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Failure Mechanisms and Fatigue Life Prediction of Engineering Structures

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Mechanics of Materials".

Deadline for manuscript submissions: closed (20 May 2023) | Viewed by 27671

Special Issue Editors


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Guest Editor
INEGI, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
Interests: structural integrity; fatigue; fracture mechanics; structure analysis; probabilistic models
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Co-Guest Editor
Faculty of Mechanical Engineering, Department of Mechanics, Material Science and Engineering, Wrocław University of Science and Technology, Smoluchowskiego 25, 50-370 Wrocław, Poland
Interests: Fatigue damage; reliability analysis; fatigue crack growth theory; failure analysis of metal materials; Micromechanics of Materials; Multiscale Materials Modeling
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Fatigue caused by constant or time-varying cyclic loading represents one of the most important types of failures to which materials, structural components, and structures are subjected during service life that can finally result in a sudden and unexpected fracture. Fatigue life prediction of materials and structural details can be modeled by deterministic and probabilistic analyses. Fatigue damage in metals generally initiates near the surface and spreads perpendicularly to the loading direction; this behavior is linked to cyclic plasticity and isotropic mechanical properties. On the other hand, composites with a polymer matrix exhibit orthotropic mechanical properties, favoring far more complex fatigue damage than in metallic materials, including matrix cracking, delamination, fiber rupture and failure occurring in a synergic, cumulative and random manner. Normally, fatigue design codes use the S–N curves and Palmgren–Miner linear damage rule for assessing damage accumulation. Fatigue analysis through the use of local approaches, such as stress-, strain-, and energy-based methods, is used to assess the fatigue crack initiation phase. Fracture mechanics approaches are recommended to characterize the fatigue crack propagation phase by taking into account various aspects, such as defect sizes, geometries, material and structural properties, loading history and conditions, accessibility to detail and inspection methods. Reliability methods are also increasingly used in fatigue design and analysis, since, in many cases, there are uncertainties regarding the variables under study. Therefore, researchers and designers have many concerns about the fatigue phenomenon, which makes the subject of high interest to the scientific community.

The aim of this Special Issue is to provide the data, models, and tools necessary to assess the failure mechanisms and fatigue damage calculation of engineering structures and structural components under cyclic loadings, taking into account several environmental conditions, temperature, corrosion, etc., through the use of advanced mathematical, numerical and experimental techniques. Therefore, researchers are invited to provide original research and review articles that seek accurate and efficient failure analysis, fatigue damage evaluation and fatigue design, a fracture-mechanics-based approach, computer-aided structural integrity, etc.

Dr. José A.F.O. Correia
Prof. Shun-Peng Zhu
Dr. Grzegorz Lesiuk
Dr. Haohui Xin
Guest Editors

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Keywords

  • Structural integrity
  • Fatigue life prediction
  • Ultralow-, low-, high- and giga-cycle fatigue
  • Fatigue behavior modeling and simulation
  • Fracture mechanics
  • Fatigue crack growth
  • Probabilistic fatigue and fracture
  • Fatigue reliability
  • Fatigue life extension
  • damage evaluation and fatigue design
  • Failure analysis and case studies
  • Failure mechanisms
  • Prognostics and health management
  • Probabilistic physics of failure
  • Probabilistic modeling
  • Durability and damage tolerance
  • Uncertainty quantification and propagation
  • Performance degradation modeling and analysis
  • Failure/fatigue analysis of steel and composite structures in civil engineering
  • Failure/fatigue behavior of FRP structures in civil engineering
  • Influence of manufacturing processes on fatigue behavior
  • Structural integrity assessments accounting for fatigue
  • Applications and design codes (e.g., pressure vessels, metallic bridges, wind towers, offshore structures, etc.)

