J.J. Roger Cheng

University of Alberta | UAlberta · Department of Civil and Environmental Engineering and the School of Mining and Petroleum Engineering

The tensile strain capacity (TSC) of a welded pipeline under bending and/or axial loads is critical to pipeline integrity assessment, and the fracture toughness expressed as a J-R curve plays a key role in predicting the TSC. The single edge notched tension (SENT) tests have been recommended for fracture toughness measurement of pipelines due to th...

Onshore pipelines are generally required to transport various hydrocarbon fluids and other liquid consumables over considerably long distances. In many cases, pipe segments are unavoidably installed across geotechnically unstable environments, making them prone to significant ground deformation-induced stresses and strains which may lead to local b...

The integrity decisions for cracked pipelines can be made based on the conventional Finite Element Method (FEM). However, it is extremely time-consuming due to the requirement of remeshing to continuously conform to the geometric discontinuities as the crack propagates. The more recently developed Extended Finite Element Method (XFEM) provides a mo...

Pipelines can be exposed to a wide variety of loads, depending on the environment. These loads may impose large longitudinal plastic strain on pipelines, which could lead to the violation of the structural integrity of the pipeline. Reliable calibration of the strain capacity of pipelines plays an important role in the strain-based design method. I...

The cohesive zone model (CZM) is one of the most widely used damage models to describe the fracture processes of brittle and ductile materials, and has been usually combined with the conventional finite-element method (FEM). CZM in the context of the more effective extended finite-element method (XFEM) has recently been implemented in many applicat...

Gusset plates play a critical role in the behavior and stability of bracing systems and truss bridges. While the behavioral characteristics of gusset plates have been widely investigated and analysis procedures have been developed, considerable uncertainty exists in the design equations, due primarily to the complexity of stress distribution in the...

Rupture of steel pipelines due to combined loading conditions leads to the loss-of-containment that may be accompanied by property damage or fatal accidents. Therefore, the understanding of the fracture characteristics of steel grades used in the pipelines is essential for a safe and reliable design. In this study, a set of small-scale fracture tes...

Adoption of cylindrical shell structures for various load-resistance applications has enjoyed wide-spread acceptance in the field of civil, mechanical and aerospace engineering, mainly due to the exceptional structural efficiency of cylindrical shells to withstand significant longitudinal and circumferential in-plane loading without bending. Howeve...

Pipelines subjected to displacement-controlled loading such as ground movement may experience significant longitudinal strain. This can potentially impact pipeline structural capacity and their leak-tight integrity. Reliable calibration of the tensile strain capacity (TSC) of pipelines plays a critical role in strain-based design (SBD) methods. Rec...

The integrity assessment of dents in liquid pipelines, as regulated by codes and standards, is based mostly on depth and threat integration, with strain analysis incorporated as a nonmandatory recommendation for gas pipelines. There have been incidents in which the current regulatory criteria have not successfully predicted imminent failures of den...

This paper presents a technique that uses finite element method (FEM) to analyse energy release rate (G) for delamination growth in fibre-reinforced polymers (FRP). Using end-notched-flexure specimen as an example, G values obtained from the technique show excellent agreement with those from compliance derivative or virtual crack closure techniques...

Pipelines typically exhibit significant inelastic deformation under various loading conditions, making it imperative for limit state design to include considerations for the deformational capacity of pipelines. The methods employed to achieve higher strength of API X80 line pipe steels during the plate manufacturing process tend to increase the har...

The coupled steel plate shear wall (C‐SPSW) configuration has been investigated by researchers as a means of improving the overturning stiffness and architectural flexibility of SPSW structures. While C‐SPSWs have been shown to exhibit excellent seismic performance, the fabrication cost associated with the high number of moment‐resisting connection...

The single edge notched tension (SENT) test is commonly used to evaluate the less-conservative fracture toughness of pipeline steels. The R-curve (crack tip opening displacement (CTOD)-crack growth) behavior measured by SENT tests is similar to that measured during full-scale tests. This paper compares the ductile fracture mechanism of X42 grade st...

