Guanhua Wang¹, Jinghua Wang¹, Xuemei Huang^1,*, Leian Zhang¹, Weisheng Liu²

Energy Engineering, Vol.119, No.4, pp. 1649-1662, 2022, DOI:10.32604/ee.2022.019695

Abstract A new dual-actuator fatigue loading system of wind turbine blades was designed. Compared with the traditional pendulum loading mode, the masses in this system only moved linearly along the loading direction to increase the exciting force. However, the two actuators and the blade constituted a complicated non-linear energy transferring system, which led to the non-synchronization of actuators. On-site test results showed that the virtual spindle synchronous strategy commonly used in synchronous control was undesirable and caused the instability of the blade’s amplitude eventually. A cross-coupled control strategy based on the active disturbance rejection algorithm was proposed. Firstly, a control system… More >

Anita Gehlot¹, Rajesh Singh¹, Sweety Siwach², Shaik Vaseem Akram¹, Khalid Alsubhi³, Aman Singh^4,*, Irene Delgado Noya^4,5, Sushabhan Choudhury²

CMC-Computers, Materials & Continua, Vol.72, No.1, pp. 999-1015, 2022, DOI:10.32604/cmc.2022.023861

Abstract Wearable monitoring devices are in demand in recent times for monitoring daily activities including exercise. Moreover, it is widely utilizing for preventing injuries of athletes during a practice session and in few cases, it leads to muscle fatigue. At present, emerging technology like the internet of things (IoT) and sensors is empowering to monitor and visualize the physical data from any remote location through internet connectivity. In this study, an IoT-enabled wearable device is proposing for monitoring and identifying the muscle fatigue condition using a surface electromyogram (sEMG) sensor. Normally, the EMG signal is utilized to display muscle activity. Arduino… More >

Gaozheng Zhao¹, Changchao Liu¹, Lingyu Sun¹, Ning Yang², Lei Zhang¹, Mingshun Jiang¹, Lei Jia¹, Qingmei Sui^1,*

Structural Durability & Health Monitoring, Vol.16, No.1, pp. 81-96, 2022, DOI:10.32604/sdhm.2022.016905

Abstract Fatigue crack prediction is a critical aspect of prognostics and health management research. The particle filter algorithm based on Lamb wave is a potential tool to solve the nonlinear and non-Gaussian problems on fatigue growth, and it is widely used to predict the state of fatigue crack. This paper proposes a method of lamb wave-based early fatigue microcrack prediction with the aid of particle filters. With this method, which the changes in signal characteristics under different fatigue crack lengths are analyzed, and the state- and observation-equations of crack extension are established. Furthermore, an experiment is conducted to verify the feasibility… More >

Seyyed Mohammad Javad Golhosseini¹, Mohsen Aliabadi^2,*, Rostam Golmohammadi³, Maryam Farhadian⁴, Mehdi Akbari⁵, Morteza Hamidi Nahrani⁶, Mehdi Samavati⁷

Sound & Vibration, Vol.56, No.1, pp. 37-49, 2022, DOI:10.32604/sv.2022.014616

Abstract There is little information about drivers’ body balance responses to combined exposure of noise and vibration. To fill the gap, this study aims to investigate the combined effects of exposure to noise and whole-body vibration (WBV) on the body balance under simulated driving conditions. For this purpose, 30 male participants were exposed to noise level at 85 dB(A) and two vibration levels (0.87 and 1.3 m/s²) in five sessions. The design of the study was repeated-measures, and it attempted to assess the effects of 40 minutes of exposure to noise and/or WBV. Moreover, the participants’ fatigue was measured with the… More >

Md Zahirul Islam, Chad A. Ulven^*

Journal of Renewable Materials, Vol.10, No.5, pp. 1185-1200, 2022, DOI:10.32604/jrm.2022.018018

Abstract Among natural fibers, flax fiber reinforced polymer matrix composites show excellent dynamic/fatigue properties due to its excellent damping properties. Knowledge about fatigue limit and effect of loading frequency on fatigue limit is very crucial to know before being used a member as a structural component. Fatigue limit of fiber reinforced composite is measured through high cycle fatigue strength (HCFS). The effect of loading frequency on the HCFS of flax fiber reinforced polymer matrix composites was investigated using stabilized specimen surface temperature based thermographic and dissipated energy per cycle-based approaches. Specimens of unidirectional flax fiber reinforced thermoset composites were tested under… More >