Published Papers (11 papers)

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Research

14 pages, 5483 KiB  
Article
Parametric Study of the Numerical Model of a Bolted Connection of Steel Structure for Photovoltaic Panels
by Damian Mrówczyński, Tomasz Gajewski and Tomasz Garbowski
Materials 2022, 15(19), 6794; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15196794 - 30 Sep 2022
Cited by 1 | Viewed by 1183
Abstract
In the face of the reality that unexpectedly mobilized the governments of most central European countries (including Poland), the development of renewable energy sources (RES) seems to be an important direction. Therefore, both wind parks and solar farms will be constructed at double [...] Read more.
In the face of the reality that unexpectedly mobilized the governments of most central European countries (including Poland), the development of renewable energy sources (RES) seems to be an important direction. Therefore, both wind parks and solar farms will be constructed at double speed for energetic independence. This urgency makes the market of producers of structures for mounting solar panels also need to adapt quickly to the new situation. New constructions adapted to quick assembly with the use of nutless screw connections seem to be one of the best solutions. These structures must not only be easy and quick to install but also durable, which makes the connections resistant to cyclical loads. The speed of assembly of the substructure can be achieved precisely with the help of nutless connections, but their durability should be carefully analyzed. This article presents parametric analyses of the numerical model of this type of connection. The selection of appropriate numerical models for simulation is of key importance in the fatigue strength analysis of bolted connections. This article investigates two different models used in numerical fatigue analyses performed in the Abaqus FEA and FE-Safe program, namely, traditional bolt with nut and innovative self-tapping nutless bolt. Extended parametric analyses of both numerical models were carried out, which ultimately allowed optimization of the fatigue capacity of the connection. Full article
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8 pages, 6366 KiB  
Article
Study on Nitrile Oxide for Low-Temperature Curing of Liquid Polybutadiene
by Ping Li and Xiaochuan Wang
Materials 2022, 15(9), 3396; https://0-doi-org.brum.beds.ac.uk/10.3390/ma15093396 - 09 May 2022
Cited by 1 | Viewed by 1367
Abstract
As a significant component of composite solid propellants, the cross-link alkenyl polymers need to cure at high temperatures and the current isocyanate curing systems are highly humidity sensitive. This paper presented a low-temperature curing method for a cross-linked polymer (polybutadiene) with stable wettability [...] Read more.
As a significant component of composite solid propellants, the cross-link alkenyl polymers need to cure at high temperatures and the current isocyanate curing systems are highly humidity sensitive. This paper presented a low-temperature curing method for a cross-linked polymer (polybutadiene) with stable wettability by using cycloaddition of the nitrile oxide of tetramethyl-terephthalobisnitrile oxide (TTNO) and the C=C group of liquid polybutadiene (PB). The TTNO was synthesized in four steps from 1,2,4,5-tetramethylbenzene and evaluated as a low-temperature hardener for curing liquid PB. To characterize the reaction ability of TTNO at 25 °C, the cross-linked rubber materials of various contents (8%, 10%, 12%, 14%, 16%) of curing agent TTNO were prepared. The feasibility of the curing method can be proved by the disappearance of the absorption peak of the nitrile oxide group (2300 cm−1) by FT-IR analysis. Contact angle, TG-DTA and tensile-test experiments were conducted to characterize the wettability, thermo-stability and mechanical properties of the obtained cross-linked rubber materials, respectively. The results showed that the curing agent TTNO could cure PB at room temperature. With the growing content of the curing agent TTNO, the tensile strength of the obtained cross-linked rubber material increased by 260% and the contact angle increased from 75.29° to 89.44°. Moreover, the thermo-stability performances of the cross-linked rubber materials have proved to be very stable, even at a temperature of 300 °C, by TGA analysis. Full article
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10 pages, 236 KiB  
Article
Maintenance and Inspection of Fiber-Reinforced Polymer (FRP) Bridges: A Review of Methods
by Long Tang
Materials 2021, 14(24), 7826; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14247826 - 17 Dec 2021
Cited by 10 | Viewed by 2760
Abstract
Fiber-reinforced polymers (FRPs) are materials that comprise high-strength continuous fibers and resin polymer, and the resins comprise a matrix in which the fibers are embedded. As the technique of FRP production has advanced, FRPs have attained many incomparable advantages over traditional building materials [...] Read more.
