Qifa Lang, Yuqiao Zheng^*, Tiancai Cui, Chenglong Shi, Heyu Zhang

Energy Engineering, Vol.121, No.2, pp. 483-498, 2024, DOI:10.32604/ee.2023.042437

Abstract This work presents a novel approach to achieve nonlinear vibration response based on the Hamilton principle. We chose the 5-MW reference wind turbine which was established by the National Renewable Energy Laboratory (NREL), to research the effects of the nonlinear flap-wise vibration characteristics. The turbine wheel is simplified by treating the blade of a wind turbine as an Euler-Bernoulli beam, and the nonlinear flap-wise vibration characteristics of the wind turbine blades are discussed based on the simplification first. Then, the blade’s large-deflection flap-wise vibration governing equation is established by considering the nonlinear term involving the centrifugal force. Lastly, it is… More >

R. Muthaiyan^1,*, Dr M. Malleswaran²

Computer Systems Science and Engineering, Vol.40, No.1, pp. 299-312, 2022, DOI:10.32604/csse.2022.018034

Abstract In this paper, an Automated Brain Image Analysis (ABIA) system that classifies the Magnetic Resonance Imaging (MRI) of human brain is presented. The classification of MRI images into normal or low grade or high grade plays a vital role for the early diagnosis. The Non-Subsampled Shearlet Transform (NSST) that captures more visual information than conventional wavelet transforms is employed for feature extraction. As the feature space of NSST is very high, a statistical t-test is applied to select the dominant directional sub-bands at each level of NSST decomposition based on sub-band energies. A combination of features that includes Gray Level… More >

Dimitra Papagianni^{1, 2}, Magd Abdel Wahab^{3, 4, *}

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 79-97, 2020, DOI:10.32604/cmc.2020.07988

Abstract This paper deals with modeling of the phenomenon of fretting fatigue in heterogeneous materials using the multi-scale computational homogenization technique and finite element analysis (FEA). The heterogeneous material for the specimens consists of a single hole model (25% void/cell, 16% void/cell and 10% void/cell) and a four-hole model (25% void/cell). Using a representative volume element (RVE), we try to produce the equivalent homogenized properties and work on a homogeneous specimen for the study of fretting fatigue. Next, the fretting fatigue contact problem is performed for 3 new cases of models that consist of a homogeneous and a heterogeneous part (single… More >

Y. W. Kwon¹, K. Roach¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.1, pp. 63-72, 2004, DOI:10.3970/cmes.2004.005.063

Abstract A micromechanical unit-cell model was developed for 2/2-twill woven fabric composites so that the model could be implemented for the multi-scale micro/macro-mechanical analysis of 2/2-twill composite structures. The unit-cell model can compute effective material properties of a 2/2-twill composite and decompose the effective stresses (strains) of the woven fabric composite into the stresses (strains) of the tows. When this unit-cell module is incorporated into the multi-scale analysis by combining with other modules developed previously, the residual strength and stiffness of a laminated structure made of 2/2-twill woven fabric composites can be predicted along with damage progression in the structure. Damage… More >