Xue-Qin Li¹, Lu-Kai Song^2,3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 665-684, 2024, DOI:10.32604/cmes.2024.048445

Abstract Fatigue reliability-based design optimization of aeroengine structures involves multiple repeated calculations of reliability degree and large-scale calls of implicit high-nonlinearity limit state function, leading to the traditional direct Monte Claro and surrogate methods prone to unacceptable computing efficiency and accuracy. In this case, by fusing the random subspace strategy and weight allocation technology into bagging ensemble theory, a random forest (RF) model is presented to enhance the computing efficiency of reliability degree; moreover, by embedding the RF model into multilevel optimization model, an efficient RF-assisted fatigue reliability-based design optimization framework is developed. Regarding the low-cycle fatigue reliability-based design optimization of… More >

Ying Wang^1,*, Longxiao Chao¹, Jun Chen², Songbai Jiang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 201-227, 2024, DOI:10.32604/cmes.2024.046129

Abstract In order to investigate the fatigue performance of orthotropic anisotropic steel bridge decks, this study realizes the simulation of the welding process through elastic-plastic finite element theory, thermal-structural sequential coupling, and the birth-death element method. The simulated welding residual stresses are introduced into the multiscale finite element model of the bridge as the initial stress. Furthermore, the study explores the impact of residual stress on crack propagation in the fatigue-vulnerable components of the corroded steel box girder. The results indicate that fatigue cracks at the weld toe of the top deck, the weld root of the top deck, and the… More > Graphic Abstract

Maria Inês Clara^1,2,3,*, Maria Cristina Canavarro^2,3, Ana Severina⁴, Susana Ramos⁴, Carla Rafael⁴, Ana Allen Gomes^1,2,3

Psycho-Oncologie, Vol.18, No.1, pp. 49-57, 2024, DOI:10.32604/po.2023.044320

Abstract Aims: We aimed to compare cancer survivors’ fatigue expression with that of the general population and examine psychobiological factors associated with fatigue. Procedure: In this quantitative, transversal study, we analyzed clinical and sociodemographic indicators of 389 participants (68.38% females): 148 cancer survivors on active treatment, 55 disease-free survivors, 75 patients with another chronic disease, and 111 healthy individuals. Results: Fatigue was expressed dissimilarly in patients with a previous history of cancer and participants without a history of cancer. Survivors on active treatment reported significantly higher levels of fatigue than the other clinical status groups. Nonetheless, some level of cancer-related fatigue… More >

Yujia Liu^1,2, Bo Xu¹, Sen Tang³, Lang Li¹, Chao He¹, Qingyuan Wang^1,2,3, Chong Wang^1,2,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.010057

Abstract This paper presents a thermodynamic characterization method for estimating the internal crack growth rate, which has been a puzzle in very high cycle fatigue research. A theoretical approach of surface temperature is established with crack size, initiation site, and time for thin sheet material. Infrared thermography is used to study the inner crack behavior and the heat dissipation phenomenon under 20 kHz vibration loading on high-strength stainless steel. A numerical simulation reveals the consequent temperature elevation on the surfaces by the heat generation at the crack tip and the heat conduction. Ultimately, the internal crack growth rate and final fatigue… More >

Gustavo von Zeska de França, Roberto Luís de Assumpção, Marco Antonio Luersen^*, Carlos Henrique da Silva

CMC-Computers, Materials & Continua, Vol.77, No.2, pp. 1411-1424, 2023, DOI:10.32604/cmc.2023.043811

Abstract Austempered ductile iron (ADI) is composed of an ausferritic matrix with graphite nodules and has a wide range of applications because of its high mechanical strength, fatigue resistance, and wear resistance compared to other cast irons. The amount and size of the nodules can be controlled by the chemical composition and austenitizing temperature. As the nodules have lower stiffness than the matrix and can act as stress concentrators, they influence crack propagation. However, the crack propagation mechanism in ADI is not yet fully understood. In this study, we describe a numerical investigation of crack propagation in ADIs subjected to cyclic… More >

