Wei-Lung Mao^1,*, Yu-Ying Chiu¹, Chao-Ting Chu², Bing-Hong Lin¹, Jian-Jie Hung³

Intelligent Automation & Soft Computing, Vol.32, No.2, pp. 923-936, 2022, DOI:10.32604/iasc.2022.019555

Abstract Electromagnets are commonly used as support for machine components and parts in magnetic bearing systems (MBSs). Compared with conventional mechanical bearings, the magnetic bearings have less noise, friction, and vibration, but the magnetic force has a highly nonlinear relationship with the control current and the air gap. This research presents a dynamic sliding mode backstepping control (DSMBC) designed to track the height position of modeless vertical MBS. Because MBS is nonlinear with model uncertainty, the design of estimator should be able to solve the lumped uncertainty. The proposed DSMBC controller can not only stabilize the nonlinear system under mismatched uncertainties,… More >

Junyu Chen¹, Yunwen Feng^1,*, Cheng Lu^1,2, Chengwei Fei²

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.2, pp. 1013-1027, 2021, DOI:10.32604/cmes.2021.016980

Abstract As the key component in aeroengine rotor systems, the health status of rolling bearings directly influences the reliability and safety of aeroengine rotor systems. In order to monitor rolling bearing conditions, a fusion fault diagnosis method, namely empirical mode decomposition (EMD)-Mahalanobis distance (E2MD) and improved wavelet threshold (IWT) (E2MD-IWT) for vibrational signals and acoustic emission (AE) signals is developed to improve the diagnostic accuracy of rolling bearings. The IWT method is proposed with a hard wavelet threshold and a soft wavelet threshold. Moreover, it is shown to be effective through numerical simulation. EMD is utilized to process the original AE… More >

Mahmoud Fakih^1,*, Jaafar Hallal¹, Hassan Darwich², Hala Damerji³

Structural Durability & Health Monitoring, Vol.15, No.3, pp. 247-260, 2021, DOI:10.32604/sdhm.2021.015174

Abstract Seismic earthquakes are a real danger for the construction evolution of high rise buildings. The rate of earthquakes around the world is noteworthy in a wide range of construction areas. In this study, we present the dynamic behavior of a high-rise RC building with dynamic isolators (lead-rubber-bearing), in comparison with a traditional shear wall system of the same building. Seismic isolation has been introduced in building construction to increase the structural stability and to protect the non-structural components against the damaging effects of an earthquake. In order to clarify the influence of incorporating lead rubber bearing isolators in the seismic… More >

Xiangxi Du^*, Yanhua Sun

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 917-929, 2021, DOI:10.32604/fdmp.2021.015710

Abstract A new type of foil bearings with a specific surface microstructure is studied. First, relevant boundary conditions based on the assumption of rarefied gas flow are proposed, then, the static bearing capacity and friction torque are analyzed in the framework of a numerical technique based on the discretization of the governing equation for rarefied gas-dynamics. It is shown that under the same static load, the difference between the minimum film thickness calculated in this exploration and the results provided by dedicated tests is not obvious; with an increase in the load, the simulation results are closer to the test values;… More >

Dileep Kumar^1,*, Imtiaz Hussain Kalwar², Tanweer Hussain¹, Bhawani Shankar Chowdhry¹, Sanaullah Mehran Ujjan¹, Tayab Din Memon³

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 393-408, 2021, DOI:10.32604/cmc.2021.014941

Abstract Reliability of rotating machines is highly dependent on the smooth rolling of bearings. Thus, it is very essential for reliable operation of rotating machines to monitor the working condition of bearings using suitable fault diagnosis and condition monitoring approach. In the recent past, Deep Learning (DL) has become applicable in condition monitoring of rotating machines owing to its performance. This paper proposes a novel bearing fault diagnosis method based on the processing and analysis of the vibration images. The proposed method is the UNET model that is a recent development in DL models. The model is applied to the 2D… More >

