Research

Dr. Zhou's research is focused on probabilistic degradation modeling for metal-loss corrosion and stress corrosion cracking on pipelines based on inspection data, optimal repair and maintenance strategies for degrading pipelines, deterministic and probabilistic assessments of buried pipelines subjected to ground movement, and fracture mechanics-based design and assessment of pipelines with respect to planar defects. His research is closely related to and supported by the Canadian pipeline industry.

Current Research

Probabilistic Modeling of Degradations of Energy Pipelines Based on Inspection Data

This research is focused on developing probabilistic models to characterize time-dependent degradation of energy pipelines due to metal-loss corrosion and stress corrosion cracking based on periodic inspection data. The goal is to develop models that are accurate and practical, and will facilitate the reliability- and risk-based pipeline integrity management with respect to corrosion and stress corrosion cracking. The key challenge is to take into account the spatio-temporal uncertainties inherent to the degradation processes as well as the sizing and detecting uncertainties associated with the inspection data.

Reliability Evaluation of Pipelines Subjected to Ground Movement

This research is focused on applying the strain-based, as opposed to the stress-based, methodologies to evaluate the probability of failure of steel oil and gas pipelines subjected to ground movements due to unstable slopes, frost heave, thaw settlement and earthquake-induced permanent ground deformation. The key challenges in the research are to evaluate the strain demand due to the ground movement by properly modeling the pipe-soil interaction and corresponding strain capacities of the pipeline. The stochastic finite element method is employed to deal with the spatial variability of the pipe and soil properties. Efficient reliability methodologies such as the FORM and SORM are employed to carry out the reliability analysis.

Fracture Toughness Transferability of Pipeline Steels

This research involves experimental and numerical studies to address the application of the fracture toughness (such as JIc, J-R and CTOD-R) determined from the small-scale laboratory specimens to the design and integrity assessment full-scale pipelines in practice. The focus of the research is to develop crack tip constraint-corrected fracture toughness representations as well as small-scale laboratory specimens that have similar crack tip stress and strain fields as the full-scale pipelines subjected to internal pressure and external loading. Both experimental studies utilizing a 500-kN MTS servo-hydraulic test frame and numerical studies based on three-dimensional finite element analyses are key components of the research.

Optimal Maintenance and Repair Strategies for Pipelines

This research is aimed at developing optimal maintenance and repair strategies for pipeline with respect to multiple integrity threats such as the third-party interference, metal-loss corrosion and stress corrosion cracking. The objective functions considered include the risk, reliability and maintenance costs. The maintenance and repair actions considered include patrol frequency and method, inline inspection interval, criteria for excavating and repairing corrosion defects, and intensity and frequency of the hydrostatic tests.

My Research Group

Name	Thesis Title	Degree	Status	Current Position
N. Zhang	Reliability and Statistical Analysis of RC Beams Considering Moment-Shear Interaction	MESc	Completed	EIT – TransCanada Pipelines, Calgary, AB
G. X. Huang	Model Error Assessment of Burst Capacity Models for Energy Pipelines	MESc	Completed	EIT – TransCanada Pipelines
S. Liu (co-supervised with Prof. Bartlett)	Alternative Load Paths in Steel Through-truss Bridges	MESc	Completed	EIT – AECOM, Markham, ON
M. Al-Amin	Bayesian Analysis of Metal-loss Corrosion on Energy Pipelines Based on Inspection Data	MESc	Completed	EIT – TransCanada Pipelines
B. Kim (co-supervised with Dr. Eric Ho)	Predictions of Wind Loads on Tall Buildings: Development and Applications of An Aerodynamic Database	MESc	Completed	EIT - Stephenson Engineering Ltd., Toronto
Y. F. Huang	Finite Element Analyses of Single-edge Bend Specimens for J-R Curve Development	MESc	Completed	PhD student supervised by W. Zhou
S. Zhang	Development of Probabilistic Corrosion Growth Models with Applications in Integrity Management of Pipelines	PhD	Completed	Risk Engineer - TransCanada Pipelines
H. Qin	Bayesian Analyses of Generation and Growth of Corrosion Defects on Energy Pipelines	MESc	Completed	EIT - Gradient Wind Engineering Inc., Ottawa
Z. Yan	Impact of Curved Crack Front on the J-integral and Compliance Evaluation of Single-edge Bend Specimens	MESc	Completed
E. Wang	Experimental and Numerical Studies of Fracture Toughness Determination for Pipeline Steels	PDF	Completed
C. Lam	Burst Capacity of Pipelines with Anisotropic Material Properties	MESc	In progress
C. Gong	Multi-objective Optimization of Maintenance Plans for Energy Pipelines	PhD	In progress
J. L. Mendez	Reliability Evaluation of Pipelines Buried in Unstable Slopes	PhD	In progress
T. Siraj	Spatial Correlation of Corrosion Defects and Its impact on Growth Modeling for Energy Pipelines	PhD	In progress
Y. F. Huang	Impact of Residual Stresses on the J-R curve Evaluation Based on SE(T) Specimens	PhD	In progress

Opportunities In My Group

MESc and PhD positions may be available for candidates with strong academic background and/or research records as well as keen interests in integrity management of oil and gas pipelines. Please contact Prof. Zhou for details.