Fiber-reinforced polymers (FRPs) are materials that comprise high-strength continuous fibers and resin polymer, and the resins comprise a matrix in which the fibers are embedded. As the technique of FRP production has advanced, FRPs have attained many incomparable advantages over traditional building materials such as concrete and steel, and thus they play a significant role in the strengthening and retrofitting of concrete structures. Bridges that are built out of FRPs have been widely used in overpasses of highways, railways and streets. However, damages in FRP bridges are inevitable due to long-term static and dynamic loads. The health of these bridges is important. Here, we review the maintenance and inspection methods for FRP structures of bridges and analyze the advantages, shortcomings and costs of these methods. The results show that two categories of methods should be used sequentially. First, simple methods such as visual inspection, knock and dragging-chain methods are used to determine the potential damage, and then radiation, modal analysis and load experiments are used to determine the damage mode and degree. The application of FRP is far beyond the refurbishment, consolidation and construction of bridges, and these methods should be effective to maintain and inspect the other FRP structures. Full article
15 pages, 4581 KiB  
Article
Reliability Analysis for Unrepairable Automotive Components
by Dariusz Ulbrich, Jaroslaw Selech, Jakub Kowalczyk, Jakub Jóźwiak, Karol Durczak, Leszek Gil, Daniel Pieniak, Marta Paczkowska and Krzysztof Przystupa
Materials 2021, 14(22), 7014; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14227014 - 19 Nov 2021
Cited by 13 | Viewed by 1818
Abstract
The analysis of the reliability parameters of a technical object and the determination of the change in the reliability of the object over time, requires the knowledge of the functional characteristics and reliability parameters of the elements included in a system. On the [...] Read more.
The analysis of the reliability parameters of a technical object and the determination of the change in the reliability of the object over time, requires the knowledge of the functional characteristics and reliability parameters of the elements included in a system. On the basis of the failure data of the selected element of the object, in this case the vehicle, it is possible to determine the average working time to failure of the element and the appropriate form of distribution that characterizes the reliability and durability parameters of the tested element. The main purpose of the research presented in the article was to develop a method of assessing the reliability of an electronic component of a vehicle-a boot lid contactor. This paper also presents three possible methods of repairing the boot lid contactor (sealing the housing with adhesive with better way, replacing the element with a new one or the most time-consuming solution, changing the shape of the boot lid). The authors also decided to determine the reliability and cost parameters that will allow preventive replacement of this element. The tests were carried out on a fleet of 61 vehicles of the same model, but with different body structures. Contactor failures were reported in 41 cases, of which 29 were in the hatchback construction and 12 in the estate type. The analysis of the distribution selection for the tested part of the passenger car-the boot lid contactor-was performed using the Likelihood Value (LKV) test to determine the rank of distributions. Also the maximum likelihood (MLE) method was used to estimate the distribution parameters. The three-parameter Weibull distribution was the best-fitted distribution in both cases. It was clearly defined that one model of car with two different types of body have vastly different reliability characteristic. Based on the reliability characteristic and parameters, the appropriate preventive actions can be taken, minimizing the risk of damage, thus avoiding financial losses and guaranteeing an appropriate level of vehicle safety. Full article
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25 pages, 11216 KiB  
Article
Bending Fatigue Behaviour and Fatigue Endurance Limit Prediction of 20Cr2Ni4A Gear Steel after the Ultrasonic Surface Rolling Process
by Zhiyuan Wang, Yangfei Huang, Zhiguo Xing, Haidou Wang, Debin Shan, Fengkuan Xie and Jiming Li
Materials 2021, 14(10), 2516; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14102516 - 12 May 2021
Cited by 5 | Viewed by 1872
Abstract
To study the effect of the surface properties on the bending fatigue performance of heavy-duty gear steel, the authors of this paper used the ultrasonic surface rolling process (USRP) to strengthen 20Cr2Ni4A carburized gear steel. USRP is a novel technique in which the [...] Read more.
