Student Chapter
Student Chapter
This chapter is a nationwide chapter to help promote computational mechanics to young researchers and improve student engagement and professional development within our community.
USACM Student Chapter Seminar Series
May 20, 2025: 11AM EDT
Join via Zoom: https://us06web.zoom.us/j/83451935254?pwd=SUh2eHlzTlRqVHJVb0pDbE1YWS95Zz09
Speaker: Dr. Xiaoheng Zhu, University of Pennsylvania
Title: Design of Non-deterministic Architected Structures via Bio-inspired Distributed Agents
Abstract:
Materials in nature often exhibit a significant degree of spatial variation and/or stochasticity in structuralhierarchy across different length scales. These qualitative differences result from the different manufacturing processes used in the two cases: Precision manufacturing (including 3D printing) follows the deterministic workflow of traditional manufacturing: all structural and compositional features must be determined in advance; an ordered list of precise steps must be followed; and, often, the material feedstock must be pure and homogeneous. While these techniques can enable extreme precision, the processes are brittle: material defects, interfacial incompatibilities, and process deviations may cause immediate failure, or unexpected premature failure when the structure is mechanically loaded. In contrast, natural materials are generated by decentralized, distributed processes involving many simple agents. For example, honeycombs are generated via the collective action of many bees, each of which performs actions based on its local environment rather than on a high-level, deterministic plan. Termite nests are also constructed via distributed action, with spontaneous organization via stigmergic communication. Here, we generate non-deterministic architected materials via simulations of swarms of simple, distributed bio-inspired agents just like bees and ants. We start by considering simple rules that agents might obey (n-Furcation rule), and the structures that would result from these distributed rules (analogous to process-structure relationships in materials science). Then we quantify the mechanical properties (e.g., strength and energy dissipation) of the structures generated by these rules (analogous to structure-property relationships in materials science). To accomplish an integrated analysis that covers rules, structures, and properties, we built a simulation platform that can realize: 1) intensive virtual design, 2) high fidelity finite element modeling (e.g., predicting materials damage evolution), 3) rapid prototyping and testing. Through this rule-structure-property platform, we investigated the failure characteristics of agent-generated lattice structures, and compared maximum tensile reaction load, total energy dissipation, percentage of energy dissipation post yield, and displacement of ultimate failure. We then consider how different assumptions about the capabilities of the agents (e.g., additional sensing modalities) would enable additional behaviors (and, hence, different structures and properties). Most of the design spaces in nature are not perfect and may include obstructions in the environment. We implement simple distributed agents with local interaction functions into a complex discontinuous construction area. We found that the level of average energy dissipation of lattices generated by agents with local interaction capability in the discontinuous design space is 19.6% higher than that of the regular lattices with the same relative density. Our approach is conceptually different from existing approaches, with the non-deterministic structural features intrinsically generated via the collective action of a large number of simple, decentralized agents (which are only aware of their immediate environment), rather than using algorithms to perturb or introduce disorder/randomness in topology.
Bio:
Dr. Xiaoheng Zhu is the research assistant in the Department of Mechanical Engineering and Applied Mechanics at University of Pennsylvania. His research interest majorly focuses on designing architected materials/structures with enhanced failure characteristics including fracture toughness, buckling resistance and impact resistance. His past research projects include bamboo inspired architected structures with enhanced damage tolerance, a bees/ants inspired distributed non-deterministic lattice design algorithm and pneumatic controlled architected materials with tunable buckling resistance.
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FAQ
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Additionally, USACM student members who have graduated within 2 years are also eligible to participate in student events.
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Organization
2023-2025
Mentors
Jessica Zhang, Carnegie Mellon University
John Evans, University of Colorado Boulder
David Littlewood, Sandia National Laboratories
Patrick Diehl, Los Alamos National Laboratory
Osama Raisuddin, Rensselaer Polytechnic Institute
Student Leadership
Chair: Yanrong Xiao, Yale University
Vice-Chair: Joan Ejeta, North Carolina A&T State University
Member-at-Large: Joseph Amponsah, Iowa State University
Elaheh Mehdizadeh, University of Pittsburgh
Dila Kandel, University of Utah
Executive Members
Xuan Hu, University of California, Berkeley
Ozge Ozbayram, Johns Hopkins University