Article
Engineering, Multidisciplinary
Takashi Honda, Takuya Fukahori, Takumi Tokiyoshi, Yasuharu Chuman, Toshihide Igari, Alan C. F. Cocks
Summary: This paper discusses the prediction of residual life for Type IV creep failure in Ultra Super Critical (USC) plants by considering the increase of creep void density and the influence of stress state in welded joints with non-uniform weld metal materials, heat affected zone (HAZ) and base metal, compared to experimental results at 650 degrees C.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Materials Science, Multidisciplinary
Stuart Holdsworth
Summary: This study focuses on the examination of high-temperature damage in Ni-alloy/steel dissimilar metal welds and its impact on creep-rupture times and creep-fatigue endurances. The research emphasizes the importance of systematic and detailed post-test examination of the damage in x-weld microstructures, and characterizes available evidence for Alloy-617/1%Cr-steel welds at 550 degrees C and Alloy-617/10%Cr-steel welds at 575 degrees C. The study also determines CR and CF weld strength factors for the two DMWs based on the respective kinetics of microstructural developments adjacent to the fusion line and in the FG/ICHAZ of the steel.
MATERIALS AT HIGH TEMPERATURES
(2021)
Review
Engineering, Mechanical
Mohsin Sattar, A. R. Othman, S. Kamaruddin, Maaz Akhtar, Rashid Khan
Summary: This study presents a review of five established models for creep prediction, analyzing their significance and limitations. It explains creep phenomenon and mechanism, and provides a historical overview of the models. Through case studies, the pros and cons of using the models are highlighted, and comparisons are made among them. This review paper serves as a reliable reference for the selection of creep prediction models.
ENGINEERING FAILURE ANALYSIS
(2022)
Review
Materials Science, Multidisciplinary
Kun Zhang, Jian-Ping Tan, Wei Sun, Kamran Nikbin, Shan -Tung Tu
Summary: This article discusses the failure behavior and life prediction of engineering materials under multiaxial loading. A multiaxial stress rupture criterion (MSRC) is proposed to distinguish different failure modes, and a multiaxial factor alpha is developed to quantify the multiaxial response of material/geometry combinations. Different methods for determining MSRC are evaluated, and the use of continuum damage mechanics approaches in determining MSRC is recommended, considering the influence of creep failure mechanisms. The correlation between uniaxial material parameters and alpha is also analyzed. The study finds that the increase of uniaxial creep ductility parameter lambda is accompanied by a decrease in alpha, indicating the role of creep ductility in the multiaxial rupture behavior of materials.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Multidisciplinary
Yang Guo, Chunrong Ma, Xiaowu Luo, Yan Chen, Yanyan Huang, Yucun Zhan, Xia Li, Qinghua Zhou, Jianxun Zhang, Jiankun Xiong, Jianping Yang, Guijun Mao, Lin Yang, Fuheng Nie
Summary: The research focuses on the creep behavior and fracture characteristics of welded joints of heat-resistant steel 12Cr10Co3W2MoNIVNbNB under different creep conditions. Ductile rupture in the parent material and intergranular type IV failure in the heat-affected zone were observed. The industry requirements for extrapolating creep rupture stresses for 100,000 hours were met. The influence of mediate stress range on creep life was found to be greater compared to high or low stresses. The growth of creep cavities and formation of cracks were analyzed, with precipitates serving as preferential cavity nucleation sites. Nanoindentation results showed no decreasing trend in local physical-mechanical properties with increasing creep time.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2023)
Article
Engineering, Mechanical
Dongxu Zhang, Menghui Lv, Zhixun Wen
Summary: A unified creep rupture life prediction method based on continuum damage mechanics under multiaxial stress was proposed in this paper. By optimizing the traditional skeletal point stress method, the number of models that need to be computed during the simulation was reduced by 5/6, and the generality of the method for different notch sizes was significantly improved. Creep tests on Ni-based superalloy round bar specimens with different notch sizes were conducted to verify the accuracy of the method. Furthermore, creep rupture mechanism analyses were conducted for different notch sizes by combining finite element simulations with experiments, stress and damage were analyzed, and void growth was explained based on triaxial stress states.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Nanoscience & Nanotechnology
Yu Zhang, Zhipeng Cai, Chaoyu Han, Xin Huo, Manjie Fan, Kejian Li, Jiluan Pan
Summary: This study elucidated the influence of macrosegregation on interface structure and the effect of this influence on creep failure during post weld heat treatment in dissimilar metal welds.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Xiaogang Li, Junfeng Nie, Xin Wang, Kejian Li, Zhipeng Cai, Haiquan Zhang
