Xu Liu¹, Xiaoyang Chen^{1, *}, Rongyu Kang¹, Xuejin Shen¹, Ben Ni²

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 129-152, 2020, DOI:10.32604/cmes.2020.07836 - 01 April 2020

Abstract In this paper, the oscillatory oil squeeze film is taken as a research object, and a coupled cavitation model based on the theory of bubble dynamics and hydrodynamic lubrication is used and a specific method of numerical calculation is given. Then the parallel-plate squeeze film test apparatus is used to validate the coupled cavitation model. The pictures of the cavitation were captured by a high-speed camera and then processed to obtain the variation of the cavitation area in experiments. Compared with the experimental results, the model can successfully predict the process of generation and development… More >

Meijuan Shan^{1, 2}, Libin Zhao^{2, *}, Wei Huang³, Fengrui Liu², Jianyu Zhang^{4, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 101-127, 2020, DOI:10.32604/cmes.2020.09099 - 01 April 2020

Abstract The high demands for load-carrying capability and structural efficiency of composite-metal bolted joints trigger in-depth investigations on failure mechanisms of the joints in hygrothermal environments. However, few studies have been presented to exhaustively reveal hygrothermal effects on the failure of CFRP-metal bolted joints, which differ from CFRP-CFRP or metal-metal bolted joints because of the remarkably different material properties of CFRPs and metals. In this paper, hygrothermal effects on tensile failures of single-lap and double-lap CFRP-aluminum bolted joints were experimentally and numerically investigated. A novel numerical model, in which a hygrothermal-included progressive damage model of composites… More >

Min Luo¹, Tingting Xu^{1, *}, Jiajun Jiang², Xu Chi³, Jing Wang⁴, Shihua Xue¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 75-100, 2020, DOI:10.32604/cmes.2020.09236 - 01 April 2020

Abstract The lack of research on flexible drilling tool leads to limited application of ultra-short radius horizontal wells. The flexible drilling tool is different from the conventional drilling tool. The flexible drilling pipe involves a mutual transition between the structure and the mechanism during the deformation process. At the same time, the flexible drilling pipe and the eccentric guide tube, the guide tube and the wellbore generate random contact. In this paper, 3-D beam elements, universal joint elements, rigid beam elements and the beam-beam contact elements are combined to establish a two-layer contact nonlinear finite element… More >

Jianhua Dong¹, Lifeng Wu², Xiaogang Liu^{1, *}, Cheng Fan¹, Menghui Leng³, Qiliang Yang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 49-73, 2020, DOI:10.32604/cmes.2020.09014 - 01 April 2020

Abstract Solar radiation is an important parameter in the fields of computer modeling, engineering technology and energy development. This paper evaluated the ability of three machine learning models, i.e., Extreme Gradient Boosting (XGBoost), Support Vector Machine (SVM) and Multivariate Adaptive Regression Splines (MARS), to estimate the daily diffuse solar radiation (R_d). The regular meteorological data of 1966-2015 at five stations in China were taken as the input parameters (including mean average temperature (T_a), theoretical sunshine duration (N), actual sunshine duration (n), daily average air relative humidity (RH), and extra-terrestrial solar radiation (R_a)). And their estimation accuracies were subjected to… More >

Davide Piovesan^{1, *}, Roberto Bortoletto²

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 23-47, 2020, DOI:10.32604/cmes.2020.09231 - 01 April 2020

Abstract Exoskeletons are designed to control the forces exerted during the physical coupling between the human and the machine. Since the human is an active system, the control of an exoskeleton requires coordinated action between the machine and the load so to obtain a reciprocal adaptation. Humans in the control loop can be modeled as active mechanical loads whose stiffness is continuously changing. The direct measurement of human stiffness is difficult to obtain in real-time, thus posing a significant limitation to the design of wearable robotics controllers. Electromyographic (EMG) recordings can provide an indirect estimation of… More >

