An electric‐driven variable stiffness morphing skin: Preparation and properties

2022 ◽  
Author(s):  
Xiaoming Ren ◽  
Guangming Zhu
Keyword(s):  
Variable Stiffness ◽  
Skin Preparation

A variable stiffness morphing skin: preparation and properties

2021 ◽  
Author(s):  
Xiaoming Ren ◽  
Guangming Zhu
Keyword(s):  
Molecular Weight ◽  
Shape Memory ◽  
Mass Fraction ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Variable Stiffness ◽  
Promising Candidate ◽  
Skin Preparation ◽  
Out Of Plane ◽  
Shape Fixity

Abstract In the course of flight, morphing skins play an important role in morphing aircrafts. Shape memory polymer (SMP) with variable stiffness performance is a good candidate material for skin. In this paper, a series of SMP morphing skins were prepared from hydro-epoxy resin (HEP), carboxyl-terminated butadiene acrylonitrile (CTBN) and maleic anhydride (MA). By adjusting molecular weight and content of CTBN, in-plane properties and out-of-plane properties of morphing skins can be adjusted. Due to the in-plane tensile stress acting on the skin during flight, tensile test was carried out to study its in-plane performance. After testing, skin can resist maximum in-plane tensile strength of 63.7 MPa. As for the out-of-plane performance of the skin, shape memory test was studied in this paper. All morphing skins have 100% shape fixity rate (Rf) and fast shape recovery rate (Rr). When toughened by CTBN of 10% of 4000 molecular weight with a mass fraction, the skin can recover its out-of-plane deformed shape in 33s. The SMP skins were proved to be a promising candidate for morphing skins.

Design of Variable Stiffness Cylinder with Holes Under Bending for Maximum Buckling Load Using Lamination Parameters

2019 ◽  
Author(s):  
Mazen Albazzan ◽  
Brian Tatting ◽  
Ramy Harik ◽  
Zafer Gürdal ◽  
Adriana Blom-Schieber ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Buckling Load ◽  
Lamination Parameters

Design of a Variable Stiffness Spar

1997 ◽  
Author(s):  
Sridhar Kota ◽  
Joel Hetrick ◽  
Laxman Saggere
Keyword(s):  
Variable Stiffness

scholarly journals A Variable Parameter Ambient Vibration Control Method Based on Quasi-Zero Stiffness in Robotic Drilling Systems

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 67
Author(s):  
Laixi Zhang ◽  
Chenming Zhao ◽  
Feng Qian ◽  
Jaspreet Singh Dhupia ◽  
Mingliang Wu
Keyword(s):  
Vibration Control ◽  
Vibration Isolation ◽  
Control Method ◽  
Control Strategies ◽  
Equations Of Motion ◽  
Variable Parameter ◽  
Harmonic Balance Method ◽  
Variable Stiffness ◽  
Ambient Vibration ◽  
Robotic Drilling

Vibrations in the aircraft assembly building will affect the precision of the robotic drilling system. A variable stiffness and damping semiactive vibration control mechanism with quasi-zero stiffness characteristics is developed. The quasi-zero stiffness of the mechanism is realized by the parallel connection of four vertically arranged bearing springs and two symmetrical horizontally arranged negative stiffness elements. Firstly, the quasi-zero stiffness parameters of the mechanism at the static equilibrium position are obtained through analysis. Secondly, the harmonic balance method is used to deal with the differential equations of motion. The effects of every parameter on the displacement transmissibility are analyzed, and the variable parameter control strategies are proposed. Finally, the system responses of the passive and semiactive vibration isolation mechanisms to the segmental variable frequency excitations are compared through virtual prototype experiments. The results show that the frequency range of vibration isolation is widened, and the stability of the vibration control system is effectively improved without resonance through the semiactive vibration control method. It is of innovative significance for ambient vibration control in robotic drilling systems.

scholarly journals Design of a Variable-Stiffness Compliant Skin for a Morphing Leading Edge

2021 ◽  
Vol 11 (7) ◽  
pp. 3165
Author(s):  
Zhigang Wang ◽  
Yu Yang
Keyword(s):  
Composite Laminate ◽  
Large Scale ◽  
Design Method ◽  
Leading Edge ◽  
Variable Stiffness ◽  
Manufacturing Constraints ◽  
Aircraft Wing ◽  
Noise Abatement ◽  
Civil Aircraft ◽  
Final Profile

A seamless and smooth morphing leading edge has remarkable potential for noise abatement and drag reduction of civil aircraft. Variable-stiffness compliant skin based on tailored composite laminate is a concept with great potential for morphing leading edge, but the currently proposed methods have difficulty in taking the manufacturing constraints or layup sequence into account during the optimization process. This paper proposes an innovative two-step design method for a variable-stiffness compliant skin of a morphing leading edge, which includes layup optimization and layup adjustment. The combination of these two steps can not only improve the deformation accuracy of the final profile of the compliant skin but also easily and effectively determine the layup sequence of the composite layup. With the design framework, an optimization model is created for a variable-stiffness compliant skin, and an adjustment method for its layups is presented. Finally, the deformed profiles between the directly optimized layups and the adjusted ones are compared to verify its morphing ability and accuracy. The final results demonstrate that the obtained deforming ability and accuracy are suitable for a large-scale aircraft wing.

Burgers viscoelastic model-based variable stiffness design of compliant clamping mechanism for leafy greens harvesting

2021 ◽  
Vol 208 ◽  
pp. 1-15
Author(s):  
Liangliang Zou ◽  
Jin Yuan ◽  
Xuemei Liu ◽  
Jinguang Li ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Viscoelastic Model ◽  
Variable Stiffness ◽  
Leafy Greens ◽  
Model Based ◽  
Stiffness Design
Sign in / Sign up

Export Citation Format

Share Document