Bo Liu^1,*, Haoran Li¹, Shuya Liu²

Structural Durability & Health Monitoring, Vol.14, No.3, pp. 249-264, 2020, DOI:10.32604/sdhm.2020.06482

Abstract The buoyancy of groundwater can reduce the foundation bearing capacity and cause the metro tunnels to float as a whole, which threatens the safety of structures seriously. Therefore, uplift piles are set up to improve the structural stability. In this paper, FLAC3D software is used to establish the calculation models of pile foundation. The bearing failure process of uplift piles was simulated to study the influencing factors on single pile load bearing capacity as well as the cooperative work laws of pile groups. The load-displacement curves of pile top under different length-diameter ratios, pile-soil interface characteristics and pile types are… More >

Yan Liu¹, Yanfei Guo¹, Xufeng Sun^1,*, Meng Gong²

Journal of Renewable Materials, Vol.8, No.9, pp. 1111-1127, 2020, DOI:10.32604/jrm.2020.09575

Abstract Poplar Laminated Veneer Lumber (Poplar LVL) is a new type of engineering materials with high strength, good reliability and small variability. Poplar LVL is manufactured from the fast-growing poplar, which is widely used in packaging, furniture and others, however, is rarely adopted in construction. In order to explore the feasibility of poplar LVL trusses in construction of roof, four 4.5-m-span Fink-and-Howe trusses were designed and assembled, which were made of poplar LVL with bolted- and tooth-plated connections. Vertical static loading on the upper chord joints of a truss was imposed by self-balancing test device. The mechanical properties of trusses were… More >

Xiaoping Zhao^{1, 4}, Yifei Wang^{2, *}, Yonghong Zhang², Jiaxin Wu¹, Yunqing Shi³

CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 571-587, 2020, DOI:10.32604/cmc.2020.06363

Abstract Stochastic resonance can use noise to enhance weak signals, effectively reducing the effect of noise signals on feature extraction. In order to improve the early fault recognition rate of rolling bearings, and to overcome the shortcomings of lack of interaction in the selection of SR (Stochastic Resonance) method parameters and the lack of validation of the extracted features, an adaptive genetic random resonance early fault diagnosis method for rolling bearings was proposed. compared with the existing methods, the AGSR (Adaptive Genetic Stochastic Resonance) method uses genetic algorithms to optimize the system parameters, and further optimizes the parameters while considering the… More >

Fengrui Liu^{1, 2, 3}, Wanting Yao^{1, 2}, Xinhong Shi^{4, *}, Libin Zhao^{1, 2}, Jianyu Zhang^{5, *}

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 977-999, 2020, DOI:10.32604/cmc.2020.07184

Abstract To minimize the mass and increase the bearing failure load of composite doublelap bolted joints, a three-step optimization strategy including feasible region reduction, optimization model decoupling and optimization was presented. In feasible region reduction, the dimensions of the feasible design region were reduced by selecting dominant design variables from numerous multilevel parameters by sensitivity analyses, and the feasible regions of variables were reduced by influence mechanism analyses. In model decoupling, the optimization model with a large number of variables was divided into various sub-models with fewer variables by variance analysis. In the third step, the optimization sub-models were solved one… More >

P. CORNEJO*, E.L. CAMADRO**, R.W. MASUELLI*

BIOCELL, Vol.30, No.3, pp. 413-421, 2006, DOI:10.32604/biocell.2006.30.413

Abstract The Endosperm Balance Number (EBN) is an important concept for potato breeding and has evolutionary importance in tuber-bearing Solanum species. The EBN is part of the post-zygotic hybridization barriers in the group and represents a reproductive isolating mechanism. Few genes have been proposed to be involved in its genetic control; until now, however, neither specific genes nor its molecular basis have been well established. Histological observations of embryo and endosperm development in inter-EBN crosses in tuber-bearing Solanum revealed phenotypes similar to those recently described in Arabidopsis seed mutants. The common feature between them is that the endosperm nuclei become greatly… More >