Lisheng Luo^1,*, Xinran Xie¹, Yongqiang Zhang¹, Xiaofeng Zhang², Xinyue Cui¹

Journal of Renewable Materials, Vol.11, No.2, pp. 791-809, 2023, DOI:10.32604/jrm.2022.022539

Abstract Traditional methods focus on the ultimate bending moment of glulam beams and the fracture failure of materials with defects, which usually depends on empirical parameters. There is no systematic theoretical method to predict the stiffness and shear distribution of glulam beams in elastic-plastic stage, and consequently, the failure of such glulam beams cannot be predicted effectively. To address these issues, an analytical method considering material nonlinearity was proposed for glulam beams, and the calculating equations of deflection and shear stress distribution for different failure modes were established. The proposed method was verified by experiments and numerical models under the corresponding… More > Graphic Abstract

Jie Bai, Xiaowei Zeng^*

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.2, pp. 551-565, 2022, DOI:10.32604/cmes.2022.019376

Abstract Cell migration plays a significant role in many biological activities, yet the physical mechanisms of cell migration are still not well understood. In this study, a continuum physics-based epithelial monolayer model including the intercellular interaction was employed to study the cell migration behavior in a confluent epithelial monolayer at constant cell density. The epithelial cell was modeled as isotropic elastic material. Through finite element simulation, the results revealed that the motile cell was subjected to higher stress than the other jammed cells during the migration process. Cell stiffness was implied to play a significant role in epithelial cell migration behavior.… More >

Radwan Abu-Gdairi¹, Shatha Hasan², Shrideh Al-Omari^3,*, Mohammad Al-Smadi^2,4, Shaher Momani^4,5

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 299-313, 2022, DOI:10.32604/cmes.2022.017010

Abstract In this paper, an efficient multi-step scheme is presented based on reproducing kernel Hilbert space (RKHS) theory for solving ordinary stiff differential systems. The solution methodology depends on reproducing kernel functions to obtain analytic solutions in a uniform form for a rapidly convergent series in the posed Sobolev space. Using the Gram-Schmidt orthogonality process, complete orthogonal essential functions are obtained in a compact field to encompass Fourier series expansion with the help of kernel properties reproduction. Consequently, by applying the standard RKHS method to each subinterval, approximate solutions that converge uniformly to the exact solutions are obtained. For this purpose,… More >

Carlos A. Felippa^*

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1209-1241, 2021, DOI:10.32604/cmes.2021.016803

Abstract This paper considers Lagrangian finite elements for structural dynamics constructed with cubic displacement shape functions. The method of templates is used to investigate the construction of accurate mass-stiffness pairs. This method introduces free parameters that can be adjusted to customize elements according to accuracy and rank-sufficiency criteria. One- and two-dimensional Lagrangian cubic elements with only translational degrees of freedom (DOF) carry two additional nodes on each side, herein called side nodes or SN. Although usually placed at the third-points, the SN location may be adjusted within geometric limits. The adjustment effect is studied in detail using symbolic computations for a… More >

Chao Mei^1,2, Qifu Wang^1,*, Chen Yu¹, Zhaohui Xia¹

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.2, pp. 627-659, 2021, DOI:10.32604/cmes.2021.017704

Abstract This paper presents an effective fiber angle optimization method for two and multi-layered variable stiffness composites. A gradient-based fiber angle optimization method is developed based on isogeometric analysis (IGA). Firstly, the element densities and fiber angles for two and multi-layered composites are synchronously optimized using an extended Bi-layered continuous fiber angle optimization method (XBi-CFAO). The densities and fiber angles in the base layer are attached to the control points. The structure response and sensitivity analysis are accomplished using the non-uniform rational B-spline (NURBS) based IGA. By the benefit of the B-spline space, this method is free from checkerboards, and no… More >

Jian Gong¹, Lingzhi Xie^1,2,*, Yongxue Li¹, Zhichun Ni³, Qingzhu Wei³, Yupeng Wu⁴, Haonan Cheng⁵

Journal of Renewable Materials, Vol.10, No.1, pp. 33-51, 2022, DOI:10.32604/jrm.2021.016262

Abstract Based on the recent development of renewable energy utilization technology, in addition to centralized photovoltaic power plants, distributed photovoltaic power generation systems represented by building-integrated photovoltaic systems are frequently employed for power supply. Therefore, in the architectural design, the double-glass photovoltaic module used in the integrated photovoltaic building system puts forward a higher load-bearing capacity requirement and the corresponding simplified method of carrying capacity check. This article focuses on the simplified method of checking the bearing capacity of the four-sided simply supported double-glass photovoltaic module. First, the principle of equivalent stiffness is used to calculate the effective thickness. Then, the… More > Graphic Abstract

Chao Mei, Qifu Wang^*, Chen Yu, Zhaohui Xia

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 179-202, 2020, DOI:10.32604/cmes.2020.09948

Abstract This paper presents a topology optimization method for variable stiffness composite panels with varying fiber orientation and curvilinear fiber path. Non-uniform rational B-Splines (NURBS) based Isogeometric analysis (IGA) is utilized for the numerical computation of the general minimum compliance problem. The sensitivity analysis of the structure compliance function for the density and bi-layer orientation is conducted. The bi-layer fiber paths in the design domain are generated using streamline method and updated by divided pieces reselection method after the optimization process. Several common examples are tested to demonstrate the effectiveness of the method. The results show that the proposed method can… 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 and 6-min… 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

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 human muscle force and stiffness,… More >

Amirabbas Haidarpour, Kong Fah Tee^*

Structural Durability & Health Monitoring, Vol.14, No.1, pp. 1-17, 2020, DOI:10.32604/sdhm.2020.08792

Abstract This paper provides a model updating approach to detect, locate, and characterize damage in structural and mechanical systems by examining changes in measured vibration responses. Research in vibration-based damage identification has been rapidly expanding over the last few decades. The basic idea behind this technology is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Therefore, changes in the physical properties will cause changes in the modal properties which could be obtained by structural health monitoring (SHM). Updating is a process fraught with numerical difficulties. These… More >