The collapse behavior of axially compressed cone-cylinder transition with single load indentation (SLI) imperfection through experimental and numerical approaches is presented in this paper. A total of six (6) cone-cylinder transitions were manufactured from 0.5 mm steel plate. Four models were manufactured in pairs for perfect and imperfect cone-cylinder with indentation amplitude of 0.56 mm. While

Herein, a tensile test for notched round–bar specimens of two types of carbon steel used in nuclear containment vessels was performed. The test results were analyzed using the Bridgman solution and an elastoplastic finite element method. The analyses showed that ductile failures in the tensile state were initiated when the sum of equivalent and mean stresses reached a critical value of the material

One of the most important issues in design of water tube boilers is the prediction of the critical heat flux and the corresponding critical quality of the steam and vice versa. This phenomenon directly affects growth rate of oxide/deposit layers, rising water wall tubes temperature, and consequently tubes burnout. In the present work, the critical situations in a furnace of a subcritical drum boiler

This paper proposes the temper bead welding (TBW) technique as an alternative to post-weld heat treatment (PWHT) by varying the polarity between the deposited layers while other welding variables remain the same. The work was conducted to study the effect of changing welding polarities using the shielded metal arc welding (SMAW) process on microstructure, microhardness, grain size, weld bead geometry

Available limit load solutions for plates containing embedded cracks in R6 and BS7910, a newly published global solution by Lv et al. and a new local solution recommended in this paper are validated via the reference stress J scheme using 612 finite element J cases (see Part I). The results show that the Lv et al. global limit load solution, the R6 global solution and the BS7910 reference stress solution

Two different thermo-mechanical controlled process procedures were utilized to modify the microstructure and texture of pipeline steel. Moreover, electrochemical hydrogen charging and hydrogen permeation experiments were used to investigate the effect of texture and microstructure on the HIC susceptibility of tested specimens. The results showed that different used TMCP parameters did not change the

This paper investigated the two-phase cross-flow-induced vibration of the tube bundles considering the effects of the tube support structure. A mathematical model of the tube bundles subjected to two-phase flow and the clearance restriction was developed. Based on this model, the vibration responses and bifurcation diagrams of the tube bundles in 20%, 40%, 60%, and 80% void fractions were calculated

In this paper, the stress response characteristics of a straight hydraulic pipe subjected to random vibrations were studied. The motion equation of the straight hydraulic pipe subjected to random vibration was established by utilizing the finite element method (FEM), and considering the fluid-structure interaction (FSI). The discrete analysis method was employed to solve the motion equation of the

In this paper, the thermo-elasto-plastic behavior of a thick walled cylindrical shell made of a Functionally Graded Material (FGM) is analyzed by Successive Approximation Method (SAM). The FGM ingredients include Aluminum and Silicon Carbide in which the effective material properties are estimated using the Modified Rule of Mixture. The shell is subjected to a combination of internal pressure and temperature

A numerical simulation study explores the effects of initial defects on the collapse strength of pipelines under external pressure, with a focus on the coupling effect of multiple initial defects. The collapse strength of pipelines with only one initial defect is studied and the effects of the length and amplitude of the defect are determined. Then, pipelines with multiple initial defects are analysed

In this two-part paper, guidance for assessing plates containing embedded elliptical cracks under complex loading conditions is developed, based on the fracture mechanics validation of the limit load solutions using the finite element (FE) J solutions. In Part I of this paper, elastic-plastic 3D FE analyses are performed for plates with embedded off-set elliptical cracks under combined biaxial stresses

The fluid hammer phenomenon is a devastating incident that can cause substantial damages to the hydraulic systems. If the fluid reaches the vapor pressure due to high pressure gradients, the phenomenon is called column separation. In this study, the overpressures and the column separation induced by the sudden closure of the valve are studied experimentally. To this end, an experimental apparatus consisting

This study focuses on the dynamic behavior of a cantilevered fluid conveying hybrid pipe (FCHP) consisting of two different materials (aluminum and steel), and resting on a two-parameter elastic soil. To analyze the fluid-structure interaction in a hybrid pipeline conveying fluid, the pipe was modeled as an Euler-Bernoulli beam, and the equation of motion that describes the behavior of the dynamics

Despite being considered the safest means to transport oil and gas, pipelines are susceptible to degradation. Pipeline integrity management (PIM) is implemented to lower the risk of failure due to degradation and to maintain the functionality and safety of pipelines. PIM consists of a set of activities for assessing the operational conditions of pipelines. These activities generate data with high volume