Summary: This study investigates the behaviour and mechanism of interfacial microstructure evolution during long term high temperature exposure and the effect of interface structure on creep failure in dissimilar metal welds. The results show that the welding of nickel-based and ferritic materials leads to the formation of an interfacial martensite layer in the ferritic steel side of the weld. During long term high temperature exposure, the interfacial martensite transforms to ferrite due to carbon diffusion and migration near the interface between the martensite layer and the weld metal. Under creep conditions, the failure of the welds is prone to occur along the interface between the weld metal and the ferritic steel, which is related to strain concentration around the interfacial ferrite formed during service.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Geological
Fernando E. Garcia, Jonathan D. Bray
Summary: The influence of soil inhomogeneity on earthquake surface fault rupture was analyzed using DEM, revealing that soil layers with contrasting densities can affect the path of fault rupture propagation. In some cases, the presence of a thin layer can significantly alter the path of fault rupture propagation. The simulation results highlight the ability of DEM to capture the response of granular materials in scenarios that are difficult to achieve physically in the laboratory.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Bofeng Li, Jundong Wang, Yao Yao
Summary: In this study, creep experiments were conducted on sintered nano-silver specimens to investigate its creep behavior at different temperatures. It was found that increasing the temperature led to significant softening and accelerated decay of creep rate. The high temperature sensitivity of sintered nano-silver creep was attributed to void formation. A new theoretical model based on the theory of entropy increment was developed to accurately predict the creep strain of sintered nano-silver.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Materials Science, Composites
Fillip Cortat Alves, Francisco Maciel Monticeli, Roberta Motta Neves, Herman Jacobus Cornelis Voorwald, Maria Odila Hilario Cioffi, Heitor Luiz Ornaghi
Summary: This study evaluated the dynamic mechanical properties and creep behavior of glass/epoxy composites with different void contents by using X-ray microtomography. The void content was found to interfere with stress transferring, leading to lower storage modulus and higher creep deformation, especially in the glass transition region. Temperature and stress levels also played a role in affecting the creep behavior of the composites, along with void content and morphology.
COMPOSITES COMMUNICATIONS
(2021)
Article
Construction & Building Technology
Da Liu, Jianglin Gao, Fang Chen, Songtao Hu, Xiaohua Zhao, Yan Li
Summary: The study investigates the stability issues of the red-bed soft rock channel bank slope using indoor tests and numerical models, finding that the slope stability safety factors under different conditions are all greater than the recommended values in the specification.
ADVANCES IN CIVIL ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
K. Naresh, K. A. Khan, W. J. Cantwell, R. Umer
Summary: This study investigates the compaction-creep response of a glass/epoxy prepreg system under different temperatures, pressures, and compaction speeds. The results show that increasing the compaction speed leads to increased total strain, percentage of compaction creep, and resulting permanent deformation. The percentage of compaction-creep increases with temperature up to 55 degrees C and then decreases. Additionally, a decrease in creep deformation is observed at higher temperatures due to resin squeezing out. The void content in the post-creep laminates is determined using an analytical model and compared with XCT-developed geometrical models, with good agreement between the two methods.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Xue Wang, Xiao Wang, Ya-Lin Zhang, Chuang Wang, You Li, Qiao-Sheng Huang
Summary: This study investigated the microstructure and creep fracture characteristics of the HR3C/T92 dissimilar steel welded joint using Ni-based filler metal. It was found that the type IV cracking occurred preferentially at the FGHAZ of the T92 side, triggered by the accumulation of cavity damage, leading to brittle fracture. The presence of blocky delta-ferrite phases in the CGHAZ of T92 side did not make it the weakest zone for the early failure of the welded joint compared to the FGHAZ.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Chemistry, Physical
Mohsin Sattar, Abdul Rahim Othman, Maaz Akhtar, Shahrul Kamaruddin, Rashid Khan, Faisal Masood, Mohammad Azad Alam, Mohammad Azeem, Sumiya Mohsin
Summary: The Kachanov-Rabotnov isotropic creep damage constitutive model has been used to evaluate high-temperature component creep deformation in various scenarios. A curve-fitting technique was proposed to extrapolate creep behavior beyond available data points by fitting the Kachanov-Rabotnov model to limited creep data. The method is useful for predicting material creep behavior and generating creep curves, as demonstrated in the study on SS-316 through experimental validation and sensitivity analysis.
