Akhavan Alavi S M, Ghajar R. Determination of Mechanical Properties of a Micro-Cellular Auxetic Structure Using Modified Strain Gradient Theory. Modares Mechanical Engineering 2023; 24 (1) :11-20
URL:
http://mme.modares.ac.ir/article-15-72124-en.html
1- Department of Mechanical Engineering, K. N. Toosi University of Technology
2- Department of Mechanical Engineering, K. N. Toosi University of Technology , ghajar@kntu.ac.ir
Abstract: (704 Views)
In this article, the determination of the mechanical properties of a micro-cellular auxetic structure is investigated. This lattice structure consists of hexagonal cells, whose cell-wall dimensions are on a micro-scale. First, using modified strain gradient theory (MSGT) and energy method, the mechanical properties of the micro-cellular auxetic structure are analytically obtained. Then for validation, Young's modulus of a micro-cellular auxetic structure is derived by tensile test and compared with theoretical results. The comparison of analytical and experimental results shows good agreement. A nanosecond laser cutting machine is used to fabricate the microcellular auxetic structure, and the ISO 6892-1 standard is used to perform tensile tests. The results show that the modified strain gradient theory plays an important role in determining the mechanical properties of micro-cellular auxetic structures. In some cases, the results of this theory are more than 100% different from the classical theory. In addition, it can be seen that by changing the dimensional parameters of the micro-cells, the mechanical properties of the auxetic structure can be tunable. For example, by reducing the magnitude of the angle of the cell wall, Young's modulus in the X 1 direction increases, and Young's modulus in the X 2 direction and the shear modulus of the structure decrease
Article Type:
Original Research |
Subject:
Micro & Nano Systems Received: 2023/10/25 | Accepted: 2024/03/2 | Published: 2023/12/31