Severe Loading Conditions Research Articles

Optimized machine learning approaches for the prediction of viscoelastic behavior of modified asphalt binders

Additives are commonly used in pavement engineering to improve the original bitumen's rheological and mechanical characteristics to meet severe loading and climatic condition requirements. To select the optimum dosage of an additive for modifying the original bitumen, it is essential to predict the viscoelastic behavior of modified bitumens, which can be performed by implementing the constitutive viscoelastic parameters of the complex shear modulus (G*) and phase angle (δ). In this work, a comprehensive experimental database consisting of the results of the frequency sweep mode of a dynamic shear rheometer (DSR) at seven test temperatures (−22 ~ 22 °C) was used. Prediction models for the viscoelastic behavior of bitumen modified with different dosages of crumb rubber, styrene–butadienestyrene (SBS), and polyphosphoric acid (PPA) were developed by optimizing and applying different machine learning approaches, including Artificial Neural Networks (ANN), Robust Linear Regression, Linear Support Vector Regression, Decision Tree Regression, Gaussian Process Regression (GPR), and Ensemble Regression, on the data. By comparing the various studied model outputs in terms of performance measurements, such as the correlation of coefficients, relative root mean square error, scatter index, relative error, and Nash-Sutcliffe efficiency coefficient, it was determined that the Ensemble Regression method has the highest performance in predictions.

Improved efficiency maximization strategy for vehicular dual-stack fuel cell system considering load state of sub-stacks through predictive soft-loading

The durability of vehicular fuel cells can be affected by severe load conditions, such as ultrafast loading, frequent start/stop and idling/open-circuit operation. Currently, some fuel cell systems are developed based on dual-stack configuration. For dual-stack systems, not only the system efficiency, but also the load state of sub-stacks is crucial when determining the power distribution between sub-stacks. This study proposes an improved overall efficiency maximization strategy (I-OEMS) that combines a predictive soft-loading method to improve the load state of sub-stacks while ensuring the approximate maximum efficiency. Firstly, a conventional overall efficiency maximization strategy (C-OEMS) is formulated to analyze the load state and possible degradations of sub-stacks under dynamic driving cycles. Then, the proposed I-OEMS is developed accordingly, in which the short-term reference power of sub-stacks is pre-planned according to look-ahead vehicular demand power predicted by an iterative learning framework. Finally, simulations are conducted to analyze the effectiveness. The results show that I-OEMS can effectively limit the loading speed, reduce the start/stop frequency, and operate the auxiliary sub-stack away from idling/open-circuit, so as to enhance the durability. Furthermore, it achieves a better fuel economy compared with simply limiting the loading rate of sub-stacks under C-OEMS, especially for urban driving cycles.

INFLUENCE OF BOND AND FRICTION ON TENSILE STRENGTH OF PERFORATED STEEL PLATE CONNECTOR UNDER CONFINEMENT

Concrete-filled steel tube (CFST) columns are commonly used in Japan, which utilize onsite full-strength welded splices between columns. However, onsite welding requires high technical skill and a controlled environment. Further, this type of splice is expensive and, in most cases, is not necessary for dependable building performance under severe earthquake loading conditions. Recently, new types of CFST column splices have been developed that enhance constructability and avoid the need for onsite welding. In the proposed column splice method, perforated steel plates are placed on each column half and are welded into place. To evaluate the performance of this splice, it is important to determine the pull-out strength and behavior modes of the perforated steel plates embedded into the CFSTs. In this paper, a pull-out experiment with perforated steel plates embedded into a square CFST stub is conducted. The experimental parameters are the bond between the steel plate and the concrete, the embedded length of the perforation, and the extra length of the steel plate. The effect of the bond and friction strength between the steel and concrete are discussed, and a design formula for the pull-out strength of the perforated steel plate is examined.