Article
Engineering, Mechanical
Willy Ank de Morais, Railson Bolsoni Falcao, Mario Boccalini Jr, Fernando Jose Gomes Landgraf
Summary: This study compares the fatigue behavior of bcc Nb-48 wt%Ti (Ti-36at%Nb) alloy parts processed by Laser Powder Bed Fusion (L-PBF) using two different types of powders (spherical powder produced by Plasma Atomization and irregularly shaped powder produced by Hydride-Dehydride). The results show that the fatigue behavior is similar for both powders, but the specimens produced from the Hydride-Dehydride powder have higher dispersed results. Fracture primarily occurs in the porosities near the machined sample surface, and the fatigue cracks propagate in a zigzag mode parallel to the L-PBF building direction.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Guoxi Jing, Shuai Sun, Teng Ma, Shubo Li, Tian Ma, Junchao Wei, Jianchao Pang
Summary: This study proposes a parameter identification method for predicting the TMF life of CGI materials used in cylinder heads. The study evaluates the TMF behavior of RuT450 material and successfully predicts its TMF life using multi-objective optimization. The results highlight the influence of plastic strain amplitude, temperature, and strain rate on the damage mechanism and life prediction.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xin Zhang, Xu Li, Weipeng Xu, Kuidong Gao, Kao Jiang, Xinyu Wang, Hongxin Wei
Summary: Conical picks are commonly used in tunnel excavation and often experience high temperatures during the cutting process. This study investigated the influence of temperature on the wear of conical picks and proposed a method for measuring rock abrasiveness that takes into account the thermal effect. The experimental results showed that cooling liquid reduced the maximum temperature and the mean mass loss of the conical pick. Additionally, the study examined the characteristics of oxygen and found evidence of peeling, cracking, and oxidation on the grinding rod used for rock abrasiveness measurement.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Vivek Srivastava, Deependra Singh, A. G. Rao, V. P. Deshmukh
Summary: Engine gear failures are a significant concern in various industries. Investigating each gear failure and determining the root cause is important for preventing future failures. This study used experimental and numerical analysis techniques to investigate the premature failure of a flywheel gear in a marine diesel engine. The findings revealed that the gear failed due to overload stresses caused by overload torque generated from sudden inertial thrust in the internal combustionengine.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Jun Zhang, Weidong Liu, Feilong Liu, Zhiqiang Yang, Jinfang Peng, Minhao Zhu
Summary: During a major overhaul of an aeroengine, a cracked stator vane of the low-pressure compressor was discovered, with the crack originating from a corrosion pit located on the arc transition between the leading edge and the upper edge plate. The fracture surface exhibited signs of fatigue cracks, indicating a pit-related fatigue crack. Metallographic examination revealed that most corrosion pits were distributed beneath the bulging or peeling paint layer on the leading edge and the concave side. Identification of the corrosion products showed the presence of sulfate and alumina, suggesting atmospheric corrosion as a likely cause for the cracked stator vane.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Juan Jose Jimenez de Cisneros Fonfria, Ester Olmeda, Susana Sanz, Maria Garrosa, Vicente Diaz
Summary: Energy absorbing devices in vehicles can partially transform impact energy and protect passengers. In this paper, the failure analysis of the underframe crumple zone in a train car was conducted through finite element simulations, showing that the component acted properly after the impact.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Fengqi Zhang, Gang Luo, Haiyang Zhang, Peihong Cong, Lulu Liu, Wei Chen
Summary: In this study, a predictive model for bird strike trajectory was developed based on the quasi-linear viscoelastic model. By combining simulation analysis under multiple conditions, the model reproduced the trajectory change law in low and medium speed bird impact experiments.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
