-day aircraft flaps. This biological shape change produces lower drag than modern aircraft, allowing for greater flight efficiency and lower noise signatures. A mechanism to replicate this demands a seamless actuator to avoid gaps and discontinuities, and requires the use of morphing structures. However, a recurring problem in morphing aircraft design is inefficiency of both space and power consumption. Problems often stem from the replacement of rigid structural elements with actuator elements that must be powered in order to carry static loads. To resolve this issue, a ‘smart joint’ concept is proposed which allows rigidity in its passive state, and becomes compliant while serving as an actuator by way of a composite of smart materials. Using a network of shape memory alloy and shape memory polymer, the joint is capable of rotations on the order of 5 percent camber over an arbitrary length when placed along a skeletal element of a bat-like wing structure. An analytical model is used to predict the behavior of the joint as a function of resistive heating and external loading, and is used to examine the layer thicknesses and locations (i.e. bimorph vs. unimorph) and placement of rigid elastic members in order to maximize deflection under a given load. Validation of the joint using is conducted via finite element modeling, and expected airfoil data for a generic shape maneuver to be accomplished by this joint is shown.


2010 ◽  
Vol 24 (15n16) ◽  
pp. 2351-2356 ◽  
Author(s):  
YAN-JU LIU ◽  
XIN LAN ◽  
HAI-BAO LU ◽  
JIN-SONG LENG

Smart materials can be defined as materials that sense and react to environmental conditions or stimuli. In recent years, a wide range of novel smart materials have been developed in biomaterials, sensors, actuators, etc. Their applications cover aerospace, automobile, telecommunications, etc. This paper presents some recent progresses in polymeric smart materials. Special emphasis is laid upon electroactive polymer (EAP), shape memory polymer (SMP) and their composites. For the electroactive polymer, an analysis of stability of dielectric elastomer using strain energy function is derived, and one type of electroactive polymer actuator is presented. For the shape memory polymer, a new method is developed to use infrared laser to actuate the SMP through the optical fiber embedded within the SMP. Electrically conductive nanocarbon powders are utilized as the fillers to improve the electrical conductivity of polymer. A series of fundamental investigations of electroactive SMP are performed and the shape recovery is demonstrated.


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