Development of Control Setup for a Material Testing Machine and Experimental Analysis of the Effect of Void Volume Fraction on the Strength of Recycled High-Density Polyethylene Material
Abstract
This study is part of a larger research effort to investigate the mechanical response of
composite beams to cyclic loading caused by waves striking beams imbedded in a low-cost sea
wall. In the course of the research, it has been determined that material characterization of the
beams is needed, and toward this end an MTS (Materials Test Systems) testing machine has been
purchased by the TAMU Ocean Engineering Department. The testing machine was used for the
purpose of testing recycled high-density polyethylene glass fiber composite specimens in order to
characterize the stress-strain response and to measure the effect of void volume fraction (VVF)
within the high-density polyethylene beams. Samples taken from different areas of the beams with
varying VVF were tested and the effect of these voids was investigated for the purpose of
determining the efficacy of deploying these structural components within low-cost sea walls. The
study includes developing testing protocols, calibrating, and proof testing the machine in order to
perform the experiments. Since the lab’s testing machine does not have a controller, a control setup
is developed herein to control the MTS Testing Machine with signal processing via a National
Instrument USB-6346 Data Acquisition Device and LabVIEW software.
Results display the decrease in the stiffness as the VVF increases as well as decreases in the
ultimate stress and ultimate strain. Increasing strain rates displayed higher stiffness, ultimate stress, and ultimate strain values. The results are discussed and invalid tests are described
in detail wherein large voids locally misrepresent the general behavior and are incongruent with
the valid tests.
Subject
HDPEhigh-density polyethylene
strain rate
material properties
stress-strain curve
void volume fraction
Citation
Erener, Osman (2021). Development of Control Setup for a Material Testing Machine and Experimental Analysis of the Effect of Void Volume Fraction on the Strength of Recycled High-Density Polyethylene Material. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /196102.