P92 steel (10Cr9MoW2VNbBN) is widely used in high-temperature steam piping and high-temperature header fabrications of ultra-supercritical units. In this paper, a follow-up study on the microstructure, mechanical properties and life of P92 steel steam pipes which are virgin, 31,000 h in service, 49,000 h in service and 71,000 h in service was carried out. The results show that the mechanical properties

The burst pressures of large diameter-to-thickness ratio thin-walled cylinders constructed of steel exhibiting a yield plateau were evaluated experimentally, by finite element analyses (FEA), and by existing predictive equations. The good agreement between the predicted and experimentally measured burst pressures of three thin-walled tanks with a large diameter-to-thickness ratio of 342, demonstrates

Adopting analytic hierarchy process (AHP), the present study sought to establish a comprehensive evaluation model for the laboratory tested or exposed internal drilling coating systems based on five types of failure modes which were often observable and measureable; then, the model was verified by the test of electrochemical impedance spectroscopies (EIS). In so doing, the corrosion resistant performance

Intermittent flow is one of the most complex flow patterns in gas-liquid two-phase flow in pipelines. The leakage of pipeline intermittent flow poses a threat to the operating safety. In order to improve the application of acoustic method to gas-liquid two-phase leakage detection, the amplitude characteristics and propagation velocity of dynamic pressure wave of intermittent flow for gas-liquid two-phase

Stress intensity factors (SIF) of a nozzle corner crack in a pressure vessel subject to pressure and thermal loadings are evaluated using finite element method (FEM) and compared with the method described in ASME XI appendix G (2013 section XI). The formula in ASME XI appendix G is defined for the crack corner at a specific location of the nozzle/vessel connection which may limit the structural integrity

It is important to investigate the uncertainty of failure assessment models for safety management and reliability calculations of pipelines containing cracks. In this paper, firstly, we predicted the internal burst pressure of 250 sets of collected test data based on 7 failure assessment models and obtained the prediction accuracy (PA). Secondly, the correlation between the PA and the actual internal

The manuscript described the effect of Ni-based filler on microstructure and mechanical properties of the dissimilar welded ASTM A335 grade P22 and P91 alloy steel plate. The dissimilar welds joint (DWJ) was produced using the Gas Tungsten Arc Welding (GTAW) process. The DWJ was characterized for metallographic and mechanical testing for as-welded and post-weld heat treatment (PWHT) conditions. For

In this study the short-fiber thermoplastic polymer composite is proposed to produce a pressure vessel service equipment used for the transportation of chemicals and dangerous goods. Mechanical tests show nonlinear response of this composite, including initial elastic stage of loading. To address the stress analysis problem, the constitutive material model was proposed and calibrated to describe the

The present paper aims to predict distortions and residual stresses in thick plate weld joints of austenitic stainless steel material prepared by automatic hot wire gas tungsten arc welding (GTAW) process and narrow gap technique using finite element analysis (FEA). The prediction has been validated by carrying out experiments. The variables considered in welding of plate joints are narrow groove configuration

Fatigue test was executed to evaluate the fatigue performance on the fillet and butt weld joint of the natural gas branch pipe. Diameter of the branch pipe, throat thickness, geometrical shape of the fillet weld and welding processes were adopted to assess the fatigue strength of the branch pipe. SMAW and GTAW process were used to compare the welding process and the mechanical performance of the fillet

Nowadays, composite pipes, due to their unique properties such as high stiffness to weight ratio and excellent corrosion resistance, play a significant role in the industry. Composite pipes are usually loaded by internal hydrostatic pressure for a long time. Therefore, their long-term creep behavior has been considered as a severe issue. Although the experimental method is a reliable and standard studying

The through-thickness distribution of residual stress at weld toes and weld center lines was conducted and studied, which was the basic input parameter for engineering critical assessment (ECA) in BS 7910 Annex Q. A thermal-mechanical coupled welding residual stress simulation with/without repair welding of thick wall pipeline was carried out first. To further investigate the r/t ratio effect and heat

The design and evaluation of offshore structures’ piping systems subject to blast events are of significance and require advanced analysis approaches. They are important because during an explosion rupture of a piping and vessel system leads to the leakage or release of hydrocarbons which will likely cause another explosion. Advanced nonlinear analysis in time domain is required in order to agreeably

