1 |
Bending Mechanics of Bio-mimetic Stiff Scale-Covered PlateSarkar, Pranta Rahman 01 January 2024 (has links) (PDF)
Biomimetic scale-covered systems offer immense potential and applications, particularly in soft robotics, protective armors, wearable materials, and multifunctional aerospace structures. A typical system consists of stiff rectangular plate like scales embedded in a softer media and arranged periodically. Experimentally, these systems indicate pronounced nonlinear strain stiffening behavior even when the underlying substrate strains are small. However, capturing these behaviors using commercial finite element (FE) codes has proved difficult due to multiple sliding contacts between the scales after engagement. Therefore, accurate and reliable analytical models of architecture-property-relationships are needed for analysis and design. This thesis investigates the contact kinematics and mechanics of biomimetic scale-covered plates subjected to bi-directional bending. Both synclastic and anti-clastic deformations of the plate are considered. The mechanical moment-curvature relationships are derived using the work-energy balance principle. The results show that when a plate is bent to a certain curvature, a quasi-rigid locked emerges for both synclastic and anticlastic curvature. Interestingly, while for anticlastic bending, the curvature at locking is nearly the same curvature as a beam with equivalent geometry and configuration, for synclastic bending, locking occurs significantly earlier due to cross-curvature effects. The moment-curvature relationships indicate strongly anisotropic behavior of the plate. The anisotropy itself was not constant, being strongly influenced by the state of deformation. The effect of scale arrangement parameters (lattice geometry) directly influenced the nonlinear behavior including the locked state. The analytical models developed are compared with equivalent FE analysis for validation for select cases and excellent agreements have been found. The outcome of this work would enhance the understanding of the nonlinear and anisotropic behavior of scale-covered plate systems, paving the way for systematic design and integration tailored for specific applications.
|
Page generated in 0.4468 seconds