Browsing by Subject "plastic behavior"

Now showing 1 - 3 of 3

A Comparison of Modeling Methods for Predicting the Elastic-Plastic Response of Additively Manufactured Honeycomb Structures
(University of Texas at Austin, 2018) Sharma, Raghav; Le, Thao; Song, Jiaxu; Harms, Ethaniel; Sowa, Daniel; Grishin, Alex; Bhate, Dhruv
Valid and accurate models describing the mechanical behavior of additively manufactured cellular materials are crucial to enabling their implementation in critical-to-function parts. Broadly speaking, the modeling approaches commonly used in the literature fall into three categories. Each of these differs in the level of discretization at which the cellular behavior is modeled: at the level of each material point, at the level of the unit cell or at the level of a connecting member that constitutes a unit cell. Each of these three approaches relies on different characterization techniques and the way in which the resulting data is leveraged in the development of the model. In this work, we critically examine all three modeling approaches using FEA and compare their accuracy in the prediction of the elastic and plastic behavior of experimentally characterized hexagonal honeycomb structures made with Fused Deposition Modeling, and discuss the pros and cons of each method.
Experimental Analysis on an Additively Manufactured ABS Living Hinge
(University of Texas at Austin, 2014) Gribbins, Cassandra; Steinhauer, Heidi M.
A study on the plastic behavior of an additively manufactured acrylonitrile butadiene styrene (ABS) living hinge was conducted using a MakerBot 2X. Initial research included numerical and analytical linear analyses on a typical living hinge design. This paper introduces the portion of the research that explores the application of traditional design practices to entry-level additive manufacturing machines. Tensile testing for material properties was conducted to refine the numerical model. Experimental rotational testing was conducted for data on the non-linear, plastic behavior experienced during application. Verification of the numerical model with experimental results will be used to guide future work on exploring alternate design geometries that leverage the advantages of additive manufacturing’s design freedom for smoother stress distribution on the hinge.
Incorporation of Automated Ball Indentation Methodology for Studying Powder Bed Fabricated 304L Stainless Steel
(University of Texas at Austin, 2018) Karnati, Sreekar; Hoerchler, Jack; Flood, Aaron; Liou, Frank
Automated Ball Indentation (ABI) is a viable method for estimating the ductility, yield stress, and ultimate stress, among other metrics, in different metallic materials. Currently, ABI data analysis utilizes Holloman’s Power Law to model the plastic region of the true stress-true strain curve. While this formulation is accurate for some materials, its relevance for additively manufactured austenitic stainless steels, such as 304L, needed investigation. The deviation of the material’s plastic behavior from the Power Law was investigated. In order to better model this behavior, both the Voce and Ludwigson formulation were investigated. These formulations were tested for both wrought and additively manufactured 304L stainless steel. Regression analysis was used to choose the appropriate fit. The chosen formulation was then used to generate a material model to simulate the ABI process. These simulations were validated through experimental analysis.