Thermally Sprayed Nickel-Based Repair Coatings for High-Pressure Turbine Blades: Controlling Void Formation during a Combined Brazing and Aluminizing Process

Turbine blades must withstand severe loading conditions and damage can occur during operation due to heat, pressure, foreign objects and hot gas corrosion, despite the protective coatings applied onto the turbine blades. Instead of replacing the damaged components, maintenance, repair and overhaul are key to extend the total service life. Besides welding, the repair of turbine blades by brazing is an established repair process in the industry and involves many individual steps that often require a high degree of manual work. In the present study, a hybrid joining and coating technology was developed to shorten the state-of-the-art process chain for repairing turbine blades. With this approach, a repair coating, which consists of a filler metal, a hot gas corrosion protective layer and an aluminum top layer, is applied by atmospheric plasma spraying. The coated turbine blade then undergoes a heat-treatment so that a brazing and aluminizing process is carried out simultaneously. Due to diffusion and segregation processes, pores can occur in the heat-treated coating. In the present study, a full factorial design of experiment was performed to reduce the pores in the coating. The microstructure of the repair coating was investigated by optical- and scanning electron microscopy (SEM), and the impact of the process parameters on the resulting microstructure is discussed.

Finite element analyses of improved lateral performance of monopile when combined with bucket foundation for offshore wind turbines

A wide-shallow bucket is connected to a monopile for offshore wind turbines to withstand the severe loading conditions in marine environments and this innovative pile-bucket foundation has not been investigated comprehensively. In this paper, a monopile, wide shallow mono-bucket and pile-bucket were firstly tested under lateral loading via geotechnical centrifuge to examine the performance of the hybrid foundation. The results of the centrifuge tests and extensive finite element analyses with dimensions of an actual wind turbine foundation show that the addition of the bucket significantly enhances the lateral bearing capacity and stiffness of the monopile in both sand and soft clay. The load transfer mechanism, failure mode and bearing behavior are illustrated to study how the bucket and pile component contribute to the performance of the foundation system and the interactions of the pile-soil-bucket. Finally, parametric studies about the loading eccentricity and geometry of the bucket are carried out to provide references for the engineering practice.

Specific Modeling Issues on an Adaptive Winglet Skeleton

Morphing aeronautical systems may be used for a number of aims, ranging from improving performance in specific flight conditions, to keeping the optimal efficiency over a certain parameters domain instead of confining it to a single point, extending the flight envelope, and so on. An almost trivial statement is that traditional skeleton architectures cannot be held as a structure modified from being rigid to deformable. That passage is not simple, as a structure that is able to be modified shall be designed and constructed to face those new requirements. What is not marginal, is that the new configurations can lead to some peculiar problems for both the morphing and the standard, supporting, elements. In their own nature, in fact, adaptive systems are designed to contain all the parts within the original geometry, without any “external adjoint”, such as nacelles or others. Stress and strain distribution may vary a lot with respect to usual structures and some particular modifications are required. Sometimes, it happens that the structural behavior does not match with the common experience and some specific adjustment shall be done to overcome the problem. What is reported in this paper is a study concerning the adaptation of the structural architecture, used to host a winglet morphing system, to make it accomplish the original requirements, i.e., allow the deformation values to be under the safety threshold. When facing that problem, an uncommon behavior of the finite element (FE) solver has been met: the safety factors appear to be tremendously dependent on the mesh size, so as to raise serious questions about the actual expected value, relevant for the most severe load conditions. On the other side, such singularities are more and more confined into single points (or single lines), as the mesh refines, so to evidence somehow the numerical effect behind those results. On the other side, standard engineering local methods to reduce the abovementioned strain peaks seem to work very well in re-distributing the stress and strain excesses to the whole system domain. The work does not intend to give an answer to the presented problem, being instead focused on describing its possible causes and its evident effects. Further work is necessary to detect the original source of such inconsistencies, and propose and test operative solutions. That will be the subject of the next steps of the ongoing research.

Self-Similar Characteristics of COVID-19 Patient arrival at Healthcare Centre – A Study Using Queuing Models

The entire world is spreading of coronavirus-COVID-19 has increased exponentially across the globe, and still, no vaccine is available for the treatment of patients. The crowd has grown tremendously in the hospitals where the facilities are minimal. The queue theory is applied for the Single-server system and its self-similarity existence in a queue used to identify the queue time, waiting time, and Hurst parameter by different patient arrivals methods Health care center in our local area located in Hosapete, Ballari district, Karnataka. Due to more arrivals to the health care center for the identification and confirmation of disease covid-19. This study paper presents a sequential queuing model for estimating infections' detection and identification in severe loading conditions. The goal is to offer a simplified probabilistic model to determine the general behavior to predict how long the treatment cycle will diagnose and classify people already tested and get negative or positive results. For this type of Method, there are some graphical representations of the various measurement criteria. The modelling results showed that the patient's waiting period in the course of inquiries, detections, detecting, or treating COVID-19 in the event of imbalances in the system as a whole rise following the logarithm rule.