To study the effect of the surface properties on the bending fatigue performance of heavy-duty gear steel, the authors of this paper used the ultrasonic surface rolling process (USRP) to strengthen 20Cr2Ni4A carburized gear steel. USRP is a novel technique in which the ultrasonic technology is incorporated into the concept of conventional deep rolling. In this study, we illustrated how the surface properties and cross-section mechanical property influence the three-point bending fatigue life of the samples before and after USRP treatment. At the same time, the predicted failure probability-stress-number of cycles (P-S-N) curve was drawn, and the fatigue fracture was analysed. The results show that the fatigue limit increased from 651.36 MPa to 918.88 MPa after USRP treatment. The fatigue source is mainly from the sample interior or surface scratches, and the fatigue performance is positively correlated with the results of the material surface roughness, surface residual stress and surface hardness. At the same time, combined with the change in the phase structure, dislocation structure, residual stress and hardness of the cross section of the material, it is found that the USRP process turns the steel into a gradient material with five layers. Finally, the coupling mechanism between the ultrasonic surface strengthening deformation layer and the carburized layer of 20Cr2Ni4A carburized gear steel is presented, and the grain structure distribution diagram of the section of the 20Cr2Ni4A model after surface strengthening treatment was simulated. The mechanism that influenced the fatigue performance after USRP treatment is explained from the perspectives of the surface and cross section of the samples. Full article
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18 pages, 6230 KiB  
Article
Influence of Lateral Movement on Level Behavior of Adhesion Force Measured Repeatedly by an Atomic Force Microscope (AFM) Colloid Probe in Dry Conditions
by Ping Li and Tianmao Lai
Materials 2021, 14(2), 370; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14020370 - 13 Jan 2021
Cited by 12 | Viewed by 1817
Abstract
An atomic force microscope (AFM) was operated to repeatedly measure the adhesion forces between a polystyrene colloid probe and a gold film, with and without lateral movement in dry conditions. Experimental results show that the adhesion force shows a level behavior without lateral [...] Read more.
An atomic force microscope (AFM) was operated to repeatedly measure the adhesion forces between a polystyrene colloid probe and a gold film, with and without lateral movement in dry conditions. Experimental results show that the adhesion force shows a level behavior without lateral movement and with a small scan distance: the data points are grouped into several levels, and the adhesion force jumps between different levels frequently. This was attributed to the fact that when the cantilever pulls off the sample, the contact area of the sample is not exactly the same between successive contacts and jumps randomly from one to another. Both lateral velocity and material wear have little influence on level behavior. However, with a medium scan distance, level behavior is observed only for some measurements, and adhesion forces are randomly distributed for the other measurements. With a large scan distance, adhesion forces are randomly distributed for all measurements. This was attributed to the fact that the cantilever pulls off the sample in many different contact areas on the scanning path for large distances. These results may help understand the influence of lateral movement and imply the contribution of asperities to adhesion force. Full article
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18 pages, 18571 KiB  
Article
Static and Flexural Fatigue Behavior of GFRP Pultruded Rebars
by Michał Barcikowski, Grzegorz Lesiuk, Karol Czechowski and Szymon Duda
Materials 2021, 14(2), 297; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14020297 - 08 Jan 2021
Cited by 9 | Viewed by 2103
Abstract
This paper presents the experimental results of composite rebars based on GFRP manufactured by a pultrusion system. The bending and radial compression strength of rods was determined. The elastic modulus of GFRP rebars is significantly lower than for steel rebars, while the static [...] Read more.
This paper presents the experimental results of composite rebars based on GFRP manufactured by a pultrusion system. The bending and radial compression strength of rods was determined. The elastic modulus of GFRP rebars is significantly lower than for steel rebars, while the static flexural properties are higher. The microstructure of the selected rebars was studied and discussed in light of the obtained results—failure processes such as the delamination and fibers fracture can be observed. The bending fatigue test was performed under a constant load amplitude sinusoidal waveform. All rebars were subjected to fatigue tests under the R = 0.1 condition. As a result, the S-N curve was obtained, and basic fatigue characteristics were determined. The fatigue mechanism of bar failure under bending was further analyzed using SEM microscopy. It is worth noting that the failure and fracture