Constrained dents normally cause serious plastification on the pipe under internal pressure due to the restraint of the indenter. Therefore, in this work, the strain response of the API 5 L X80 (referred to as X80 in the remainder part) steel pipeline containing a constrained dent was investigated. Firstly, the formation process of the constrained dented pipeline was numerically simulated by establishing

Two steel pressure vessels, part of an air compressor unit, failed during hydrostatic test at a pressure lower than proof pressure. Pressure drop and fluid leakage was noted during the test and later investigation revealed through-wall cracks on the shells of each vessel. Experimental and numerical investigation was employed to determine possible causes of failure and to propose a repair method for

Small punch test offers unique capabilities in extracting material properties from a very small volume of material. This is an attractive prospect for measuring the properties of hazardous materials such as those in the nuclear industry. Although standards are being developed for formalising small punch test, the uncertainty associated with its results due to issues with misalignment, sample geometry

In this study, the effects of pre-tempering on microstructure, hardness, impact toughness and fracture modes of weld metals in 2.25Cr–1Mo-0.25 V heat-resistant steel were investigated. Four weld metals with as-welded, three different post welding heat treatments were chosen as the investigated materials. Optical Microscopy (OM), Scanning Electron Microscope (SEM) were used to evaluate the microstructures

Fatigue life prediction of engineering components is essential for safe operation of mechanical systems. Energy based models have attracted much attention due to the combined considerations of stress and strain behavior, especially in low cycle fatigue regime. In this work, a new plastic strain energy density (PSED) based life prediction model for notched components subjected to cyclic loading is proposed

In this paper, the effects of external random excitation on the dynamic characteristics of a hydraulic curved pipe are investigated. A random vibration motion equation of a curved pipe conveying fluid is determined using Hamilton's principle, in which the fluid-structure interaction (FSI) and the effect of shear deformation are taken into account. The finite element method (FEM) and discrete analysis

This paper deals with the vibration characteristics of rotating functionally graded circular cylindrical shells (FG-CS). The thickness of the shell varies linearly along the longitudinal direction. The material properties are graded continuously with a power law (P-FGM) in the radial direction and depend on the temperature. The system of motion equation is established by using the first-order shear

Uncertainty is prevalent in the creep resistance of alloys, where at elevated temperature and low pressure, rupture can range across logarithmic decades. In this study, a probabilistic continuum-damage-mechanics (CDM)-based model is derived to capture the uncertainty of creep resistance. To meet this objective, creep data for alloy 304 Stainless Steel is gathered. A constitutive model, “Sinh”, is calibrated

This work provides detailed analyses of creep behaviors considering the influence of geometry change for pipe bends under combined bending and internal pressure loads based on the finite element method (FE). A modified Karchanov‒Rabotnov (K‒R) equation for creep damage is used in the ABAQUS user defined material subroutine (UMAT) compiled by FORTRAN. Typical results of creep stress, damage, and deformation

Creep-cyclic plasticity and creep-fatigue damage interaction of a welded flange are studied considering both the thermo-mechanical load and the welding residual stress (WRS). The presence of WRS was found to have a minimal effect on the shakedown and ratcheting interaction curves, though the stress distribution changes considerably in the presence of WRS. The effect of WRS is predominant for the initial

Internal corrosion is recognized as a serious treat in offshore pipeline services which are supposed to transport vast quantities of oil and natural gases over many long and complicated subsea routes. This paper aims to present a new approach for reliability evaluation of pipelines against corrosion using finite element simulation. In this process the effective random variables are selected by an efficient

Recent research in thin-walled structures and steel structures has demonstrated that, in addition to internal forces and membrane stresses of shells, initial deformation and imperfection components should also be considered when calculating design cases. This paper presents a numerical analysis of a steel water tank with an initial deformation of the shell, which is used in an industrial plant for

There is much controversy surrounding using laboratory specimens to predict the fracture behavior of high-grade pipeline steel due to their different constraints. Since there is a lack of unified parameters to quantitatively characterize the constraint effects, a model for the transformation of crack arrest toughness between different specimens and pipes has not been formed. In order to solve this

Duplex stainless steel is a structural material that is highly used in nuclear power plants, especially in the reactor core components and pipelines. Long-term exposure of duplex stainless steel in a high-temperature working environment will cause thermal aging embrittlement. Material deterioration will affect the long-term reliability of nuclear power plants. In this work, we used two different ultrasonic