Xiaojie Jiang¹, Xin Li¹, Yining Xu¹, Dong Sun¹, Julien S. Baker², Yaodong Gu^1,3,*

Molecular & Cellular Biomechanics, Vol.20, No.2, pp. 67-79, 2023, DOI:10.32604/mcb.2023.042910

Abstract

The aim of this study was to investigate whether kinematic data during a countermovement jump (CMJ) could explain the post-activation performance enhancement (PAPE) effects following acute resistance exercise. Twenty-four male participants with resistance training and jumping experience were recruited and randomly assigned to either the experimental group (PAPE-stimulus) (n = 12) or the control group (n = 12). In the experimental group, participants performed 5 reps of squats at 80% 1RM to induce PAPE, while the control group received no intervention. Both groups performed three CMJ tests before (PRE) and at immediate (POST0), 4 (POST4), 8 (POST8), and 12 (POST12)… More > Graphic Abstract

Wenzhe Guo¹, Leian Zhang^1,*, Chao Lv², Weisheng Liu³, Jiabin Tian²

Energy Engineering, Vol.120, No.10, pp. 2307-2323, 2023, DOI:10.32604/ee.2023.030029

Abstract Aiming at the drift problem that the tracking control of the actual load relative to the target load during the electromagnetic excitation biaxial fatigue test of wind turbine blades is easy to drift, a biaxial fatigue testing machine for electromagnetic excitation is designed, and the following strategy of the actual load and the target load is studied. A Fast Transversal Recursive Least Squares algorithm based on fuzzy logic (Fuzzy FTRLS) is proposed to develop a fatigue loading following dynamic strategy, which adjusts the forgetting factor in the algorithm through fuzzy logic to overcome the contradiction between convergence accuracy and convergence… More >

Shu Dai^1,*, Bert Sweetman²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09687

Abstract Short-term wind process is normally assumed to be a Gaussian distribution, such as TurbSim, the widely used 3D wind field tool. Nowadays, newest researches indicate that non-Gaussian wind model is believed to be more accurate according to the field observation data. A new numerical method is proposed to generate non-Gaussian wind filed using translation process theory and spectral representation method. This study presents a comprehensive investigation on power production and blades fatigue damage of floating offshore wind turbines (FOWTs) to the non-Gaussian wind field. The comparisons of Gaussian and non-Gaussian simulation results indicate that the non-Gaussian wind fields will cost… More >

Pandi Zhao¹, Zebang Zheng^1,*, Mei Zhan¹, Hongwei Li¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09508

Abstract Metallic sealing rings made from nickel-based superalloys are critical components of aero engines that prevent the leakage of high-pressure liquid or gas fuel. As one of the main failure modes, fatigue cracking has been a concern for the aerospace industries because the formation of even a micro-crack may cause an aviation accident. For the purpose of manufacturing fatigue-resisting sealing rings, much effort has been spent on the lifetime predicting under fatigue loadings. However, the fatigue analysis of metallic sealing rings is challenging due to several aspects. On the one hand, the diameter of the rings (>100mm) is orders of magnitude… More >

Zhengmao Yang^1,*, Junjie Yang², Yang Chen³, Fulei Jing⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09229

Abstract Woven ceramic matrix composites (CMCs), exhibiting excellent thermomechanical properties at high temperatures, are promising as alternative materials to the conventional nickel-based superalloys in the hot section components of aero-engines. Therefore, understanding and predicting the lifetime of CMCs is critical. Fatigue prediction of woven CMCs currently involves long-term and costly testing. A feasible alternative is to use predictive modelling based on a deep understanding of the damage mechanisms. Therefore, this study develops a multiscale analysis modelling method for predicting the fatigue life of CMC materials at high temperature by investigating the thermomechanical fatigue damage evolution. To represent the global thermomechanical properties… More >