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Full-Text Articles in Engineering
Methodologies For The Integrity Assessment Of Pipelines Containing Cracks, Haotian Sun
Methodologies For The Integrity Assessment Of Pipelines Containing Cracks, Haotian Sun
Electronic Thesis and Dissertation Repository
Cracking is a well-known failure mechanism that threatens the structural integrity of energy pipelines. As a special type of cracking, stress corrosion cracking (SCC) occurs if suitable tensile stress and corrosive environment are present simultaneously. When the basicity of the local electrolyte is close to 7, the failure mechanism is termed as near-neutral pH stress corrosion cracking (NNpHSCC). Cracks, including NNpHSCC, markedly diminish the burst capacity of pipelines through reducing their local wall thickness. Although commonly observed on in-service pipelines and being one of the leading causes of pipeline failures, the studies on cracks, especially NNpHSCC, have not yet received …
Assessment Of Tropical Cyclone Wind And Wave Hazards And Their Effect On The Reliability Of Wind Turbines, Chao Sheng
Assessment Of Tropical Cyclone Wind And Wave Hazards And Their Effect On The Reliability Of Wind Turbines, Chao Sheng
Electronic Thesis and Dissertation Repository
Tropical cyclone (TC) induces strong winds, heavy rainfalls, and storm surge. They cause fatalities and property damages, especially in the coastal regions that are prone to TC hazards. The TC wind or wave assessments were reported in the literature. The assessment provides the required hazard characterizations for assessing the reliability and risk of structures such as onshore and offshore wind turbines (WTs). The present study considered sites near the coastline of mainland China. It is focused on 1) the assessment of using different historical best-track datasets on the development of stochastic TC track models and on the estimated TC wind …
Uncertainties In Internal Pressure Of Oil Pipelines And Implications For The Reliability Analysis, Yue Liu
Uncertainties In Internal Pressure Of Oil Pipelines And Implications For The Reliability Analysis, Yue Liu
Electronic Thesis and Dissertation Repository
The internal pressure is the most important operational load for oil and gas pipelines. The maximum operating pressure (MOP) is the maximum pressure the pipeline is qualified to be operated according to a given standard. In deterministic fitness-for-service (FFS) assessment of in-service pipelines containing flaws such as corrosion defects and cracks, the remaining pressure containment capacity of the pipeline is evaluated and compared with MOP multiplied by a factor of safety to determine if immediate rehabilitation actions for the pipeline are necessary. However, the actual internal pressure of an in-service pipeline is however uncertain and fluctuates with time. Due to …
Aversion And Warning Factors For Assessing Existing Reinforced Concrete Structures, Marcie Van Weerdhuizen
Aversion And Warning Factors For Assessing Existing Reinforced Concrete Structures, Marcie Van Weerdhuizen
Electronic Thesis and Dissertation Repository
In a world of aging infrastructure, sustainability initiatives require additional investment in the assessment of existing reinforced concrete structures. Reliability-based assessment should minimize costs by reducing conservatism, while ensuring levels of safety equivalent to those for new designs. Current Canadian and US provisions assign target reliability levels for structural assessment based on criteria including occupancy type, expected failure behaviour, and the effect of element failure on the overall structural integrity. These criteria are defined using discrete and qualitative parameter values. It is shown that the true structural conditions can be better represented by verifying the applicability and completeness of these …
Partial Material Strength Reduction Factors For Aci 318, Tong Zhang
Partial Material Strength Reduction Factors For Aci 318, Tong Zhang
Electronic Thesis and Dissertation Repository
The strength reduction factors, phi, defined in ACI 318-14 for different structural actions and elements lead to inconsistent results. This study proposes partial material strength reduction factors for concrete, phic, and reinforcing steel, phis, that yield similar design strengths and more consistent reliability indices. Three structural actions are investigated: moment; shear; and, combined moment and axial force. The first-order, second-moment method is used to compute reliability indices for moment and shear, and Monte Carlo simulation is used for combined moment and axial force. The statistical parameters assumed for the professional factor for shear strength significantly impact …
Bayesian Analyses Of Metal-Loss Corrosion On Energy Pipeline Based On Inspection Data, Mohammad Al-Amin
Bayesian Analyses Of Metal-Loss Corrosion On Energy Pipeline Based On Inspection Data, Mohammad Al-Amin
Electronic Thesis and Dissertation Repository
Bayesian models are developed to calibrate the accuracies of high-resolution in-line inspection (ILI) tools for sizing metal-loss corrosion defects and to characterize the growth of individual defects on energy pipelines. Moreover, a methodology is proposed to evaluate the time-dependent system reliability of a segment of a pressurized pipeline containing multiple active corrosion defects. The calibration of ILI tools is carried out by comparing the field-measured depths and ILI-reported depths for a set of static defects. The proposed methodology is able to quantify the measurement errors of multiple ILI tools simultaneously and evaluate the correlation between random errors associated with different …