Environmental impact and effect of chemical treatment on bio fiber based polymer composites

In recent years, bio fibers (such as jute, hemp, flax, nettle, etc) are gaining more attention due their light weight, high specific strength, biodegradability, etc in various applications. Along with this, environmental issue is also an important aspect for maintaining sustainability of the bio fiber based composites. Failure occurs in bio fiber based polymer composites when they are applied to severe loading conditions and the material start degrading. To sustain the lifetime of the bio fiber composites, chemical treatment of the bio fiber is done to enhance the mechanical strength between the bonds so that the amount of stress transferability in the composites is equalized. The most important chemicals sources for the treatments are alkaline, silane, acetylation, benzoylation, acrylation, maleated coupling agents, permanganate, peroxide, isocyanate, stearic acid, sodium chlorite, triazine, derivatives of fatty acids (oleoyl chloride). The present study summarises the studies carried out on the environmental impact and various chemical treatments that were applied to bio fibers for enhancing their properties.

Investigation of the Tribological Properties of Different Textured Lead Bronze Coatings under Severe Load Conditions

The purpose of this paper is to investigate the variation in the coefficient of friction (CoF) and also the wear in a lead bronze coating under different texture conditions. The tribological tests were performed using a tribometer with pin on disk configuration. Several kinds of textures, realised by a surface laser texturing, were tested by varying the diameter, depth, and density of the dimples under severe working conditions. The innovative aspect concerns the behaviour of the textured lead bronze coating and the lubrication conditions when the sample is subjected to extreme load conditions. Confocal microscopies and SEM (Scanning Electron Microscopy)/EDS (Energy Dispersive X-Ray Spectroscopy) analyses were performed to evaluate the texture behaviour and also the surface deterioration of the coating. The results show that the application of texture processing leads to an improvement in the tribological properties of the coating. By analysing separately the variation of the different geometric parameters of the dimples, it has been shown that the best results are obtained with a diameter of 50 μm, a density of 5%, and a depth of 5 μm.

Heavy Vehicles Brake Drums — An Accurate Evaluation on Thermal Loads in Severe Service Conditions

Heavy vehicles service brakes are subject to severe loading conditions that can exceed the design conditions of safe operating performance in critical situations. Materials are prone to lose their design properties at high temperatures. Since the function of brakes is to convert the vehicle kinetic energy into heat by friction, temperature is the main variable to be considered, due to the fade of the linings composite material and cast iron drum deformation. The intent of this work is to evaluate the thermal loads of brake drums, when subjected to severe service conditions, in order to allow further analyses, mainly related to their dimensional and form variation. A case study is described, showing the possibility of the development of high temperatures and consequent risk of accidents in a real long downhill descent. Experimental data were preferably used to assure higher accuracy to the analysis. In the authors’ further work, a FEA simulation will be conducted with the data supplied in the present paper.

High Strength Corrosion Resistant Steel for Aircraft Landing Gears and Structures

<div class="section abstract"><div class="htmlview paragraph">High stressed aircraft landing gear and structural components are subjected to severe loading, corrosion and adverse environmental conditions. Materials such as high strength steels and high-strength titanium alloys are widely used for those critical components. The main criterions for choosing the materials are their strength and fatigue strength, toughness and ductility.</div><div class="htmlview paragraph">300M steel is widely used for high stress aircraft landing gears and structures; however, this steel is not corrosion-resistant and requires protective coatings.</div><div class="htmlview paragraph">Cobalt-free, quenched and tempered high strength corrosion resistant steel alloy (“HSCR steel”) provides the same strength, ductility, and toughness as the 300M steel and while it possesses corrosion resistance in salt spray test. HSCR steel has showed no rust after the standard salt spray test in accordance with ASTM B117 using a 5% NaCl concentration, natural pH, at 95°F, for 200 hours test duration.</div><div class="htmlview paragraph">Aircraft applications of the wrought HSCR steel include landing gear components, rotatable shafts, actuators, flap tracks, slat tracks, fasteners, and others.</div><div class="htmlview paragraph">Besides forging, the aircraft components can be manufactured from HSCR steel powders by:<ul class="list disc"><li class="list-item"><div class="htmlview paragraph">Powder metallurgical-based hot isostatic pressing (PM HIP) to the near net shapes</div></li></ul></div><div class="htmlview paragraph">(NNS) followed by finish machining/surface finishing and heat treatment<ul class="list disc"><li class="list-item"><div class="htmlview paragraph">Additive manufacturing (AM) followed by surface finishing and heat treatment.</div></li></ul></div><div class="htmlview paragraph">Modification of the HSCR steel is applicable for vacuum and investment casting of aircraft hydraulic fluid system, motion control and actuation system, cargo system, and flight safety components.</div><div class="htmlview paragraph">HSCR steel is a low cost alternative of Ti-6Al-4V alloy. The components made from Ti- 6Al-4V alloy can be substituted by the same weight components made from HSCR steel due to HSCR steel possesses slightly higher specific stiffness and specific strength (ratio of modulus elasticity and ultimate tensile strength to density) and slightly lower ductility and toughness compared to Ti-6Al-4V alloy.</div><div class="htmlview paragraph">Industrial production of HSCR steel is underway.</div></div>

