Yingjun Wang^1,*, Zhenpei Wang^2,*, Zhaohui Xia³, Leong Hien Poh²

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.3, pp. 455-507, 2018, DOI:10.31614/cmes.2018.04603

Abstract Isogeometric analysis (IGA), an approach that integrates CAE into conventional CAD design tools, has been used in structural optimization for 10 years, with plenty of excellent research results. This paper provides a comprehensive review on isogeometric shape and topology optimization, with a brief coverage of size optimization. For isogeometric shape optimization, attention is focused on the parametrization methods, mesh updating schemes and shape sensitivity analyses. Some interesting observations, e.g. the popularity of using direct (differential) method for shape sensitivity analysis and the possibility of developing a large scale, seamlessly integrated analysis-design platform, are discussed in the framework of isogeometric shape… More >

Adrien Scheuer^{1, 3, *}, Amine Ammar², Emmanuelle Abisset-Chavanne³, Elias Cueto⁴, Francisco Chinesta⁵, Roland Keunings¹, Suresh G. Advani⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.3, pp. 367-386, 2018, DOI:10.31614/cmes.2018.04278

Abstract Describing the orientation state of the particles is often critical in fibre suspen-sion applications. Macroscopic descriptors, the so-called second-order orientation tensor (or moment) leading the way, are often preferred due to their low computational cost. Clo-sure problems however arise when evolution equations for the moments are derived from the orientation distribution functions and the impact of the chosen closure is often unpre-dictable. In this work, our aim is to provide macroscopic simulations of orientation that are cheap, accurate and closure-free. To this end, we propose an innovative data-based approach to the upscaling of orientation kinematics in the context of fibre… More >

Yang Yang^1,*, Jinbao Duan¹, Haitao Yu¹, Zhipeng Gao¹, Xuesong Qiu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.3, pp. 555-575, 2018, DOI:10.31614/cmes.2018.04249

Abstract The development of deep learning has revolutionized image recognition technology. How to design faster and more accurate image classification algorithms has become our research interests. In this paper, we propose a new algorithm called stochastic depth networks with deep energy model (SADIE), and the model improves stochastic depth neural network with deep energy model to provide attributes of images and analysis their characteristics. First, the Bernoulli distribution probability is used to select the current layer of the neural network to prevent gradient dispersion during training. Then in the backpropagation process, the energy function is designed to optimize the target loss… More >

Qi Zhang¹, Bin Gao¹, Yue Shi¹, Chang Yu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 247-262, 2018, DOI: 10.31614/cmes.2018.04082

Abstract Although pulsatile ECMO, as novel kinds of ECMO, has been attracted more and more attention, the differences of the hemodynamic effects of the pulsatile ECMO on the aorta, the cerebral perfusion, and left ventricular work were still under-investigated. The aim of this study was to clarify the hemodynamic differences of the cardiovascular system between the pulsatile and non-pulsatile VA ECMO. In this study, three ECMO support modes, named as “constant flow mode”, “co-pulse mode” and “counter pulse mode”, were designed. The computational fluid dynamics (CFD) study was carried out. The distribution of the oxygenated blood, the blood velocity vector, the… More >

Wei Wei¹, Qingsheng Yang^2,*, Xia Liu², Xiaoqiao He^3,*, Kim-Meow Liew³

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 387-409, 2018, DOI: 10.3970/cmes.2018.01856

Abstract In this paper, by introducing a chemical field, the J-integral formulation is presented for the chemo-mechanical coupled medium based on the laws of thermodynamics. A finite element implementation of the J-integral was performed to study the mode I chemo-mechanical coupled fracture problem. For derivation of the coupled J-integral, the equivalent domain integral (EDI) method was applied to obtain the mode I J-integral, with expression of the area integrals based on constitutive relationships of a linear elastic small deformation for chemo-mechanical coupling, instead of the finite deformation problem. A finite element procedure is developed to compute the mode I J-integral, and… More >

A. M. E. Ramírez-Mendoza¹

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 295-311, 2018, DOI: 10.3970/cmes.2018.00239

Abstract A spike response model (SRM) based on the spikes generator circuit (SGC) of adaptive fuzzy spiking neurons (AFSNs) is developed. The SRM is simulated in MatlabTM environment. The proposed model is applied to a configuration of a fuzzy exclusive or (fuzzy XOR) operator, as an illustrative example. A description of the comparison of AFSNs with other similar methods is given. The novel method of the AFSNs is used to determine the value of the weights or parameters of the fuzzy XOR, first with dynamic weights or self-tuning parameters that adapt continuously, then with fixed weights obtained after training, finally with… More >

Selmin Ener Rusen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 327-343, 2018, DOI: 10.3970/cmes.2018.00159

Abstract It is very important to determine the daily horizontal global, diffuse and beam irradiations correctly in planning energy systems, in cost analysis, in the atmosphere, and in the productivity evaluations. Besides, the knowledge of accurate solar irradiation is the most important component of the essential climate variables according to the Global Climate Observing System (GCOS) in August 2010. It is known that the changes of these irradiation parameters directly affect our atmosphere and cloud formation processes. Turkey is one of the countries, which has high solar energy potential by reason of its climatic and regional factors. Especially, Konya and Karaman… More >

C. Gopinath^{1, *}, M. Rajvikram¹

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 359-386, 2018, DOI: 10.3970/cmes.2018.06143

Abstract This research paper proposes a single phase fifteen level inverter for a grid connected PV system. The proposed inverter is also called cascaded asymmetric multilevel inverter. By adopting appropriate hybrid modulation technique improved output voltage is obtained with minimum number of power electronic switches. By reducing the number of gate triggering circuits of the switches, the size and power consumption of the driving circuits can be reduced. The total harmonic distortion of the output of the inverter is improved by this inverter. The proposed inverter developed by cascading a full bridge inverter with modified H bridge multilevel inverter. The validity… More >

Maohui Xia¹, Jin Li^*,2

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 313-326, 2018, DOI: 10.3970/cmes.2018.08053

Abstract In this paper, the classical composite middle rectangle rule for the computation of Cauchy principal value integral (the singular kernel 1/(x-s)) is discussed. With the density function approximated only while the singular kernel is calculated analysis, then the error functional of asymptotic expansion is obtained. We construct a series to approach the singular point. An extrapolation algorithm is presented and the convergence rate of extrapolation algorithm is proved. At last, some numerical results are presented to confirm the theoretical results and show the efficiency of the algorithms. More >

Yi Xue^1,2,*, Faning Dang², Rongjian Li², Fei Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 345-358, 2018, DOI: 10.3970/cmes.2018.08052

Abstract Adsorption deformation significantly affects the seepage characteristics of coal. However, effect of sorption time on coal permeability and gas pressure has not been investigated systematically. In this study, the sorption experiment of coal samples is conducted to elaborate the importance of sorption equilibration time. Then a coupled coal deformation and gas flow model is established considering the sorption characteristic and permeability evolution. This coupled model is implemented through finite element method to analyze the effect of sorption time on coal permeability and gas pressure. The simulation results reveal that the gas pressure of the coal will change with the adsorption… More >