Monday  |  Salon 10  |  05:10 PM–05:30 PM

#15770, Strain-rate Dependent Mechanical Response of Reinforced Ordered Elastomeric Cellular Structures

The advances in additive manufacturing are axiomatic, nonetheless, 3D printing of reinforced polymer matrix composites remain challenging due to the drastic differences between the attributes of the constituents. Such a dichotomy is exaggerated when the polymer matrix is an elastomer, and the reinforcing phase is a ceramic. This research aims to demonstrate the feasibility of additively manufacturing glass micro-balloon reinforced rubber-like resin using a stereolithography-variant 3D printing of ordered structures with hexagonal and cylindrical cell geometries. In addition to printing with neat rubber-like resin, the ultraviolet curable resin was reinforced with glass micro-balloons with a nominal diameter of ca. 10µm at weight ratios of 5%, 10%, and 20%. After optimization of the printing process, six samples of each unit cell geometry and reinforcement ratio were fabricated on a liquid-crystal display (LCD). All samples were conditioned in ambient conditions for two weeks before being submitted to quasi-static and impact mechanical tests. In the former, the samples were compressively loaded up to densification while collecting digital images for full-field strain analysis using digital image correlation (DIC). In impact tests, the samples were loaded by dropping a 850g mass from a height of 1m while recording the force-time history and deformation response using high-speed photography at a rate of 54000fps. Analysis of quasi-static and dynamic stress-strain curves and the local strain contour maps from the DIC analyses revealed the interrelationship between the local deformation mechanism and the global mechanical behavior of these 3D printed composite materials.

Anil Singh   San Diego State University
Vincent Ngo   San Diego State University
Nha Huynh   San Diego State University
Behrad Koohbor   Rowan University
George Youssef   San Diego State University