In service pipelines exhibit bending loads in a variety of in-field situation. These bending loads can induce large longitudinal strains, which may trigger local buckling on the pipe's compressive side and/or lead to rupture of the pipe's tensile side. In this article, the post-buckling failure modes of pressurized X65 steel pipelines under monoton...

The coupled steel plate shear wall (C-SPSW) configuration consisting of two SPSWs linked by coupling beams at the floor levels, in addition to providing architectural flexibility, has been shown to exhibit superior seismic performance. While the shear strength of the infill panels due to tension field action is the primary source of lateral load re...

The buckling capacity of uniformly compressed flat plates has been investigated in this study. Material properties were characterized based on parameterization of the stress-strain curves using a simple and novel mathematical expression. Idealized stress-strain relationships were developed using the proposed material model and extensive parametric...

Currently, there is a lack of direct design provisions in structural codes and literature that address design temperatures in tunnel structures and thus it is common practice for designers to resort to bridge codes. The main focus of this paper is the study of the temperature distribution in concrete road tunnels due to ambient temperature. In this...

Pipelines used to transport oil and gas products are often subjected to external forces during its construction or operation, which can result in the formation of dents in the pipe. Various pipeline codes have stipulations on how a dent's severity can be ascertained in order to prioritize repairs. The most prominent being the depth-based criterion,...

The structural integrity of underground pipelines are subject to a major threat from permanent ground displacements when they cross active tectonic (e.g., strike-slip) faults, because of large strains potentially induced in pipes, leading to pipe buckling and possible rupture. In this paper, the buckling behavior of X80 pipe is studied numerically...

Oil and gas pipelines traverse long distances and are often subjected to mechanical forces that result in permanent distortion of its geometric cross section in the form of dents. In order to prioritize the repair of dents in pipelines, dents need to be ranked in order of severity. Numerical modeling via finite element analysis (FEA) to rank the de...

Train-mounted vertical track deflection (VTD) measurements offer new opportunities for estimating rail bending stresses over long distances. The estimations are possible because of mathematical correlations among rail deflections, rail stresses, and the loads applied to the rail. Previous numerical studies conducted by the authors resulted in a met...

This paper presents a new methodology for the estimation of bending stresses over long sections of rails from the vertical track deflections measured using train-mounted instrumentation. The basis of this method is to apply mathematical correlations between the rail deflections and stresses to interpret the deflection measurements. A new finite ele...

This paper proposes a new method for hydrokinetic pressure and fluidic drag evaluation of non-Newtonian power-law slurries flowing within a borehole during horizontal directional drilling (HDD) pipe installation operations. The method divides the bore path into three segments, each associated with a different stage of slurry flow pattern. For each...

This paper presents a new methodology to quantify the vertical bending moments that generate in rail under the passage of train wheels. In this method, the rail-bending moments are quantified from track modulus estimated using train-mounted vertical track deflection (VTD) measurements. This provides a practical approach for quantifying the rail-ben...

Having investigated the plastic behavior and mechanisms of steel plate shear walls with outriggers (SPSW-O) introduced in Part I, it was shown that such systems are considerably effective in improving the flexural stiffness of conventional SPSWs. This paper describes procedures for the efficient design of SPSW-Os employing the principles of plastic...

The extended finite element method (XFEM) has recently become a very effective method to investigate the propagation of cracks in various structures under complex loading conditions. However, its use in the pipeline industry has been limited. This paper aims to apply XFEM to model our previous experimental results on NPS 12 grade of X52 steel pipes...

Pipe bends are frequently used to change the direction in pipeline systems and they are considered one of the critical components as well. Bending moments acting on the pipe bends result from the surrounding environment, such as thermal expansions, soil deformations, and external loads. As a result of these bending moments, the initially circular c...

The environmental contamination due to the leakage of energy pipelines is a serious hazard to the public property and safety. Hence, any premature rupture should be dealt with in the design and the operating mode of steel pipes. A large amount of complexity is involved in the soil-pipe interactions that makes it so challenging to discover the physi...