Analytical Modeling and Vibration Analysis of the Last-Stage LP Steam Turbine Blade Made of Functionally Graded Material

The conventional materials used in steam turbine blades undergo severe environmental loading conditions resulting in corrosion, fatigue failures, and several kinds of defects. Especially for the last-stage steam turbine blade, there is a need to employ hybrid materials such as functionally graded (FG) materials or other composites that combine the properties of two or more desired materials to withstand extreme conditions without much loss of blade output. The present paper includes the theoretical investigation of free vibration study of the regular last-stage low-pressure steam turbine blade using the Finite element method via the in-house codes. Further, the structural modeling of the functionally graded blade and its free vibration characteristics are evaluated. The dynamic equations of motion of the functionally graded blade are derived by considering geometric taper. The impact of several factors, such as the volume fraction index, rotational speed, and twist angle on the natural frequencies of the FG rotating blade, is reported at different speeds of operation. It is observed that with an increase in volume fraction index, both chordwise and flapwise bending frequencies decrease; however, the rate of decrease is higher in higher modes. The opposite trend is observed in the FG blade’s vibratory characteristics with respect to the rotational speed and twist angle.

Thermal stability enhancement of ultrathin Ag film electrodes by incorporating atomic oxygen

The structural deformation of a continuous thin film to discrete nanoscopic particles due to solid-state thermal dewetting has been considered an inevitable consequence of using ultrathin Ag films under severe thermal and electrical loading conditions. Thermal dewetting diminishes the electrical and optical performance of Ag film electrodes. Herein, a highly smooth, less defective, completely continuous ultrathin Ag film was used to prove the effectiveness of the atomic O-mediated Ag growth mode in suppressing thermal dewetting. The strong O interference at the outermost surfaces of the Ag nanoscopic geometries provided morphological perfection and chemical modification that contributed to the suppression of the migration of thermally activated Ag atoms. The alleviation of thermal dewetting could be attributed to the reduction in free energies because of the incorporation of the minimal amount of oxygen atoms into interstitial Ag lattice sites without forming oxide phases. The ultrathin (4.5 nm) Ag films sandwiched between thin ZnO films maintained a strong structural integrity and high electrical endurance by successfully circumventing thermal dewetting after exposure to high annealing temperatures up to 673 K and under heavy voltage loading conditions. This facilitated the integration of the heat generating and saving functions, while maintaining optical transparency.

Numerical Analysis of Shallow Tunnels Under Static Loading: A Finite Element Approach

