Session: 12-18-01: Functional Origami and Kirigami-inspired Structures and Metamaterials

Paper Number: 95190

95190 - Nonlinear Stability Analysis of a Reconfigurable Origami-Inspired Structure 

This study aims to investigate the nonlinear stability of a reconfigurable origami-inspired structure. Origami techniques provide practical approaches to construct a three-dimensional (3D) structure from a two-dimensional (2D) model. They have been utilized extensively in the design of various mechanisms including robotic, antennas, aerospace mechanism, architecture, acoustic structure, frequency selective surfaces, military, etc. We use the Kresling origami pattern to design a reconfigurable structure. The Kresling pattern is one of the most efficient and extensively used origami structures. This pattern rotates in the axial direction and is commonly used in the construction of foldable cylindrical structures subjected to axial load.

The increasing variety of origami applications has attracted attention to this topic in recent years. Due to considerable strain changes, particularly in creases, several difficulties arise during the design process of an origami structure. Furthermore, in the mechanical analysis, the symmetry-breaking and rotation of valley and mountain sections should be detected while buckling happens. As a result, it is necessary to rigorously study the folding process of origami structures to examine mechanical responses. In addition, it could be used for evaluating the performance of the design. Experimental can be used to analyze the stability; however, this approach is expensive computationally. We use the finite element method (FEM) to explore the effect of design parameters on the stability of the proposed origami structure.

In this study, we use available FEM in ANSYS software package to carry out the nonlinear stability of the structure and predict the folding process of the Kresling origami structure. This study is carried out for different geometric parameters: length ratio (b/a) and radius of the base. We discretize the model into smaller elements using the ANSYS shell element methodology. This assumption is reasonable since the wall thickness is much smaller than the height and width of the structure. The structure is meshed using four nodes structural shell elements; SHELL181. This element type is defined by four nodes which each node has six degrees of freedom: x, y, and z translations, as well as rotations about the x, y, and z-axes. It is appropriate for moderately-thick shell structures, linear, large rotation, and/or large strain nonlinear, and layered applications.

We employ CONTA174 and TARGE170 elements to model the contact and sliding between two interfaces during the folding process. The contact and target surfaces are defined using CONTA174 element for the upper triangle surfaces and TARGE170 element for the lower triangle surfaces, respectively. CONTA174 is a surface-to-surface contact element and uses Gauss integration points method to detect the contact. The contact is assumed to be friction-less between two interfaces.

We fix the bottom surface in all directions. To capture the folding behavior of the structure, a uniform linear displacement is applied at the top plate along the axial direction. All degrees of freedom of the top plain are restrained except the translation degree of freedom in the axial direction. In order to have a quasi-static compression, we apply the displacement loading gradually. The displacement loading step size depends on the height of the structure. The number of step size varies between 50 to 1000, which the software increases when the solution counters divergence. Newton-Raphson method is used as a solver with the nonlinear control tolerance (force convergence) of 0.5\% in this study.

A hexagonal origami structure with three stories is used to investigate the effect of the length ratio (b/a) on the life cycle. The length ratio (b/a) is assumed to be 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, and 2.2 in this section. Other geometric parameters are H = 150 mm, R = 60 mm, and thickness = 2 mm. It is found that increasing b/a from 1.5 to 2.0 decreases the structure's stability.

 

Reference:

Moshtaghzadeh, M., Izadpanahi, E. and Mardanpour, P., 2022. Prediction of fatigue life of a flexible foldable origami antenna with Kresling pattern. Engineering Structures, 251, p.113399.

Presenting Author: Mojtaba Moshtaghzadeh Florida International University

Presenting Author Biography: Mojtaba Moshtaghzadeh joined the FSI lab at the Florida International University as a Ph.D. student in Jan. 2019. He received his Master and bachelor’s degrees in mechanical engineering from Iran. He has experience working in industrial projects such as design of pressure vessels, heat exchangers, and steam boilers for more than seven years. In addition, he has conducted research in several engineering fields: Aeroelasticity, Structural Dynamic, FEA, and Applied Numerical Methods. His Ph.D. research is focused on the design and analysis of reconfigurable structure-inspired origami patterns.

Authors:

Mojtaba Moshtaghzadeh Florida International University
Ali Bakhtiari Florida International University
Pezhman Mardanpour Florida International Univeristy