S. M. de Gouveia, L. de Abreu Correa, D. B. Teles, M. Oliveira, T. G. R. Clarke
Summary: Emergency Shutdown Valves (EDSVs) are used in industrial applications to interrupt fluid flow during hazardous events. The damage to the valve seats can be detected by analyzing the pressure and torque data. This study compared three processing options and found that evaluating the complete signature with a Gradient Boosting Classifier algorithm is the most effective strategy.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xinyan Jin, Kai Wang, Hongwei Qian
Summary: This study investigated the root cause of an abnormal premature groove-clogging failure on a sink roll in a hot-dip galvanizing line. It was found that the failure was caused by the buildup of a large amount of Fe2Al5Znx dross in the grooves, and the key factor was the control of Tstrip.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Zhiqiang Li, Jie Li, Cen Li, Xiaodong Xie, Zhiyong Yang
Summary: In this study, the microstructure evolution of the material in the hot spot area of the high-speed train brake disc was observed and the mechanism of mechanical property degradation was obtained through tensile tests. The research results provide guidance for crack damage identification of the brake disc and condition-based maintenance.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Lijia Luo, Yincheng Wang, Wei Chen, Zuming Zhao, Wenfei Chen, Shiyi Bao
Summary: Tube-to-tube impact wear is a significant factor in the failure of alloy 690 tubes in nuclear steam generators. This paper investigates the wear damage mechanism and detection method of alloy 690 tubes under tube-to-tube impact loads. The results reveal the wear damage mechanism through analysis of macro and micro morphologies as well as metallographic structures. A nonlinear ultrasonic wave mixing method is proposed for damage detection and a detection device is developed to implement this method. Experimental results indicate that the damage mode of tube-to-tube impact wear varies with impact load and cycle number, and the nonlinear modulation index is effective in assessing the damage degree of alloy 690 tubes.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xing-Ju Yang, Feng Lin, Xu Du, Lu Qiu
Summary: This paper proposes a novel method of improving the progressive collapse resistance of RC frame structures by adding locally debonded kinked steel plates (KPs). Experimental tests and finite element analysis reveal that the addition of KPs significantly enhances the ultimate resistance and deformability of the beam-slab substructures. The mechanism of resistance improvement is explained, and an analytical model is developed for predicting the ultimate resistance of the structures.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xiaohe Wang, Zengqiang Cao
Summary: This paper presents a dynamic installation (DI) method based on electromagnetic force to reduce damage to composite laminates and improve joint performance. The study shows that DI can effectively decrease installation resistance, reduce severe damage to laminates, and improve stress distribution in the joint.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Jitong Cui, Yingying Kong, Cuiwei Liu, Baoping Cai, Faisal Khan, Yuxing Li
Summary: This paper presents a method for quantifying the failure probability of hydrogen doped pipelines and utilizes Bayesian network for quantitative calculation. The results show that this method can more accurately assess the failure probability of hydrogen doped pipelines and provide a decision basis for preventing failure accidents.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Yiping Jiang, Maoru Chi, Jungang Yang, Liangcheng Dai, Yuchen Xie, Zhaotuan Guo
Summary: This article investigates and simulates the derailment of empty freight trains at the switch section of a turnout in the diverging route, and proposes preventive measures. The results show that the derailment is caused by the combined effect of various factors, and reducing the longitudinal coupler force and the wheel rail friction coefficient can decrease the possibility of derailment. Additionally, installing a guard rail in front of the turnout can effectively prevent derailment.
ENGINEERING FAILURE ANALYSIS
(2024)
