Characterizing tensile loading responses of 3D printed samples

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (page 38).An experimental study was performed to characterize the loading response of samples manufactured through 3D printing. Tensile testing was performed on a number of 3D printed samples created through Fused Filament Fabrication (FFF). Printed samples were made from ABS or PLA plastic. A range of infill densities from 25% to 100% were tested for each material. Additionally, samples were printed with layers at several angles relative to the tensile loading of the sample. Failure modes were characterized as either delamination in the elastic region, delamination in the plastic region, brittle fracture, or ductile fracture. Loading response curves were analyzed to find the peak load, structural stiffness, load at plastic yield, and effective strain at failure. Samples loaded along the printed layers with 100% infill density displayed the most favorable mechanical properties. Samples loaded perpendicular or at an angle to the printed layers failed at smaller loads and displacements. Additionally, samples printed at less than 100% infill also tended to fail sooner.by Christopher M. Haid.S.B