Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 150270

150270 - Mechanics of Scale-Covered Plate Under Bending Deformation 

Biomimetic scale-covered systems exhibit remarkable potential across various advanced applications, notably in fields such as soft robotics, protective armor, wearable materials, and multifunctional aerospace structures. These systems typically consist of stiff, rectangular plate-like scales embedded within a softer substrate, arranged in a periodic pattern. Experimental observations have highlighted a pronounced nonlinear strain stiffening behavior in these systems, even when the underlying substrate experiences only minimal strains. However, accurately capturing this complex behavior using commercial finite element (FE) softwares has been challenging due to the multiple sliding contacts that occur between the scales post-engagement. Consequently, there is a pressing need for precise and reliable analytical models to elucidate the architecture-property relationships for effective analysis and design. This work investigates the intricate contact kinematics and mechanics of biomimetic scale-covered plates subjected to bi-directional bending. The investigation encompasses both synclastic (curvature in the same direction) and anticlastic (curvature in opposite directions) deformations of the plate. By employing the work-energy balance principle, mechanical moment-curvature relationships are derived to provide a detailed understanding of these systems. The findings reveal that when a plate is bent to a specific curvature, a quasi-rigid locked state emerges for both synclastic and anticlastic curvatures. Notably, in the case of anticlastic bending, the curvature at which this locking occurs closely matches that of a beam with equivalent geometry and configuration. However, for synclastic bending, the locking occurs significantly earlier due to the influence of cross-curvature effects. This early locking in synclastic bending underscores the complex interplay of curvatures in these systems. Furthermore, the moment-curvature relationships demonstrate a pronounced anisotropic behavior in the plate, with the anisotropy being strongly influenced by the deformation state. The scale arrangement parameters, particularly the lattice geometry, play a crucial role in shaping the nonlinear behavior and the onset of the locked state. The findings also indicate potential for tuning the mechanical response of these systems through strategic design of scale geometry and arrangement. The analytical models developed in this study have been rigorously compared with equivalent finite element analyses for validation in selected cases, yielding excellent agreement. The outcomes of this research significantly enhance the understanding of the nonlinear and anisotropic behavior of scale-covered plate systems. This improved understanding paves the way for systematic design and integration of these systems tailored for specific applications, thereby broadening their potential utility in advanced engineering fields. Future work could explore the dynamic response and interactions with external environments to further expand the applicability of these innovative materials.

Presenting Author: Pranta Rahman Sarkar University of Central Florida

Presenting Author Biography: Pranta is currently a Ph.D. student at the University of Central Florida, having joined the program in Fall 2022. He completed his B.Sc. at the Bangladesh University of Engineering and Technology. His research focuses on solid mechanics, computational mechanics, metamaterials, and composite materials. Currently, he is working on several NSF-funded projects involving biomimetic scale-covered materials. In his leisure time, he enjoys sleeping and watching cricket.

Authors:

Pranta Rahman Sarkar University of Central Florida
Hossein Ebrahimi University of Central Florida
Md Shahjahan Hossain University of Central Florida
Hessein Ali Stress Engineering Services, Inc.
Ranajay Ghosh University of Central Florida