Jinshan Lin^a*, Chunhong Dou^b, Qianqian Wang^a

Sound & Vibration, Vol.52, No.2, pp. 11-15, 2018, DOI:10.32604/sv.2018.03653

Abstract A method for gearbox fault diagnosis consists of feature extraction and fault identification. Many methods for feature extraction have been devised for exposing nature of vibration data of a defective gearbox. In addition, features extracted from gearbox vibration data are identified by various classifiers. However, existing literatures leave much to be desired in assessing performance of different combinatorial methods for gearbox fault diagnosis. To this end, this paper evaluated performance of several typical combinatorial methods for gearbox fault diagnosis by associating each of multifractal detrended fluctuation analysis (MFDFA), empirical mode decomposition (EMD) and wavelet transform (WT) with each of neural… More >

T. Podoba¹, L. Tomsu¹, K. Vlcek¹, M. Heczko

The International Conference on Computational & Experimental Engineering and Sciences, Vol.15, No.4, pp. 111-122, 2010, DOI:10.3970/icces.2010.015.111

Abstract Surface reconstruction based on chaotic systems or exactly given point clouds is very difficult area. Current algorithms such as Marching Cube or Voronoi Filtering do not use methods based on artificial intelligence. In this paper, we investigate solution of polygonal surface construction based on AI. The main purpose is to generate complex polygonal mesh structures based on strange attractors with fractal structure. Attractors have to be created as 4D objects using quaternion algebra or using methods of AI. Polygonal mesh can have different numbers of polygons because of iterative application of this system. Our main goal is to develop new… More >

R.M. Reddy¹, B.N. Rao²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.4, pp. 149-150, 2009, DOI:10.3970/icces.2009.012.149

Abstract Probabilistic fracture mechanics (PFM) blends the theory of fracture mechanics and the probability theory provides a more rational means to describe the actual behavior and reliability of structures. However in PFM, the fracture parameters and their derivatives are often required to predict the probability of fracture initiation and/or instability in cracked structures. The calculation of the derivatives of fracture parameters with respect to load and material parameters, which constitutes size-sensitivity analysis, is not unduly difficult. However, the evaluation of response derivatives with respect to crack size was a challenging task, since it requires shape sensitivity analysis [1]. Using a brute-force… More >

Yong Huang¹, Hui Li¹, Jinping Ou^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.2, pp. 53-64, 2009, DOI:10.3970/icces.2009.012.053

Abstract A new damage identification method based on Fractal theory and wavelet packet transform is presented in the paper. The damage identification method utilize frequency-based domain message, time-based domain message and space based domain message effectively. NeXT method were first employed to reduce loading effect of random vibration measured from structures and then the vibration sinal were decomposed into the certain level wavelet packet components. For every time array of wavelet packet component then need to calculate the mean FD values as the ultimated FD values to reduce noise effect. The location of damage in the beam can be determined by… More >

Kuo Xu¹, Yuan Yuan^1,*, Lihua Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.3, pp. 459-480, 2019, DOI:10.32604/cmes.2019.04677

Abstract Based on the fractal theory, a normal contact stiffness model is established. In the model, the asperity is initially in elastic deformation under contact interference. As the interference is increased, a transition from elastic to elastoplastic to full plastic deformation occurs in this order. The critical elastic interference, the first elastoplastic critical interference and the second elastoplastic critical interference are scale-dependent. According to the truncated asperity size distribution function, the relations between the total normal contact stiffness and the total contact load are obtained. The results show the total normal contact stiffness depends on the range of frequency indexes of… More >

Yonggang Duan¹, Ting Lu¹, Mingqiang Wei¹, Boming Yu², Zhelun Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.6, pp. 481-504, 2015, DOI:10.3970/cmes.2015.109.481

Abstract Analysis of Buckley-Leverett solution in fractal porous medium does prediction of water saturation profile a favor. On the approximation that porous medium consists of a bundle of tortuous capillaries, a physical conceptual Buckley- Leverett model of transient two-phase flow in fractal porous medium is developed based on the fractal characteristics of pore size distribution. The relationship between water saturation and distance is presented according to Buckley-Leverett solution, and the proposed Buckley-Leverett expression is the function of fractal structural parameters (such as pore fractal dimension, tortuosity fractal dimension, maximum and minimum diameters of capillaries) and fluid properties (such as viscosity, contact… More >

K. Umesh¹, R. Ganguli¹

CMC-Computers, Materials & Continua, Vol.41, No.3, pp. 215-240, 2014, DOI:10.3970/cmc.2014.041.215

Abstract Fractal dimension based damage detection method is investigated for a composite plate with random material properties. Composite material shows spatially varying random material properties because of complex manufacturing processes. Matrix cracks are considered as damage in the composite plate. Such cracks are often seen as the initial damage mechanism in composites under fatigue loading and also occur due to low velocity impact. Static deflection of the cantilevered composite plate with uniform loading is calculated using the finite element method. Damage detection is carried out based on sliding window fractal dimension operator using the static deflection. Two dimensional homogeneous Gaussian random… More >