Virginia Aragon Sanabria¹, Cheng Dong^*

Molecular & Cellular Biomechanics, Vol.15, No.1, pp. 1-19, 2018, DOI:10.3970/mcb.2018.015.001

Abstract Endothelial barrier function is critical for tissue homeostasis throughout the body. Disruption of the endothelial monolayer leads to edema, vascular diseases and even cancer metastasis among other pathological conditions. Breakdown of the endothelial barrier integrity triggered by cytokines (e.g.IL-8,IL-1β) and growth factors (e.g.VEGF) is well documented. However, endothelial cells are subject to major biomechanical forces that affect their behavior. Due to their unique location at the interface between circulating blood and surrounding tissues, endothelial cells experience shear stress, strain and contraction forces. More than three decades ago, it was already appreciated that shear flow caused endothelial cells alignment in the… More >

Baogang Tian¹, Yang Shao¹, Zhijiong Wang¹, Jian Li^2,*

Molecular & Cellular Biomechanics, Vol.14, No.3, pp. 187-194, 2017, DOI:10.3970/mcb.2017.014.187

Abstract The purpose of this study was to explore the clinical efficacy and safety of posterior pedicle screw fixation in the treatment of thoracolumbar burst fracture. A total of 120 patients with thoracolumbar burst fractures were selected from January 2014 to December 2016. 60 patients were divided into the study group, and 60 patients were as the control group. The patients in the study group were treated with posterior pedicle screw fixation. The control group was treated with posterior non-traumatic pedicle screw fixation. After treatment, there were six months follow up. The clinical indexes, complications, and the anterior aspect height ratio,… More >

Geert W. Schmid-Schönbein^*

Molecular & Cellular Biomechanics, Vol.5, No.2, pp. 83-96, 2008, DOI:10.3970/mcb.2008.005.083

Abstract Increasing evidence suggests that most cardiovascular diseases, tumors and other ailments are associated with an inflammatory cascade. The inflammation is accompanied by activation of cells in the circulation and fundamental changes in the mechanics of the microcirculation, expression of pro-inflammatory genes and downregulation of anti-inflammatory genes, attachment of leukocytes to the endothelium, elevated permeability of the endothelium, and many other events. The evidence has opened great opportunities for medicine to develop new anti-inflammatory interventions. But it also raises a fundamental question: What is the origin of inflammation? I will discuss a basic series of studies that was designed to explore… More >

Leiting Dong¹, Satya N. Atluri1¹

CMC-Computers, Materials & Continua, Vol.30, No.1, pp. 39-82, 2012, DOI:10.3970/cmc.2012.030.039

Abstract In this paper, as an extension to the authors's work in [Dong and Atluri (2011a,b, 2012a,b,c)], three-dimensional Trefftz Voronoi Cells (TVCs) with ellipsoidal voids/inclusions are developed for micromechanical modeling of heterogeneous materials. Several types of TVCs are developed, depending on the types of heterogeneity in each Voronoi Cell(VC). Each TVC can include alternatively an ellipsoidal void, an ellipsoidal elastic inclusion, or an ellipsoidal rigid inclusion. In all of these cases, an inter-VC compatible displacement field is assumed at each surface of the polyhedral VC, with Barycentric coordinates as nodal shape functions. The Trefftz trial displacement fields in each VC are… More >

L. Dong¹, S. N. Atluri¹

CMC-Computers, Materials & Continua, Vol.29, No.2, pp. 169-212, 2012, DOI:10.3970/cmc.2012.029.169

Abstract In this paper, three-dimensionalT-Trefftz Voronoi Cell Finite Elements (VCFEM-TTs) are developed for micromechanical modeling of heterogeneous materials. Several types of VCFEMs are developed, depending on the types of heterogeneity in each element. Each VCFEM can include alternatively a spherical void, a spherical elastic inclusion, a spherical rigid inclusion, or no voids/inclusions at all.In all of these cases, an inter-element compatible displacement field is assumed at each surface of the polyhedral element, with Barycentric coordinates as nodal shape functions.The T-Trefftz trial displacement fields in each element are expressed in terms of the Papkovich-Neuber solution. Spherical harmonics are used as the Papkovich-Neuber… More >

Mohammed A. Mohammed¹, Andre R. Barbosa^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 583-627, 2019, DOI:10.32604/cmes.2019.06052

Abstract A three-dimensional nonlinear modeling strategy for simulating the seismic response of slender reinforced concrete structural walls with different cross-sectional shapes is presented in this paper. A combination of nonlinear multi-layer shell elements and displacement-based beam-column elements are used to model the unconfined and confined parts of the walls, respectively. A uniaxial material model for reinforcing steel bars that includes buckling and low-cyclic fatigue effects is used to model the longitudinal steel bars within the structural walls. The material model parameters related to the buckling length are defined based on an analytical expression for reinforcing steel bars embedded in reinforced concrete… More >

Junjun Jiang¹, Congqing Wang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.1, pp. 105-121, 2019, DOI:10.32604/cmes.2019.06277

Abstract Aircraft skin health concerns whether the aircraft can fly safely. In this paper, an improved mechanical structure of the aircraft skin inspection robot was introduced. Considering that the aircraft skin surface is a curved environment, we assume that the curved environment is equivalent to an inclined plane with a change in inclination. Based on this assumption, the Cartesian dynamics model of the robot is established using the Lagrange method. In order to control the robot’s movement position accurately, a position backstepping control scheme for the aircraft skin inspection robot was presented. According to the dynamic model and taking into account… More >

Letícia Fleck Fadel Miguel¹, Leandro Fleck Fadel Miguel², João Kaminski Jr.³

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.2, pp. 87-104, 2015, DOI:10.3970/cmes.2015.104.086

Abstract Since the half of the XX century, attention was given to the instability of structures under parametric excitation, especially under periodic loads. On the other hand, the instability of bars subjected to axial loads of impulsive type has been little studied, in spite of the practical importance of the topic. Thus, in Engineering Design it is frequently supposed, without tests or additional verifications, that an axial load of short duration can exceed the Euler critical load of the bar without inducing damage in the same.
Within this context, this paper proposes the use of the truss-like Discrete Element Method… More >

Emrah Yilmaz¹, Hikmet Koyunbakan²

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.6, pp. 463-471, 2014, DOI:10.3970/cmes.2014.099.463

Abstract In this study, Ambarzumyan’s theorem for quadratic Sturm-Liouville problem is extended to second order differential systems of dimension d ≥ 2. It is shown that if the spectrum is the same as the spectrum belonging to the zero potential, then the matrix valued functions both P(x) and Q(x) are zero by imposing a condition on P(x). In scaler case, this problem was solved in [Koyunbakan, Lesnic and Panakhov (2013)]. More >

Chein-Shan Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.4, pp. 375-407, 2014, DOI:10.3970/cmes.2014.098.375

Abstract In this paper we study the nonlinear dynamical system x^·=f(x,t) from a newly developed theory, viewing the time-varying function of sign(||f||²||x||²− 2(f·x)²) = −sign(cos 2θ) as a key factor, where θ is the intersection angle between x and f. It together with sign(cos θ) can reveal the complexity of nonlinear Duffing oscillator and a quadratic ship rolling oscillator. The barcode is formed by plotting sign(||f||²||x||²− 2(f·x)²) with respect to time. We analyze the barcode to point out the bifurcation of subharmonic motions and the range of chaos in the parameter space. The bifurcation diagram obtained by plotting the percentage… More >