Ryota Misawa^*,1, Sunghoon Lim¹, Shinichi Maruyama¹, Takayuki Yamada¹, Kazuhiro Izui¹, Shinji Nishiwaki¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 28-28, 2019, DOI:10.32604/icces.2019.05203

Abstract Multi-material design, where more than one material is placed in appropriate configurations, is indispensable to reduce weights of mechanical components while keeping their required performances. Multi-material topology optimization is a promising method for realizing such efficient multi-material designs.
The present authors’ group has been developing a multi-material topology optimization method using level set functions and reaction diffusion equations. In this method, multiple level set functions are used to represent the geometrical structure (i.e., shape and topology) and distribution of materials according to the MM-LS (Multi-Material Level Set) model. Then, each level set function is updated using… 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… More >

Ying Zhao¹, Mohammad Noori^1,2, Wael A. Altabey^1,3,*, Ramin Ghiasi⁴, Zhishen Wu¹

Structural Durability & Health Monitoring, Vol.13, No.1, pp. 85-103, 2019, DOI:10.32604/sdhm.2019.04695

Abstract This paper introduces a stiffness reduction based model developed by the authors to characterize accumulative fatigue damage in unidirectional plies and (0/θ/0) composite laminates in fiber reinforced polymer (FRP) composite laminates. The proposed damage detection model is developed based on a damage evolution mechanism, including crack initiation and crack damage progress in matrix, matrix-fiber interface and fibers. Research result demonstrates that the corresponding stiffness of unidirectional composite laminates is reduced as the number of loading cycles progresses. First, three common models in literatures are presented and compared. Tensile viscosity, Young’s modulus and ultimate tensile stress… More >

Mingzhi Luo¹, Kai Ni¹, Peili Yu¹, Yang Jin², Lei Liu¹, Jingjing Li¹, Yan Pan¹, Linhong Deng^1,*

Molecular & Cellular Biomechanics, Vol.16, No.2, pp. 141-151, 2019, DOI:10.32604/mcb.2019.06756

Abstract Airway hyperresponsiveness (AHR) is the cardinal character of asthma, which involves the biomechanical properties such as cell stiffness and traction force of airway smooth muscle cells (ASMCs). Therefore, these biomechanical properties comprise logical targets of therapy. β2-adrenergic agonist is currently the mainstream drug to target ASMCs in clinical practice for treating asthma. However, this drug is known for side effects such as desensitization and non-responsiveness in some patients. Therefore, it is desirable to search for new drug agents to be alternative of β2-adrenergic agonist. In this context, sanguinarine, a natural product derived from plants such… More >

Shaoxiong Yang¹, Yingxin Qi², Zonglai Jiang², Xiaobo Gong^1,*

Molecular & Cellular Biomechanics, Vol.16, No.1, pp. 13-26, 2019, DOI:10.32604/mcb.2019.06096

Abstract Vascular diseases during aging process are closely correlated to the age-related changes of mechanical stimuli for resident cells. Characterizing the variations of mechanical environments in vessel walls with advancing age is crucial for a better understanding of vascular remodeling and pathological changes. In this study, the mechanical stress, strain, and wall stiffness of the femoropopliteal arteries (FPAs) were compared among four different age groups from adolescent to young, middle-aged, and aged subjects. The material parameters and geometries adopted in the FPA models were obtained from published experimental results. It is found that high mechanical stress More >

Zejun Han¹, Hongyuan Fang^2,3,4,*, Juan Zhang⁵, Fuming Wang^2,3,4

CMC-Computers, Materials & Continua, Vol.59, No.3, pp. 853-871, 2019, DOI:10.32604/cmc.2019.03839

Abstract The pavement layered structures are composed of surface layer, road base and multi-layered soil foundation. They can be undermined over time by repeated vehicle loads. In this study, a hybrid numerical method which can evaluate the displacement responses of pavement structures under dynamic falling weight deflectometer (FWD) loads. The proposed method consists of two parts: (a) the dynamic stiffness matrices of the points at the surface in the frequency domain which is based on the domain-transformation and dual vector form equation, and (b) interpolates the dynamic stiffness matrices by a continues rational function of frequency. More >

Ying Zhou^1,*, Peng Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 759-777, 2019, DOI:10.32604/cmes.2019.04383

Abstract This paper proposes a novel three-dimensional (3D) isolation system for facilities and presents the numerical simulation approach for the isolated system under earthquake excitations and impact effect using the OpenSees (Open System for Earthquake Engineering Simulation) software frame work. The 3D isolators combine the quasi-zero stiffness (QZS) system in the vertical direction and lead rubber bearing in the horizontal direction. Considering the large aspect ratio of the isolated facility, linear viscous dampers are designed in the vertical direction to diminish the overturning effect. The vertical QZS isolation system is characterized by a cubic force-displacement relation,… More >

Thanh Q. Nguyen^1,2, Thao T. D. Nguyen³, H. Nguyen-Xuan^4,5,*, Nhi K. Ngo^1,2

CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 27-53, 2019, DOI:10.32604/cmc.2019.07756

Abstract This paper presents a new approach using correlation and cross-correlation coefficients to evaluate the stiffness degradation of beams under moving load. The theoretical study of identifying defects by vibration methods showed that the traditional methods derived from the vibration measurement data have not met the needs of the actual issues. We show that the correlation coefficients allow us to evaluate the degree and the effectiveness of the defects on beams. At the same time, the cross-correlation model is the basis for determining the relative position of defects. The results of this study are experimentally conducted More >

Natasha G. Boyes¹, Michael K. Stickland², Stephanie Fusnik¹, Elizabeth Hogeweide¹, Josie T.J. Fries¹, Mark J. Haykowsky³, Chantelle L. Baril¹, Shonah Runalls¹, Ashok Kakadekar⁴, Scott Pharis⁴, Charissa Pockett⁴, Timothy J. Bradley⁴, Kristi D. Wright⁵, Marta Erlandson¹, Corey R. Tomczak¹

Congenital Heart Disease, Vol.13, No.4, pp. 578-583, 2018, DOI:10.1111/chd.12614

Abstract Children with congenital heart disease are at risk for developing increased arterial stiffness and this may be modulated by physical activity. Objective: To compare arterial stiffness in high- and low-physically active children with congenital heart disease and healthy age- and sex-matched controls.
Patients: Seventeen children with congenital heart disease (12 ± 2 years; females = 9), grouped by low- and high-physical activity levels from accelerometry step count values, and 20 matched controls (11 ± 3 years; females = 9) were studied.
Outcome Measures: Carotid-radial pulse wave velocity was assessed with applanation tonometry to determine arterial stiffness. Body composition… More >

Chengquan Wang¹, Yonggang Shen^2,*, Yun Zou¹, Tianqi Li¹, Xiaoping Feng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.1, pp. 75-93, 2018, DOI:10.3970/cmes.2018.114.075

Abstract The failure behavior of the precast prestressed concrete T girder was investigated by destructive test and finite-element analysis, and the mid-span deflection, girder stiffness and the variation of the cross section strain in the loading process were obtained, and the mechanical properties, mechanical behavior, elastic and plastic behavior and ultimate bearing capacity of T girder with large span were revealed. Furthermore, the relationship between the beam stiffness degradation, the neutral axis in cross-section, steel yielding and concrete cracking are investigated and analyzed. A method was proposed to predict the residual bearing capacity of a bridge More >