Session: 13-03-01: General: Mechanics of Solids, Structures and Fluids I

Paper Number: 166449

The Mechanical Responses of Pre-Stressed Meta-Cells 

Pre-stressed materials are ubiquitous in engineering, nature, and biomedical applications, playing a critical role in enhancing structural performance, durability, and functionality. From tendon mechanics and plant cell walls to pre-stressed concrete, tensegrity structures, and high-performance composites, the ability to manipulate internal stress states enables the development of materials with superior mechanical properties. These materials often demonstrate inherent resilience, impressive strength-to-volume ratios, and effective energy absorption. Pre-stress serves as a proactive mechanism, inherently conditioning the material beforehand to enhance its ability to withstand and adapt to future loads efficiently. By intentionally adjusting internal stress and strain, pre-stress becomes a powerful design tool, enabling precise control over material behavior, particularly in applications requiring superior energy dissipation and structural resilience.

In this investigation, we are particularly interested in pre-stressed meta-cells with circular-ring geometry and reinforcement core structures. We present a computational framework for simulating the response of the stress-free and pre-stressed unit meta-cells under external loading, focusing on both symmetric and chiral designs subjected to compressive forces. An initial comparative analysis explored a broad range of pre-stress conditions to identify optimal settings. The objective was to interpret the often-complex relationship between pre-stress and the mechanical response of the pre-stressed unit cells, aiming to find the most effective combinations for various applications. Our goal was to observe how each design responded and, more importantly, understand the underlying reasons behind those reactions.

Results clearly demonstrated the superior performance of pre-stressed meta-cell designs when subjected to vertical compression. The enhanced performance of pre-stressed meta-cells can be attributed to the synergistic effect of geometry and pre-stress distribution. The interaction between these two factors modulates the deformation mechanisms, leading to more efficient stress redistribution and improved mechanical resilience. Essentially, the pre-stress acts as a key enabler, unlocking the full potential of the meta-cell design and allowing for a more efficient load transfer throughout the meta-cell structure.

This research highlights the profound impact of pre-stress on the mechanical behavior of metamaterials, demonstrating that pre-stress is not merely a passive feature but an active design parameter that can be leveraged to achieve exceptional material performance. By carefully tuning pre-stress states and optimizing meta-cell geometries, we can design materials with tailored mechanical responses, unlocking new possibilities for high-performance applications. The insights gained from this study could pave the way for advancements in diverse fields such as impact protection, vibration damping, and structural engineering. Furthermore, the deeper understanding of the interplay between geometry and pre-stress provides a foundation for future innovations in adaptive and multifunctional materials.

Presenting Author: Harisheswara Reddy Eargamreddy Northeastern University

Presenting Author Biography: I am a dedicated graduate student in the Department of Mechanical Engineering at Northeastern University, specializing in applied mechanics. My research focuses on studying solids, structures, and fluids through innovative experimental, computational, and analytical approaches. As an active member of the academic community, I have collaborated with leading researchers and contributed to organizing the Mechanics of Solids, Structures, and Fluids. My research interests include material behavior, structural dynamics, and fluid-structure interactions under extreme conditions.

Authors:

Harisheswara Reddy Eargamreddy Northeastern University
Yunzheng Yang Northeastern University
Siyao Liu Northeastern University
Sinan Muftu Northeastern University
Kai-Tak Wan Northeastern University
Yaning Li Northeastern University