S. Kobayashi¹, J. Ji¹, H. Morikawa¹, D. Tang², D. N. Ku³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 169-174, 2008, DOI:10.3970/icces.2008.006.169

Abstract The increase of the blood velocity in the distal side of the stenosis causes negative transmural pressure, and atheroscrerotic plaque is compressed, furthermore, the stenosis may cause the collpase which leads the rupture of the plaque. The resultant compression may be important in the development of atherosclerotic plaque fracture and subsequent thrombosis or distal embolization. We have developed stenosis models made of polyvinyl alcohol hydrogel, which closely approximate an arterial disease situation, and performed pulsatile flow experiments. Valsalva's maneuver and cough cause a sharp rise in jugular venous pressure to greater than 50 mmHg. Such More >

Benjamin L. Wong^*, Won C. Bae^*, Kenneth R. Gratz^*, Robert L. Sah^∗,†

Molecular & Cellular Biomechanics, Vol.5, No.3, pp. 197-206, 2008, DOI:10.3970/mcb.2008.005.197

Abstract During joint articulation, the biomechanical behavior of cartilage not only facilitates load-bearing and low-friction, but also provides regulatory cues to chondrocytes. Elucidation of cartilage kinematics under combined compression and shearing conditions clarifies these cues in health and disease. The objectives of this study were to elucidate the effects of lubricant, tissue degeneration, and stress relaxation duration on cartilage shear kinematics during articulation. Human osteochondral cores with normal and mildly degenerate surface structures were isolated. Paired blocks from each core were apposed, compressed, allowed to stress relax for 5 or 60 min, and shear tested with… More >

S. Wong, Y. Shie

CMES-Computer Modeling in Engineering & Sciences, Vol.36, No.2, pp. 97-118, 2008, DOI:10.3970/cmes.2008.036.097

Abstract In this paper, we propose a Galerkin-based smoothed particle hydrodynamics (SPH) formulation with moving least-squares meshless approximation, applied to solid mechanics and large deformation. Our method is truly meshless and based on Lagrangian kernel formulation and stabilized nodal integration. The performance of the methodology proposed is tested through various simulations, demonstrating the attractive ability of particle methods to handle severe distortions and complex phenomena. More >

Weiran Yuan^1,2, Yujun Chen^2,3, André Gagalowicz², Kaixin Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.35, No.2, pp. 133-156, 2008, DOI:10.3970/cmes.2008.035.133

Abstract In this paper we present an approach to cloth simulation which models the deformation based on continuum mechanics and discretized with Meshless Local Petrov-Galerkin (MLPG) Method. MLPG method, which involves not only a meshless interpolation for trial functions, but also a meshless integration of the local weak form, has been considered as a general basis for the other meshless methods. By this way, the mechanical behavior of cloth is consistent and united, which is independent of the resolutions. At the same time, point sampled models, which neither have to store nor to maintain globally consistent… More >

H.M. Lee¹, H.S. Park^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.29, No.1, pp. 29-44, 2008, DOI:10.3970/cmes.2008.029.029

Abstract This paper presents a computational model to estimate deformed shapes of beam structures using 3D coordinate information from terrestrial laser scanning (TLS). The model is composed of five components: 1) formulation of polynomial shape function, 2) application of boundary condition, 3) inducement of compatibility condition, 4) application of the least square method and 5) evaluation of error vector and determination of reasonable polynomial shape function. In the proposed model, the optimal degree of polynomial function is selected based on the complexity of beam structures, instead of using a specific degree of polynomial function. The chosen More >

Adan Vega¹, Sherif Rashed², Yoshihiko Tango³, Morinobu Ishiyama³, Hidekazu Murakawa²

CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.1, pp. 1-14, 2008, DOI:10.3970/cmes.2008.028.001

Abstract Experimental observations have shown that the inherent deformation produced by multi-heating lines is not a simple addition of the inherent deformation produced by single heating lines. Therefore, to accurately predict inherent deformation, the method of superposing inherent deformation of single heating lines is not appropriate. To overcome this difficulty, the authors investigate the influence of multi-heating lines on line heating inherent deformation. First, the influence of previous heating lines on inherent deformation of overlapping, parallel and crossing heating lines is clarified. The influence of the proximity to plate side edge on inherent deformation is also More >

Arun K. Nair¹, Diana Farkas², Ronald D. Kriz¹

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 239-248, 2008, DOI:10.3970/cmes.2008.024.239

Abstract The indentation response of Ni thin films of thicknesses in the nano scale was studied using molecular dynamics simulations with embedded atom method (EAM) interatomic potentials. Simulations were performed in single crystal films in the [111] orientation with thicknesses of 7nm and 33nm. In the elastic regime, the loading curves observed start deviating from the Hertzian predictions for indentation depths greater than 2.5% of the film thickness. The observed loading curves are therefore dependent on the film thickness. The simulation results also show that the contact stress necessary to emit the first dislocation under the More >

V. Shevtsova^1,2, A. Mialdun¹, C. Ferrera^1,4, M. Ermakov^3,4, J. M. Montanero⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 43-54, 2008, DOI:10.3970/fdmp.2008.004.043

Abstract Dynamic free surface deformations induced by buoyant and thermocapillary convection in liquid bridges of 5cSt silicone oil are studied experimentally and numerically. The experiments are performed in ground conditions and static deformation is unavoidable. Convective motion starts in the liquid bridge as soon as ΔT ≠ 0 and initially leads to a stationary dynamic deformation of the free surface. Oscillatory motion starts at a critical value of ΔT and causes oscillations of the interface. The final supercritical shape of the free surface is a result of the static shape with superimposed subcritical stationary and oscillatory dynamic deformations. More >

Ren Jiusheng¹

CMC-Computers, Materials & Continua, Vol.7, No.1, pp. 25-32, 2008, DOI:10.3970/cmc.2008.007.025

Abstract Elastic instability for the inflation and deflation of a thin-walled spherical rubber balloon is examined within the framework of finite pseudo-elasticity. When a spherical rubber balloon is inflated, it is subject to a complex deformation after a pressure maximum has been obtained. One part of the balloon is lightly stretched while the remainder becomes highly stretched. So an aspherical deformation is observed after the initial spherical inflation. A pseudo-elastic strain energy function including a damage variable which may model the loading, unloading and reloading of rubber is used. The balloon is idealized as an elastic More >

Y. Kato, Y. Yamamura

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 87-92, 2007, DOI:10.3970/icces.2007.004.087

Abstract The purpose of this study is to investigate the deformational behavior and strength of the catheter which is made from the soft nylon resin and is reinforced with thin stainless wires called braid. When we image the usage conditions of catheter in the actual surgical operation, it is expected that the multi-axial loading for tension, torsion and the bending are applied and deformations occurring in the catheter become very complicated. As the first step of this study to reveal these phenomena, the combined loadings for tension and torsion are chosen as the subject of this More >