In the present world, the need for underground structures has grown many folds due to the increasing population, the advancement of public infrastructure, and the scarcity of land. Underground structures also provide attractive alternatives for storage of explosives and other military hardware. Being at shallow depth, their potential impact on the environment and surrounding structures can be significant. Therefore, it is crucial to understand the surrounding material behaviour for the safe and economical design of underground facilities. In the present work, an attempt is made to simulate the in situ condition using finite element, which has been validated by experimental results, to understand the tunnel deformation behaviour under static loading condition in soft rocks. 3D non-linear finite element analysis has been carried out by using Abaqus. Rockmass-tunnel model considered in this study has dimensions of 30 cm × 30 cm and 35 cm. The diameter of the tunnel has been varied from 2.5 cm, 3.5 cm to 5.0 cm. Similarly, the overburden depth is taken as 2.5 cm, 3.5 cm and 5.0 cm. Both the lined and unlined cases of the tunnel have been considered. Geo-material has been prepared in the laboratory having four different compositions of POP, sand, clay and mica. The weathering effect of the rockmass is also considered in the study. Fresh, slightly weathered, medium weathered, and highly weathered are the four different weathering stages of basalt rock taken into consideration. The elasto-plastic behaviour is considered for the natural and synthetic rock, and a Mohr–Coulomb constitutive model is incorporated. Stress and deformation behaviour is monitored for different rocks and geo-materials. Longitudinal and transverse profiles of the tunnel have been plotted to understand the response of tunnel lining and the surrounding rockmass, along and across the point of loading. The paper concludes that the diameter of the tunnel, overburden depth of the tunnel, and weathering of rock has a significant effect on the stability of tunnels under severe loading conditions.

Integrating material properties from magnetic resonance elastography into subject-specific computational models for the human brain

Advances in brain imaging and computational methods have facilitated the creation of subject-specific computational brain models that aid researchers in investigating brain trauma using simulated impacts. The emergence of magnetic resonance elastography (MRE) as a non-invasive mechanical neuroimaging tool has enabled in vivo estimation of material properties at low-strain, harmonic loading. An open question in the field has been how this data can be integrated into computational models. The goals of this study were to use a novel MRI dataset acquired in human volunteers to generate models with subject-specific anatomy and material properties, and then to compare simulated brain deformations to subject-specific brain deformation data under non-injurious loading. Models of five subjects were simulated with linear viscoelastic (LVE) material properties estimated directly from MRE data. Model predictions were compared to experimental brain deformation acquired in the same subjects using tagged MRI. Outcomes from the models matched the spatial distribution and magnitude of the measured peak strain components as well as the 95th percentile in-plane peak strains within 0.005 mm/mm and maximum principal strain within 0.012 mm/mm. Sensitivity to material heterogeneity was also investigated. Simulated brain deformations from a model with homogenous brain properties and a model with brain properties discretized with up to ten regions were very similar (a mean absolute difference less than 0.0015 mm/mm in peak strains). Incorporating material properties directly from MRE into a biofidelic subject-specific model is an important step toward future investigations of higher-order model features and simulations under more severe loading conditions. Statement of SignificanceThe study presents a method to calibrate and evaluate subject-specific finite element brain models using a combination of advanced magnetic resonance imaging (MRI) data. The imaging data is acquired in human volunteers and includes anatomical MRI, magnetic resonance elastography (MRE), and tagged MRI to generate subject-specific geometry, calibrate subject-specific material properties, and evaluate simulation response using subject-specific brain deformation. This dataset of MRE and tagged MRI allows for a unique evaluation of whether material properties from MRE can be used to create biofidelic computational models of the human brain. The study develops a calibration procedure to readily calculate linear viscoelastic material parameters from MRE data and then provides a sensitivity study of the effect of mechanical heterogeneity of the brain on simulation response. The calibrated computational models are used to simulate each subject's tagged MRI experiment; the results show good agreement between the simulated and experimental strain fields. The presented study and results will be informative in guiding the calibration of subject-specific computational brain model from experimental MRE data. The processed MRI, MRE, and tagged MRI data are publicly available at https://www.nitrc.org/projects/bbir/.

Natural ingredients based environmental friendly metalworking fluid with superior lubricity

Mineral oil-based metalworking fluids (MWFs) are hazardous for human and environmental health. This highlights the need for the development of environmental-friendly MWF (oil-in-water emulsion). The solution can be explored through the use of natural products as ingredients to formulate the environmental-friendly MWF. The natural products used in present MWF formulation include soybean oil, water, and gum acacia. The concentration of gum acacia (natural emulsifier) is optimized through surface/interfacial energetics using Goniometer. The frictional responses are recorded using Four-ball-tester (FBT). Tribological response of the formulated metalworking fluid (FF) is benchmarked with that of commercial fluid (CF). The results indicate that the FF is much better than CF under severe loading conditions. The improved frictional characteristics for FF are attributed to pressure and temperature assisted activation of natural emulsifier molecules. This activation leads to chemisorption of emulsifier molecules to the tribological contact, aiding the tribology.