Steel pipelines are subjected to a variety of complex, and sometimes difficult to predict, loading schemes during the fabrication, installation and operation phases of their lifecycles. Consequently, the mechanical behavior of steel pipelines is not only influenced by the steel grade but also by the loading history of the pipe segments. Due to the...

Advances in the interpolation techniques of discrete data points and its application to monitoring the displacement of physical infrastructure has led to improved analytical strain evaluation procedures. In order to generate a detailed mathematical model of the strain state of a dented pipeline, it is necessary to decompose the deformation data obt...

Steel plate shear walls (SPSWs) are ductile and economical energy dissipating systems for buildings located in regions of high seismic risk. In spite of many advantages of SPSWs; however, their overturning stiffness is relatively low, especially when their width is narrow compared to the building height. Therefore, additional flexural stiffness mus...

The true stress-true strain characterization of a metallic material may be established using a constitutive mathematical expression such as the Ramberg-Osgood stress-strain equation, or any of the various alternative stress-strain curve models which have been developed for the characterization of metallic materials over the full-range of the stress...

A new computational methodology is presented for the dynamic analysis of multibody systems with multiple clearance joints by vector form intrinsic finite element method. A joint model is developed to simulate the motion of ideal and clearance joints for multibody systems. The dynamic behaviour of a four-bar mechanism with three clearance joints in...

This paper proposes a new method for evaluating hydrokinetic pressure and fluidic drag changes during pipe installation operations using Horizontal Directional Drilling (HDD). The method is based on applying the solution of eccentric annular flow problem using Finite Volume Method (FVM) to the HDD case. Using MATLAB programming language, a computer...

Pipe elbows are frequently used in a pipeline system to change the directions. Thermal expansion and internal pressure results in bending moments on the bends causing ovalization of the initial circular cross-section. The ability of the bend to ovalize will result in an increase in the bend flexibility when compared to straight pipes [1]. In case o...

Pipelines can be subjected to bending loads due to a variety of factors such as seismic activity, slope instability or discontinuous permafrost. Experimental studies of Sen [1], [2], [3] showed that pipelines can fail under bending loads due to pipe body tension side fracture which is a mostly overlooked failure mode in pipelines. Recent numerical...

Over the past two decades, a rolling deflection measurement system aiming to continuously measure the track modulus has been under development at the University of Nebraska – Lincoln under the sponsorship of the Federal Railroad Administration. This system measures the relative vertical distance (referred to as Yrel) between the rail surface and th...

Wide plate testing has been traditionally applied to evaluate the tensile strain capacity (TSC) of pipelines with girth weld flaws. These wide plate tests cannot incorporate the effect of internal pressure, however, numerical analysis in recent studies showed that the TSC is affected by the level of internal pressure inside the pipeline, Y.Wang (20...

The effects of the initial geometric imperfections on the buckling response of grade X-100 UOE manufactured pipes are studied through finite element analysis (FEA). The initial geometric imperfections had been previously measured and quantified in terms of deviations in outside radius (OR) and wall thickness. The measurement results are used to dev...

1. ABSTRACT Horizontal Directional Drilling (HDD) is a technology for pipe installation under obstacles. To have a successful installation, an appropriate estimation of the expected forces experienced by the pipe during installation phase is essential, so the pipe can be sized accordingly. A component of the pullback force is fluidic drag that resu...

Horizontal Directional Drilling (HDD) is a technology for pipe installation under obstacles. To have a successful installation, an appropriate estimation of the expected forces experienced by the pipe during installation phase is essential, so the pipe can be sized accordingly. A component of the pullback force is fluidic drag that results from the...

This paper proposes a general method for estimating pullback force applied on polyethylene (PE) pipes during horizontal directional drilling (HDD) installations based on adapting the Capstan equation to a PE pipe negotiating a curved bore. Compared to current standards, this method can be implemented in any installation regardless of the bore geome...