This study investigated the performance and external pressure–supporting capacities of egg-shaped shells fabricated through free hydroforming. Nine preforms (length: 256 mm; width: 178 mm) were fabricated from thin-walled stainless plates (nominal thickness: 0.86 mm), eight of which were internally bulged into egg-shaped shells at various hydroforming pressure levels. Their geometric properties were

In the present investigation, a detailed microstructure and mechanical behaviour study for P91 welded joint were investigated. The welded joint was produced using the Gas Tungsten Arc welding (GTAW) process with dissimilar Ni-based filler IN625 (ERNiCrMo-3). For microstructure characterization of the weld joint, optical microscopy and scanning electron microscopy were utilized. The effort was made

A potential connection between the residual stresses generated by a cladding operation, the thermal stresses generated during post weld heat treatment (PWHT), and the propensity for underclad cracking was investigated. As-deposited residual stresses were measured at ambient temperature, using the contour method and neutron diffraction. Measurements were performed in 20 mm thick steel substrates that

Gas tungsten arc welding (GTAW) is considered a well-established process in the manufacturing industry. Despite, certain challenges associated with high hardness of heat affected zone and cold cracking susceptibility of joints, are the main barriers for this process to be implemented successfully within high integrity structure. By using a combined procedure of experiments and modelling (response surface

This review article presents an overview of the dissimilar welded joint's microstructure and mechanical behavior. Dissimilar metal weldings are generally employed in high-pressure tubing/tubing-coupler assembly generally functional in subsea oil-gas production instruments and a wide range of geothermal plants and piping systems for subsea manifolds. Thus, dissimilar metal welding has an essential role

In order to determine the optimal design of a type I box-shaped pressure vessel with inner tension struts, an analytical and numerical approach has been performed. As such a pressure vessel has not been introduced in literature yet, the geometry is described in detail and the acting forces are analyzed first. The results of this analytical approach are used to define a reference design of the main

This paper presents the initial development of a high temperature life prediction method that accounts for the variability in the material properties of Grade 91 steel. The method accounts for material variability by fitting a variable 3-parameter Weibull distribution to experimental rupture data and accounts for the variability of creep deformation on the steady-state stresses via a Monte Carlo approach

In this paper, the fracture behavior of a pressure vessel involving a full circumferential wall crack at the inner surface is investigated by applying the axisymmetric model. By using the extended finite element method (X-FEM), the stress intensity factor is calculated and compared for the case of a crack in the Aluminum monolayer cylinder as well as when the composite coating is mounted on its outer

The transferability of continuum damage parameters for ductile fracture from CT specimen to pipe has been investigated for 316LN stainless steel. The authors have earlier established crack initiation stress and crack evolution energy as damage parameters for 316LN SS, based on coupled experimental and numerical analysis. Using these fracture parameters, XFEM crack growth simulations were carried out

The feasibility of a pressure vessel shape optimization is here investigated. An analytical procedure based on calculus of variations is used for the shape optimization of a naturally closed pressure vessel aiming at either minimizing the mass or maximizing the volume under structural integrity constraints. The obtained shapes are ellipsoids with variable thickness along the meridian. Such geometry

Offshore seawater systems are commonly manufactured using a monolithic copper–nickel alloy (90%Cu10%Ni). However, because of the high cost of this material, they have been replaced in some Brazilian oil and gas platforms by C–Mn steel pipes clad with a Ni–Cu alloy (70%Ni30%Cu, Monel 400®). Therefore, considering the complex transition zone (TZ) in dissimilar weldments and its influence on the performance

The present study uses the self-similar approach, developed by Pistiner (2020), for solving the water hammer equation during the process of valve closure in infinite long pipeline. The obtained solution shows that the transient flow in the pipeline is characterized by three zones: the “near zone” located near the closing valve and is characterized by a positive flow; the “far zone” in the pipeline

Most of reactor vessel internals (RVIs) have been constructed by austenitic stainless steels (ASSs) to support and protect core from high temperature coolant and radiation particles. However, if they are operated in the harsh environment for a long time, ASS materials may undergo significant changes in micro-structural features, macroscopic deformation and strengths due to age-related degradation mechanisms

The progressive loss of integrity of production tubing results from time- and space- variant degradation processes, mainly scale and corrosion. Due to the potential disastrous consequences of failure, it is necessary and required to manage the integrity of production tubing systems by means of inspections, monitoring and maintenance. However, there are substantial uncertainties associated with the