Yonghua Li^1,*, Xiaoning Bai², Shanshan Shi¹, Shenxuan Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 1077-1092, 2022, DOI:10.32604/cmes.2022.018181

Abstract Multiple failure modes and strength degradation are usually inherent in the gear transmission system, which brings new challenges for conducting fatigue reliability analysis and design. This paper proposes a novel dynamic fatigue reliability analysis method for failure dependence and strength degradation based on the combination of the Copula function and Gamma process. Firstly, the dynamic simulation model of the gear transmission system is established to obtain the dynamic stress-time history. The Gamma process is then used to describe the strength degradation to establish the dynamic stress-strength interference model. The marginal distribution functions of tooth contact fatigue and dedendum bending fatigue… More >

Borui Yang¹, Jun Luo², Bo Wan^1,*, Yutai Su^1,3, Guicui Fu¹, Xu Long^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 1113-1134, 2022, DOI:10.32604/cmes.2022.018037

Abstract A thermal fatigue lifetime prediction model of ceramic ball grid array (CBGA) packages is proposed based on the Darveaux model. A finite element model of the CBGA packages is established, and the Anand model is used to describe the viscoplasticity of the CBGA solder. The average viscoplastic strain energy density increment ΔWave of the CBGA packages is obtained using a finite element simulation, and the influence of different structural parameters on the ΔWave is analyzed. A simplified analytical model of the ΔWave is established using the simulation data. The thermal fatigue lifetime of CBGA packages is obtained from a thermal… More >

Yongxin Li¹, Guoyun Zhou¹, Tao Chang^1,*, Liming Yang², Fenghe Wu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 499-511, 2022, DOI:10.32604/cmes.2022.017630

Abstract Because of descriptive nonlinearity and computational inefficiency, topology optimization with fatigue life under aperiodic loads has developed slowly. A fatigue constraint topology optimization method based on bidirectional evolutionary structural optimization (BESO) under an aperiodic load is proposed in this paper. In view of the severe nonlinearity of fatigue damage with respect to design variables, effective stress cycles are extracted through transient dynamic analysis. Based on the Miner cumulative damage theory and life requirements, a fatigue constraint is first quantified and then transformed into a stress problem. Then, a normalized termination criterion is proposed by approximate maximum stress measured by global… More >

Xudong Wang^1,2, Changqing Miao^1,2,*, Mao Yang^1,2, Youliang Ding^1,2

Structural Durability & Health Monitoring, Vol.15, No.4, pp. 299-316, 2021, DOI:10.32604/sdhm.2021.017526

Abstract This study presents an investigation on the fatigue analysis of four types of details on orthotropic steel decks (OSDs) for a cable-stayed super-wide steel box girder bridge based on finite-element analysis (FEA) with vehicle transverse distribution model (VTDM). A high-fidelity 3D FE model verified by the static load test is established to satisfy the fatigue analysis accuracy. The stress behavior of super-wide steel box girders under the vehicle load at different lane locations is investigated. Then, considering the effect of VTDM, the fatigue life analysis of four typical details is performed using the Miner cumulative damage rule. The results show… More >

Jinghua Wang¹, Leian Zhang¹, Xuemei Huang^1,*, Jinfeng Zhang², Chengwei Yuan¹

Energy Engineering, Vol.119, No.1, pp. 407-418, 2022, DOI:10.32604/EE.2022.016439

Abstract Transverse crack often occurs in the trailing edge region of the blade when subjected to the excessive edgewise fatigue load. In this paper a refined model was established through local mesh refinement methods in order to investigate the initiation mechanism of crack and its extension in blade trailing edge. The material stress around the crack in trailing edge region under different thicknesses is calculated based on the fracture mechanics theory. The factors affecting the fatigue robustness of blade trailing edge are concluded by investigating the results of finite element analysis and coupons test. Compared with the laminate, the lower fatigue… More >