Comparison of Biomechanical Parameters between Medial and Lateral Compartments of Human Knee Joints

Background: The knowledge of biomechanics helps in predicting stresses in different parts of the knee joint during daily activities. Objective: The objective of this study is to evaluate the biomechanical parameters of the knee joint, such as contact pressure, contact area, and maximum compressive stress, at full extension position during the gait cycle. Methods: The three-dimensional finite element models of human knee joints are developed from magnetic resonance images (MRI) of multiple healthy subjects. The knee joints are subjected to an axial compressive force of 1150 N at full extension position. Results: The maximum compressive stresses on the medial and lateral tibial cartilages were 2.98±0.51 MPa and 2.57±0.53 MPa, respectively. The maximum compressive stresses on the medial and lateral menisci were 2.81±0.92 MPa and 2.52±0.97 MPa, respectively. The contact area estimated on medial and lateral tibial cartilages were 701±89 mm2 and 617±63 mm2, respectively. Conclusion: The results were validated using experimental and numerical results from literature and were found to be in good agreement. The magnitude of maximum compressive stress and the contact pressure was found to be higher at the medial portion of the cartilages as compared to that in the lateral portion of the cartilages. This study shows that the medial meniscus is more prone to tear under severe loading conditions, as the stresses in the medial meniscus are higher than that in the lateral meniscus. The total contact area in the medial tibial cartilage is larger than that in the lateral tibial cartilage.

Unmanned Aerial Vehicles in Modern Power Systems: Technologies, Use Cases, Outlooks, and Challenges

The electricity network is a very large-scale and widely distributed system that is highly interdependent with other large infrastructure systems (e.g., natural gas, telecommunication, water and wastewater, and transportation). Power grids are being stressed by severe loading conditions caused by the rising electrification of infrastructure (e.g., in creasing the use of electric vehicles) as well as the overall growth in world population and electricity usage. Any prolonged electricity interruptions can have a widespread effect on other systems, including disruptions in Internet and security equipment, traffic and street lights, pumping stations and public transportation, home appliances and tall building elevators, large industrial equipment and hospital devices, water supplies and natural gas delivery networks, and so on.

Special Considerations for Well Tubular Design at Elevated Temperatures

Summary Understanding of material properties for tubular design under high-pressure/high-temperature (HP/HT) conditions goes well beyond the basics of the classic methods routinely used in the industry. Coupon test results of high-strength tubulars commonly used in HP/HT wells are presented to demonstrate the temperature and strain-rate dependencies of the stress-strain response. Based on the coupon test results, analytical equations and advanced nonlinear Finite Element Analysis (FEA) are used to illustrate the substantial impact that the temperature and rate-dependent material properties have on pipe body and connection performance in HP/HT applications. This paper raises an awareness of the importance of strain-rate effects, and recommendations are made on a few special considerations to account for these effects in well tubular design for elevated temperature applications. In addition, the findings also provide the basis for a critical discussion of the applicable American Society for Testing and Materials (ASTM)/American Petroleum Institute (API) test standards and the need to understand the effect of different strain/loading rates that may be used in material characterization and full-scale testing of tubular products at elevated temperatures. Collectively the information and results presented in the paper are expected to be very useful to the new generation of engineers charged with the tubular design for challenging well applications involving elevated temperature and severe load conditions.

Numerical simulation of the mechanical behaviour of steel pipe bends under strong cyclic loading

The present study uses advanced numerical tools to examine the mechanical behavior of steel pipe bends (elbows), subjected to strong cyclic loading, associated with repeated plastic deformations of alternate sign. The elbows are modeled with finite elements, accounting for the measured elbow geometry and the actual properties of steel elbow material. The main feature of the present work is the simulation of material response using an advanced cyclic-plasticity model, based on the bounding-surface concept, implemented through an in-house material subroutine. Upon appropriate calibration with material tests in strip specimens, extracted from the bends under consideration, the constitutive model is employed for predicting the mechanical response of large-scale physical laboratory experiments. Very good predictions are obtained in terms of global load-displacement response, as well as in terms of local strains and their accumulation over the loading cycles (ratcheting) at specific elbow locations. This indicates that the bounding-surface model can be an efficient tool for predicting accurately the mechanical response of piping components under severe cyclic loading conditions. Finally, using the validated numerical models, extensive results are obtained, focusing on the effects of internal pressure on strain accumulation at specific locations of the elbow, for three values of pipe thickness.