Primož Kocutar^{1, *}, Jure Ravnik¹, Leopold Škerget¹

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 1-22, 2020, DOI:10.32604/cmes.2020.08728 - 01 April 2020

Abstract In this paper, we develop and test a unified hybrid LES/URANS turbulence model with two different Large Eddy Simulation (LES) turbulence models. The numerical algorithm is based on the Boundary Element Method. In the existing hybrid LES/URANS turbulence model we implemented a new Smagorinsky LES turbulence model. The hybrid LES/URANS turbulence model is unified, which means that the LES/URANS interface is changed dynamically during simulation using a physical quantity. In order to define the interface between LES and unsteady Reynolds Averaged Navier Stokes (URANS) zones during the simulation, we use the Reynolds number based on… More >

Rafi Mazor^1,*, Meital Mazor², Ali E. Dabiri^2,3, Bhavesh Patel², Ghassan S. Kassab²

Molecular & Cellular Biomechanics, Vol.17, No.2, pp. 93-99, 2020, DOI:10.32604/mcb.2019.08267

Abstract Cryotherapy, or more commonly known as cold therapy, is the use of low temperatures in medical treatment. The most prominent use of cryotherapy is for cryosurgery where application of very low temperatures is used to ablate diseased tissue (e.g., most commonly in dermatology). Recent research, however, shows that low temperature may modulate collagen fibers beyond the already known effects of extreme cooling on joint pain relieve and inflammation. The goal of this brief review is to outline the known effects of extreme cooling on molecular, fiber and cell physiology and to leverage these properties in… More >

Lujie Chen¹, Liang Zheng¹, Maosen Lian¹, Shouhua Luo^1,*

Molecular & Cellular Biomechanics, Vol.17, No.2, pp. 85-92, 2020, DOI:10.32604/mcb.2019.07386

Abstract Micro-CT provides a high-resolution 3D imaging of micro-architecture in a non-invasive way, which becomes a significant tool in biomedical research and preclinical applications. Due to the limited power of micro-focus X-ray tube, photon starving occurs and noise is inevitable for the projection images, resulting in the degradation of spatial resolution, contrast and image details. In this paper, we propose a C-GAN (Conditional Generative Adversarial Nets) denoising algorithm in projection domain for Micro-CT imaging. The noise statistic property is utilized directly and a novel variance loss is developed to suppress the blurry effects during denoising procedure.… More >

Ali E. Dabiri^1,2,*, Erik Samwel³, Ghassan S. Kassab¹

Molecular & Cellular Biomechanics, Vol.17, No.2, pp. 75-83, 2020, DOI:10.32604/mcb.2020.08775

Abstract Nearly two billion people are afflicted with iron deficiency and approximately 300 million children globally have anemia. Most of those affected are unaware of their lack of iron, in part because detection of iron deficiency requires a blood test. It is becoming increasingly important to screen these individuals to reduce medical cost and avoid chronic disease conditions. There are limited settings of laboratory infrastructure for standard blood-based tests around the world to routinely accomplish this important screening test. We propose a new concept to use either human hair or nail as a screening method to… More >

Shicheng He¹, Juhui Qiu¹, Wanling Liu¹, Tieying Yin¹, Dechuan Zhang^2,*, Donghua Liao^3,4, Haijun Zhang⁵, Yuxia Yin⁵, Guixue Wang^1,*

Molecular & Cellular Biomechanics, Vol.17, No.2, pp. 63-74, 2020, DOI:10.32604/mcb.2020.08750

Abstract Computational fluid dynamics (CFD) has been widely used for studying intracranial aneurysm hemodynamics, while its use for guiding clinical strategy is still in development. In this study, CFD simulations helped inform treatment decision for a middle cerebral artery (MCA) aneurysm case was investigated. A patient with a 10.4 × 9.8 mm aneurysm attached with a small aneurysm at the edge of the trifurcation in the left MCA was included in this study. For removing the MCA aneurysm, two scenarios were considered: Plan-A involved clipping the small aneurysm and Plan-B involved clipping the whole aneurysm. A… More >