The geometric imperfections in high strength U-ing, O-ing and expanding (UOE) manufactured pipes are investigated in this paper using a high-resolution 3D surface scanner, and a reverse engineering and inspection software. The geometric analyses show that the initial imperfection patterns in the UOE manufactured pipes are not at all random, althoug...

Steel pipe elbow is a common feature in piping systems which is used to change the direction of a straight pipe. The Bourdon effect is the phenomenon of the elbows tending to straighten out when pressurized. Shemirani et al. (2014) studied the influence of the Bourdon effect on the ovalization developed in the elbows for fixed boundary conditions....

Steel Plate Shear Walls (SPSWs) are efficient and economical energy dissipating systems for buildings located in regions of high seismic risk. In spite of many benefits of SPSWs, however, their overturning stiffness is relatively low, especially in mid-to-high rise buildings. Therefore, there is a need for incorporating other structural elements in...

Due to the ease of fabrication and construction, gusset plate connections with single-sided splice members are a popular connection type in building frames and light structures. However, this detail produces local out-of-plane eccentricity, which can be detrimental to the ultimate strength of the connections. This paper presents experimental, numer...

1. Abstract This paper proposes a new method for determining pull forces required for the placement of steel or High Density Polyethylene (HDPE) pipe in Horizontal Directional Drilling (HDD) projects based on the large deflection beam theory. This method discretizes bore profile into straight and curved segments, and the tensile force increment alo...

In this article, ductile fracture on the tensile side of wrinkled cold bend pipes under monotonic combined loading condition is investigated through an experimental and analytical study. Two cold bend pipe specimens made of API X65 steel material were tested at the University of Alberta under increasing bending curvature with and without internal p...

Coped (notched) steel beams are widely used in steel frame structures. A state-of-the-art review on local failures of coped steel beams is presented with the main aim of providing a clear insight into the up-to-date research outcomes and design approaches on the issues of local web buckling, block shear, and fatigue. With a comprehensive review of...

Buried steel pipelines are one of the most efficient means of transporting oil and gas from their resource deposits to their markets. The pipeline industry is experiencing an increased demand for larger diameter pipelines along with the implementation of thinner walls and higher operating pressures. In these cases, the external pipeline loads have...

Cold bending is applied at locations where the pipeline direction has to be changed in a horizontal or vertical plane. The process of cold bending usually results in residual stresses as well as changes in the material properties at the vicinity of the cold bend location which makes the study of the mechanical behaviour of cold bends indispensable....

Pipelines can be subjected to significant amounts of tensile forces due to geotechnical movements like slope instabilities and seismic activities as well as due to frost heave and thaw cycles in arctic regions. The tensile strain capacity εtcrit of pipelines is crucial in the prediction of rupture and loss of containment capability in these load ca...

Elbows are used frequently in pipeline systems. Manufacturing of elbows tends to cause the primary circular sections to ovalize. Ovalization intensifies when elbows are subjected to internal hoop pressure. The total ovality in elbows comprises both manufacturing and pressurization ovality. Elbows with oval cross sections under internal pressure ten...

Pipe elbow is a common feature in pipelines and piping systems as a means to changing directions of otherwise straight pipelines. Irrespective of the processes involved in manufacturing pipe elbows, it is of interest to investigate whether they have any geometric imperfections. Researchers at the University of Alberta have devised a technique to me...

A revised analysis to derive the expression for the mode II interlaminar fracture toughness of fiber-reinforced polymers from internal notched flexure (INF) testing in small deformation is presented here. The approach adopted for the derivation takes into account the interlaminar shear load in the overhanging section outside the span. This improves...

The cold bended parts of pipelines are prone to geotechnical movements due to discontinuous permafrost, slope instabilities and seismic activities. Sen et al [1] carried out an extensive experimental study in 2006 in order to understand the buckling behaviour of cold bend pipes under applied curvature. In one of the experiments in this study, a hig...

This paper introduces a new test, method, named internal-notched flexure (INF) test, that is designed to measure the critical energy release rate of fibre-reinforced polymers for delamination growth in shear mode (mode II). The INF test generates stable delamination growth, with a monotonic increase of load and displacement in a nearly linear fashi...

