UPSCALE - Uniform Polyhedra Structures as Cosserat-type Architected Lattice matErials: Theoretical Groundwork, Additive Manufacturing and Validation

• Applicant: Professorin Dr. Christina Völlmecke
• Subject Area: Mechanics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 543895078

In this project, we introduce a novel subclass of architected materials, specifically lattice structures based on rigid uniform polyhedra. The rigid elements within these structures are interconnected by elastic struts, offering a chiral and antichiral mechanical response. By strategically combining elastic links of varying shapes, such as cylindrical and hyperboloid forms, we aim to fabricate mechanical metamaterials with unconventional properties, including auxetic behavior, twist-compression/extension coupling, acoustic wave localization, and the creation of topological band gaps. The principal aim of this proposal is to develop a micropolar (Cosserat-type) theory for mechanical metamaterials based on uniform polyhedra interconnected by chiral and antichiral links. Two distinct modeling approaches will be employed. The discrete model will assist in predicting the mechanical response of individual links. Subsequently, these discrete model results will inform the development of the continuum micropolar model, enabling the description of material behavior at the macroscale. Theoretical models will be compared against finite element simulations conducted using both commercial software and in-house developed codes. Computational analysis will additionally contribute to the design of topologies for various polyhedral metamaterials characterized by prominent auxetic and chiral mechanical responses. In subsequent stages, these optimized topologies will be employed to create specimens through various 3D printing technologies. The most suitable technology will be selected to fabricate specimens for experimental compression tests, complemented by deformation analysis utilizing digital image correlation. Ultimately, the results of laboratory tests will be juxtaposed with those obtained from analytical modeling and computational simulations. The proposed timeline for this endeavor spans 36 months, necessitating sustained collaboration between German and Israeli researchers in the domains of theoretical, computational, and experimental work. To execute this multifaceted project, a total of three doctoral candidates and two student assistants are sought from the collaborating institution.

• DFG Programme: Research Grants
• International Connection: Israel
• Co-Investigator: Professor Dr. Wolfgang H. Müller
• International Co-Applicant: Dr. Igor Berinskii