mechanism plays a crucial role as a material quality indicator in the manufacturing process. The main mechanism of failure under static and cyclic loading during the bending test is widely discussed in this paper. The results obtained from fatigue tests encourage further analysis. The diametral compression test reflects the weakest nature of the composite materials based on the interlaminar compressive strength. The proposed methodology allows us to invariantly describe the experimental transversal strength of the composite materials. Considering the expected durability of the structure, the failure mechanism is likely to significantly improve their fatigue behavior under the influence of cyclic bending. The reasonable direction of searching for reinforcements of composite structures should be the improvement of the bearing capacity of the outer layers. In comparison with steel rebars (fatigue tensile test), the obtained results for GFRP are comparable in the HCF regime. It is worth noting that in the near fatigue endurance regime (2–5 × 106 cycles) both rebars exhibit similar behavior. Full article
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17 pages, 5622 KiB  
Article
Influence of Fine Grains on the Bending Fatigue Behavior of Two Implant Titanium Alloys
by Xiaojian Cao, Jiangpei Zhu, Fei Gao and Zhu Gao
Materials 2021, 14(1), 171; https://0-doi-org.brum.beds.ac.uk/10.3390/ma14010171 - 31 Dec 2020
Cited by 3 | Viewed by 1974
Abstract
By means of the ultrasonic surface impact (amplitude of 30 μm, strike number of 48,000 times/mm2), nanograins have been achieved in the surfaces of both Ti6Al4V(TC4) and Ti3Zr2Sn3Mo25Nb(TLM) titanium alloys, mainly because of the dislocation motion. Many mechanical properties are improved, [...] Read more.
By means of the ultrasonic surface impact (amplitude of 30 μm, strike number of 48,000 times/mm2), nanograins have been achieved in the surfaces of both Ti6Al4V(TC4) and Ti3Zr2Sn3Mo25Nb(TLM) titanium alloys, mainly because of the dislocation motion. Many mechanical properties are improved, such as hardness, residual stress, and roughness. The rotating–bending fatigue limits of TC4 and TLM subjected to ultrasonic impact are improved by 13.1% and 23.7%, separately. Because of the bending fatigue behavior, which is sensitive to the surface condition, cracks usually initiate from the surface defects under high stress amplitude. By means of an ultrasonic impact tip with the size of 8 mm, most of the inner cracks present at the zone with a depth range of 100~250 μm in the high life region. The inner crack core to TC4 usually appears as a deformed long and narrow α-phase, while the cracks in TLM specimens prefer to initiate at the triple grain boundary junctions. This zone crosses the grain refined layer and the deformed coarse grain layer. With the gradient change of elastic parameters, the model shows an increase of normal stress at this zone. Combined with the loss of plasticity and toughness, it is easy to understand these fatigue behaviors. Full article
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20 pages, 7685 KiB  
Article
The Evolution of Residual Stress in Rib-Diaphragm Joints of Orthotropic Steel Decks Subjected to Thermal Cutting and Welding
by Yongming Xiong, Chuanxi Li, Zhuoyi Chen, Jun He and Haohui Xin
Materials 2020, 13(17), 3804; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13173804 - 28 Aug 2020
Cited by 6 | Viewed by 2185
Abstract
Residual stresses change the stress ratio of fluctuating stresses, hence seriously affect the fatigue life of orthotropic steel decks (OSDs) under traffic loading. Residual stress distributions near the U rib-diaphragm joints are very complicated and need to be investigated further. In this paper, [...] Read more.
Residual stresses change the stress ratio of fluctuating stresses, hence seriously affect the fatigue life of orthotropic steel decks (OSDs) under traffic loading. Residual stress distributions near the U rib-diaphragm joints are very complicated and need to be investigated further. In this paper, a systematic method has been proposed for calculating the residual stress field in the joint of U rib and diaphragm due to thermal cutting and welding. Firstly, a mathematical model of cutting heat sources was established to predict the temperature field. Then, a numerical elastoplastic thermomechanical model was built to predict the residual stress evolutions in a diaphragm-rib joint through the whole fabrication process involving flame cutting and welding. Moreover, the simulated temperature contours at the fusion zone and the residual stress distributions in the rib-diaphragm joint were compared and verified against the experimental ones. The numerical results showed a great agreement with the experimental ones, indicating that the heat source model can be used to accurately predict the temperature field during flame cutting. Finally, the validated numerical model was utilized to conduct parametrical analyses on the effects of thermal processing rates, e.g., the cutting and welding speeds and on the residual stress distribution in the rib-diaphragm joint. The results indicate that a faster cutting speed and a slower welding speed can decrease the residual stress magnitude at the rib-diaphragm joints and reduce the high-stress zone near the diaphragm cutouts. Full article
