Crack Propagation in 3-D Printed PLA: Finite Element Modeling, Test Bed Design, and Preliminary Experimental Results

Patterson, Albert E.

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https://hdl.handle.net/2142/100334 Copy

Description

Title

Crack Propagation in 3-D Printed PLA: Finite Element Modeling, Test Bed Design, and Preliminary Experimental Results

Author(s)

Patterson, Albert E.

Issue Date

2018

Keyword(s)

• Fracture mechanics
• 3-d printing
• anisotropic materials
• PLA
• polymer testing

Abstract

The present study was a preliminary exploration of crack propagation in 3-D printed polylactic acid (PLA), a bio-mass generated recyclable polymer with excellent mechanical properties and many consumer and industrial applications. This material has not been explored in great depth in the literature, so little is known about its crack propagation behavior; the 3-D printed mesostructure of the material adds additional complexity to the problem. Simple finite element models of this mesostructure were created to demonstrate this and place the rest of the study in context. Three test articles were designed for 3-point-bend testing, each meant to test a different aspect of the crack development and growth. A desktop-sized testbed was designed and developed to test these articles. A series of six experiments were run, each of the test article designs in each of two print orientations. The six experiments were each replicated twice, for a total of 18 tests, to ensure repeatability and reliability of the collected data. The crack behavior overall seemed well captured using the developed experiment. Several potential improvements were identified and described. The validity of a linear-elastic, small-scale yielding assumption in the growth of cracks in PLA was also examined, as well as the crack velocity, crack stability, and fracture mode.

Type of Resource

other

Language

en

Permalink

http://hdl.handle.net/2142/100334

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