During installation of a High Density Polyethylene (HDPE) pipe by horizontal directional drilling, the polymer pipe is subjected to cyclic axial stress and strain, as each drilling rod is removed from the drill string. It then experiences periods where the ends are free, then has total length that is constant over its service life (after it is fixed to appurtenances).
Abdul developed a new viscoelasticviscoplastic constitutive model for HDPE, and developed new computational procedures to calculate axial forces during and after installation. The model accounts for the time dependent response of the HDPE, and provides the distribution of axial force along the pipe during construction and over its entire service life. The analysis provides peak axial force in-service (near the centre of the pipe), and decreases in magnitude over time. Soil stiffness is incorporated based on stiffness calculated using three dimensional finite element analysis.
Abdul’s outstanding graduate course grades and his publication record earned him an NSERC PGSD doctoral student scholarship. Abdul was also funded to attend the 8th International Trenchless Technology Colloquium in Sydney, Australia (2006), a meeting of trenchless researchers held every year or two preceding the international No- Dig Conference.
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