Effect of bonded repair patch delamination on stress intensity factor (SIF) has been studied using finite element analysis (FEA) of cracked steel plates repaired with carbon fiber reinforced polymers (CFRP) patches. Two types of CFRP were used: sheet form, with elastic tensile modulus (EFRP) of 65 GPa; plate form, with EFRP of 165 GPa. Three sets o...

Performance-Based Plastic Design (PBPD) method is developed for the seismic design of ductile Steel Plate Shear Wall (SPSW) with moment resisting beam-to-column connections. In this method, pre-selected target drift and desirable yield mechanism of the plate walls are used as key performance criteria. The design base shear is obtained based on ener...

The use of high strength steel (HSS) pipes has increased in the past decades due to weight and cost reduction benefits. Cold forming processes, such as UOE, has become very popular due to its ease of pre-fabrication and mass production. The negative aspects associated with the cold forming of HSS pipes are the development of material anisotropy and...

Measurement of initial imperfections of energy pipes and incorporating them in analytical models has been a major focus of research in the pipeline industry as well as at the University of Alberta. Researchers at the University of Alberta have devised various techniques to measure initial imperfection of pipes prior to testing. The analytical imper...

Highly pressurized pipelines crossing harsh environments need to have two chief materials properties; they should have high strength in transverse direction to resist high operating pressers; and high deformability in the longitudinal direction to accommodate externally induced deformations. Pipeline producers try to deal with this dual demand in t...

The cold bend pipelines may be affected by the geotechnical movements due to unstable slopes, soil type and seismic activities. An extensive experimental study was conducted by Sen et al. in 2006 to understand the buckling behaviour of cold bend pipes. In their experiments, it was noted that one high pressure X65 pipe specimen failed under axial an...

The design of steel pipelines against longitudinal loading induced by soil movement and temperature requires an understanding of the strain demand induced by the environment in comparison with the strain resistance of the pipes. Girth weld flaws have been identified as the potential location of failure under longitudinal tensile strains due to bein...

The design equations for pipelines subjected to both internal pressure and longitudinal loading are based on the isotropic hardening plasticity model. However, high strength steel (HSS) pipelines exhibit plastic anisotropy, which cannot be incorporated in the traditional isotropic hardening plasticity model. The stress strain behaviors of HSS in th...

The material model proposed in Part I (Neupane , 2012, "Modeling the Deformation Response of High Strength Steel Pipelines-Part I: Material Characterization to Model the Plastic Anisotropy," ASME J. Appl. Mech., 79, p. 051002) is used to study the deformation response of high strength steel. The response of pipes subjected to frost upheaval at a pa...

Fatigue performance of coped steel beams, repaired with two forms of carbon fibre reinforced polymers (CFRP), was studied experimentally. The two forms included: fabric form, with elastic tensile modulus of 70.9 GPa; plate form, with elastic tensile modulus of 165 GPa. The CFRP was applied on a 10 mm fatigue crack at the cope location and the beams...

As the development and application of fiber reinforced polymer (FRP) composite materials to different engineering structures are increasing gradually, composite fiber patching techniques are being considered as alternatives to traditional methods of strengthening and fatigue crack repair in steel structures, such as the boom members of draglines. I...

Many bridges were built in Alberta after World War II with type G-girder precast concrete elements. Today, there are approximately 1500 G-girder bridges still in service all over the province. These bridges are typical short span (approximately 6 m long), simply supported, and without shear keys between girders. Structural deficiency of the G-girde...

This paper reviews the different shear design methods found in the literature for reinforced concrete beams strengthened externally with fibre reinforced polymer (FRP) sheets and compares the adequacy of each method by using the test results from the University of Alberta. The FRP shear design methods presented include the effective FRP strain and...

A large number of precast prestressed concrete multi-girder bridges were constructed in Alberta in the early 1960s. Major benefits of this type of construction included the elimination of the cast in place concrete bridge deck and the accelerated pace of construction in erecting the bridge. However, after providing 10 to 20 years of service, some o...