Authors :
B SHATINDRA; SAGAR V NAVALGUND; TEJAS C C; ROHITH V CHINDI; Dr. Hareesha N.G
Volume/Issue :
Volume 9 - 2024, Issue 5 - May
Google Scholar :
https://tinyurl.com/48ddp3t4
Scribd :
https://tinyurl.com/bdz62dyw
DOI :
https://doi.org/10.38124/ijisrt/IJISRT24MAY1201
Abstract :
Cellular materials exhibit two key properties: structures and mechanisms. This allows for the design of structures using
cellular materials while effectively controlling both stiffness and flexibility, based on the connectivity of the struts. This study
aims to explore the in-plane flexible properties of cellular materials dominated by bending under macroscopic deformation.
Additionally, it seeks to establish a method for designing a passive morphing airfoil with flexible cellular cores. The
investigation focuses on airfoils featuring re-entrant and S-shaped cellular cores, analyzing their behavior under static loads
by examining the deformation of the cellular cores subjected to aerostatic loads. In the context of the airfoil's deformation
with flexible cellular cores under aerostatic loading, shear emerges as the predominant deformation mode for the
cores of the airfoil. Wings of conventional aircraft are optimized for only a few conditions, not for the entire flight envelope.
Therefore, it is necessary to develop the morphing airfoil with smart structures for the next generation of excellent aircraft.
In this project, this was made possible using, re-entrant and S-shaped auxetic structures as a member of the meta-
material family, with negative Poisson's ratio to enable an effortless passive morphing mechanism as it has high flexibility
along in-plane direction (chord-wise). The 3D CAD Models of Re-entrant and S-shaped auxetic airframes were designed
and analyzed. Initially, Static Structural analysis is performed on both airframes to observe the structure’s behavior, and
design modification and optimization are performed in different iterations. With a reduction in maximum equivalent stress
by 20%, the Re-entrant airframe exhibits lower stress and hence more flexibility. The wings were modeled with a span of
1m using auxetic airframes, air pressure was generated using CFD analysis with MACH 0.45. Finally, the fluid-structure
interaction was done by importing the air pressure and performing static structural analysis for the structural performance
of wings using auxetic airframes. It was found that Re-entrant auxetic wing showed an increase of 9.99% in load carrying
capacity, accompanied by a decrease of 389 grams of weight when compared to S-shaped auxetic wing.
Considering the deformation of the airframe with flexible cellular cores under a load, the re-entrant honeycomb core
shows the highest flexibility in shear and causes lower stress than the S-auxetic cores. This implies that the re-entrant
honeycomb core has the potential for passive morphing.
References :
- S. Sivambika, Benitha Shalom, Darsha Reddy K, Vignesh S, Aircraft Wing Morphing using Auxetic structure to control flutter, 2023.
- P R Budarapu, Sudhir Sastry Y B, R NATARAJAN, Design concepts of an aircraft wing: composite and morphing airfoil with auxetic structures, Frontiers of Structural and Civil Engineering. 10 (2016) 394–408, http://dx.doi.org/10.1007/s11709-016-0352-z.
- Hyeonu Heo, Jaehyung Ju, Doo-Man Kim, Compliant cellular structures: Application to a passive morphing airfoil, Elsevier. Comp. str. 106 (2013) 560-569, https://doi.org/10.1016/j.compstruct.2013.07.013.
- Paolo Bettini et.al, Composite chiral structures for morphing airfoils: Numerical analyses and development of a manufacturing process, Elsevier. Comp: Part B 41 (2010) 133-147, https://doi.org/10.1016/j.compositesb.2009.10.005.
- A Alderson and K L Alderson, Auxetic materials, The University of Bolton, UK, https://doi.org/10.1243/09544100JAERO185.
- Avinash Mohan & Prasanna Mondal, Impact Behavior of Auxetic Structures: Experimental and Numerical Analysis”, Elsevier. Mater Tod 87 (2023) 292-298, https://doi.org/10.1016/j.matpr.2023.05.631.
- Kusum Meena & Sarat Singamneni, A New Auxetic Structure with Significantly Reduced Stress, Elsevier. Mater & Des 173 (2019) 107779, https://doi.org/10.1016/j.matdes.2019.107779.
- Zeyao Chen & Jianwang Shao, Concepts for Morphing Airfoil Using Novel Auxetic Lattices, ResearchGate. (2020), http://dx.doi.org/10.1007/978-981-15-1773-0_20.
- Krishna Prasath Logakannan, Velmurugan Ramachandran, Jayaganthan Rengaswamy & Dong Ruan, Dynamic Performance of a 3D Re-entrant Structure, Elsevier. Mech of Mater 148 (2020) 103503, https://doi.org/10.1016/j.mechmat.2020.103503.
Cellular materials exhibit two key properties: structures and mechanisms. This allows for the design of structures using
cellular materials while effectively controlling both stiffness and flexibility, based on the connectivity of the struts. This study
aims to explore the in-plane flexible properties of cellular materials dominated by bending under macroscopic deformation.
Additionally, it seeks to establish a method for designing a passive morphing airfoil with flexible cellular cores. The
investigation focuses on airfoils featuring re-entrant and S-shaped cellular cores, analyzing their behavior under static loads
by examining the deformation of the cellular cores subjected to aerostatic loads. In the context of the airfoil's deformation
with flexible cellular cores under aerostatic loading, shear emerges as the predominant deformation mode for the
cores of the airfoil. Wings of conventional aircraft are optimized for only a few conditions, not for the entire flight envelope.
Therefore, it is necessary to develop the morphing airfoil with smart structures for the next generation of excellent aircraft.
In this project, this was made possible using, re-entrant and S-shaped auxetic structures as a member of the meta-
material family, with negative Poisson's ratio to enable an effortless passive morphing mechanism as it has high flexibility
along in-plane direction (chord-wise). The 3D CAD Models of Re-entrant and S-shaped auxetic airframes were designed
and analyzed. Initially, Static Structural analysis is performed on both airframes to observe the structure’s behavior, and
design modification and optimization are performed in different iterations. With a reduction in maximum equivalent stress
by 20%, the Re-entrant airframe exhibits lower stress and hence more flexibility. The wings were modeled with a span of
1m using auxetic airframes, air pressure was generated using CFD analysis with MACH 0.45. Finally, the fluid-structure
interaction was done by importing the air pressure and performing static structural analysis for the structural performance
of wings using auxetic airframes. It was found that Re-entrant auxetic wing showed an increase of 9.99% in load carrying
capacity, accompanied by a decrease of 389 grams of weight when compared to S-shaped auxetic wing.
Considering the deformation of the airframe with flexible cellular cores under a load, the re-entrant honeycomb core
shows the highest flexibility in shear and causes lower stress than the S-auxetic cores. This implies that the re-entrant
honeycomb core has the potential for passive morphing.