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14 pages, 5230 KiB  
Article
Failure Analysis of a Flare Tip Used in Offshore Production Platform in Qatar
by Elsadig Mahdi and Ali Esmaeili
Materials 2020, 13(15), 3426; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13153426 - 03 Aug 2020
Cited by 1 | Viewed by 6604
Abstract
An immature failure of a gas flare tip used in Qatar oil and gas offshore industry was investigated throughout this study. The design lifetime of the flare was fifteen years; however, it manifested immature failure resulting in a reduction of its lifetime to [...] Read more.
An immature failure of a gas flare tip used in Qatar oil and gas offshore industry was investigated throughout this study. The design lifetime of the flare was fifteen years; however, it manifested immature failure resulting in a reduction of its lifetime to ten years. The flare is composed of different parts where the upper flare body and wind deflector showed failure while other components were still healthy. The material used for the aforementioned failed parts was Incoloy 800H, which is a highly corrosion and high-temperature resistant steel alloy. The material was rolled up and welded together with different welding joints. The root cause of failure was identified by using chemical analysis and microstructural and mechanical characterizations. For the mechanical characterization, an optical microscope (OM) and scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS) analyses were used for the specimen extracted from the failed part in order to ensure that the material mentioned by the manufacturer demonstrated the same metallurgical properties. For the mechanical characterization, two sets of specimens were used, one close to the failure region and the other far from the failure area. The chemical analysis revealed that the material was truthfully Incoloy 800H. The mechanical examination results showed a significant reduction of mechanical properties, i.e., the ultimate tensile strength (UTS) and microhardness dropped by 44% and 41% for samples close and far from the failure regions, respectively. Careful examination of the failed parts indicated that failure mostly took place in the vicinity of the welds, in particular near the joints. Improper joint designs, as well as a number of joints being designed in tiny areas, worsened the harmful effect of the heat-affected zone (HAZ), resulting in crack nucleation in the HAZ regions. The effect of welding in a combination of harsh service conditions of flare caused further crack extension where they merged, resulting in final immature failure. Full article
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22 pages, 8065 KiB  
Article
Decomposed Collaborative Modeling Approach for Probabilistic Fatigue Life Evaluation of Turbine Rotor
by Ying Huang, Guang-Chen Bai, Lu-Kai Song and Bo-Wei Wang
Materials 2020, 13(14), 3239; https://0-doi-org.brum.beds.ac.uk/10.3390/ma13143239 - 21 Jul 2020
Cited by 16 | Viewed by 2024
Abstract
To improve simulation accuracy and efficiency of probabilistic fatigue life evaluation for turbine rotor, a decomposed collaborative modeling approach is presented. In this approach, the intelligent Kriging modeling (IKM) is firstly proposed by combining the Kriging model (KM) and an intelligent algorithm (named [...] Read more.
To improve simulation accuracy and efficiency of probabilistic fatigue life evaluation for turbine rotor, a decomposed collaborative modeling approach is presented. In this approach, the intelligent Kriging modeling (IKM) is firstly proposed by combining the Kriging model (KM) and an intelligent algorithm (named as dynamic multi-island genetic algorithm), to tackle the multi-modality issues for obtaining optimal Kriging parameters. Then, the decomposed collaborative IKM (DCIKM) comes up by fusing the IKM into decomposed collaborative (DC) strategy, to address the high-nonlinearity problems for accelerating simulation efficiency. Moreover, the DCIKM-based probabilistic fatigue life evaluation theory is introduced. The probabilistic fatigue life evaluation of turbine rotor is regarded as case study to verify the presented approach; the evaluation results reveal that the probabilistic fatigue life of turbine rotor is 3296 cycles. The plastic strain range ∆εp and fatigue strength coefficient σf′ are the main affecting factors to fatigue life, whose effect probability are 28% and 22%, respectively. By comparing with direct Monte Carlo method, KM method, IKM method and DC response surface method, the presented DCIKM is validated to hold high efficiency and accuracy in probabilistic fatigue life evaluation. Full article
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