Multilayered Randomized Architected Material under Tensile Loading for a Tensegrity Structure

Abstract

Architected materials are a new class of materials that interlink practices in architecture and structural engineering to produce materials by conjugation of several simple materials through the interplay between geometry and material properties. Tensegrity structures are composed of struts and cables held in a state of self-stress. With a high strength-to-weight ratio, they provide opportunities for deployable and transportable bridges. Although tensegrity structures are indeterminate, cable damage is challenging to predict and detect a priori, which is aided by a resilient architected material segment as a structural health indicator. The technology of 3D printing complements the development of architected material. Computational studies have shown the effect of coordination number and cross-linking density on the stretch behavior of polymer networks for microscopic deformation scale. This paper presents the relationship between various parameters of multilayered randomized architected material (MLRAM) and its tensile behavior. The randomization of link orientation is to address the unknown direction of the critical force in the strut. A computational model calibrated through experimental testing was developed that mimics the tensile behavior of MLRAM. Using this model, the variation in the tensile behavior in terms of peak tensile capacity and postpeak behavior of MLRAM can be studied for various geometries with specific parameters. From the study, it is observed that the tensile capacity and stiffness of the MLRAM increase with a higher coordination number. The recent advancement of additive manufacturing and 3D printing have provided researchers with the scope to study the feasibility of many difficult geometries and its properties. This is one such study that develops and investigates the tensile properties of a newly developed multilayered randomized architected material (MLRAM). The tensile properties were determined experimentally for centimeter-scale 3D-printed models and a computational model was proposed to replicate the behavior in the linear static region. This novel study provides a preliminary idea of a new concept of architected material that can be extended to a three-dimensional concept in the future. First, the model helps researchers investigate various geometry and design materials with properties as required for specific applications. This proposed MLRAM extended into a three-dimensional material also has the potential to act as visual damage detection indicators that can be incorporated in highly redundant structural systems such as tensegrity structures.