Hans Mühlhaus¹, Laurent Bourgouin¹, Alina Hale¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.4, pp. 225-232, 2007, DOI:10.3970/icces.2007.003.225

Abstract We use a finite element formulation of the level set method to model the evolution of the free surface of axi-symmetric spreading flows of highly viscous media on a horizontal plane. We consider specifically the growth of a lava dome as an example however similar problems also occur in flows involving the spreading of molten metals or ceramics. Here we restrict ourselves on constant viscosity fluids for simplicity. In real lavas or melts the viscosity is highly temperature dependent. This manifests itself in the formation of thin predominantly elastic-plastic boundary layers along the free (cold) More >

J. António¹ , A. Tadeu¹, L. Godinho

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.3, pp. 157-162, 2007, DOI:10.3970/icces.2007.003.157

Abstract A frequency dependent formulation based on the Method of Fundamental Solutions (MFS) is used to simulate the sound wave propagation in a 3D acoustic space. This solution is approximated by a linear combination of fundamental solutions generated by virtual sources placed outside the domain in order to avoid singularities. The coating materials can be assumed to be absorbent. This is achieved in the model prescribing the impedance that is defined as a function of the absorption coefficient. The model is first verified against analytical solutions, provided by the image source technique for a parallelepiped room More >

Darrell W. Pepper¹, Xiuling Wang²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.3, pp. 121-126, 2007, DOI:10.3970/icces.2007.003.121

Abstract This article has no abstract. More >

K.G. Wang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.1, pp. 21-28, 2007, DOI:10.3970/icces.2007.003.021

Abstract A framework of applications of multiscale modeling to property prediction of advanced materials will be briefly presented. A methodology will be shown to link micro-scale to the continuum scale, integrating micro-scale modeling of microstructure with the large Thermo-Calc© database. This paradigm is successfully applied to the case of Fe-12Ni-6Mn maraging steel. We predict the mechanical properties of the maraging steel such as hardness. We found that our predictions in hardness is in agreement with experimental data. More >

M-A Lavoie¹, A. Gakwaya¹, M. Nejad Ensan², D.G. Zimcik²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.4, pp. 111-118, 2007, DOI:10.3970/icces.2007.002.111

Abstract This paper reviews numerical methods that are currently available to simulate bird strike as well as the theory of the event. It also summarizes important parameters and provides guidelines as to how to set up the analysis and how to evaluate a model. The information provided is based on physical properties and available results regarding a bird and its behaviour upon impact. The simulations have been performed with LS-DYNA 970 but can be done in similar dynamic finite elements analysis codes. More >

Dalin Tang¹, Chun Yang², Pedro N. del Nido³, Tal Geva³, Chun Yuan⁴, Tom Hatsukami⁵, Fei Liu⁴, Jie Zheng⁶, Pamela K. Woodard⁶

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.1, pp. 1-6, 2007, DOI:10.3970/icces.2007.001.001

Abstract Image-based computational models for blood flow in the heart and diseased arteries have been developed for disease assessment and potential clinical applications. Models with fluid-structure interactions for human right ventricle (RV) remodeling surgery design, carotid and coronary atherosclerotic plaques and abdominal aortic aneurysm (AAA) were presented. Organ morphology, material properties, governing equations, proper initial and boundary conditions, controlling factors and research focuses for each model were discussed. More >

G. Renaud¹, M. Liao¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.2, pp. 87-92, 2007, DOI:10.3970/icces.2007.001.087

Abstract This paper presents a probabilistic crack growth model developed for the Holistic Structural Integrity Process (HOLSIP) framework. Statistical data, obtained from testing and fractographic analyses of 2024-T3 test coupons, were used to derive the fatigue crack growth material variability. Results showed the relative impact of material variability in the short and long crack regimes. Monte Carlo simulations showed good agreement between analytical life distributions and test results. More >

Nooshin Haghighipour^∗, Mohammad Tafazzoli-Shadpour^∗, Mohammad Ali Shokrgozar^†, Samira Amini^∗, Amir Amanzadeh^†, Mohammad Taghi Khorasani^‡

Molecular & Cellular Biomechanics, Vol.4, No.4, pp. 189-200, 2007, DOI:10.3970/mcb.2007.004.189

Abstract Evaluation of mechanical environment on cellular function is a major field of study in cellular engineering. Endothelial cells lining the entire vascular lumen are subjected to pulsatile blood pressure and flow. Mechanical stresses caused by such forces determine function of arteries and their remodeling. Critical values of mechanical stresses contribute to endothelial damage, plaque formation and atherosclerosis. A device to impose cyclic strain on cultured cells inside an incubator was designed and manufactured operating with different load amplitudes, frequencies, numbers of cycles and ratios of extension to relaxation. Endothelial cells cultured on collagen coated silicon… More >

Dalin Tang^*, Chun Yang^†, Tal Geva^‡,§, Pedro J. del Nido^¶

Molecular & Cellular Biomechanics, Vol.4, No.3, pp. 159-176, 2007, DOI:10.3970/mcb.2007.004.159

Abstract A single-layer isotropic patient-specific right/left ventricle and patch (RV/LV/Patch) combination model with fluid-structure interactions (FSI) was introduced in our previous papers to evaluate and optimize human pulmonary valve replacement/insertion (PVR) surgical procedure and patch design. In this paper, an active anisotropic model with two-layer structure for ventricle wall and tissue fiber orientation was introduced to improve previous isotropic model for more accurate assessment of RV function and potential application in PVR surgery and patch design. A material-stiffening approach was used to model active heart contraction. The computational models were used to conduct ``virtual (computational)'' surgeries More >

Anat Ratnovsky^∗,†, Matthew Mellema^*, Steven S. An^∗,‡, Jeffrey J. Fredberg^*, Stephanie A. Shore^*

Molecular & Cellular Biomechanics, Vol.4, No.3, pp. 143-158, 2007, DOI:10.3970/mcb.2007.004.143

Abstract Obesity is a risk factor for asthma. The purpose of this study was to determine whether metformin, an agent used in the treatment of an obesity-related condition (type II diabetes), might have therapeutic potential for modifying the effects of obesity on airway smooth muscle (ASM) function. Metformin acts via activation of AMP-activated protein kinase (AMPK), a cellular sensor of energy status. In cultured murine ASM cells, metformin (0.2--2 mM) caused a dose-dependent inhibition of cell proliferation induced by PDGF (10^-8 M) and serotonin (10^-4 M). Another AMPK activator, 5-aminoimidazole-4-carboxamide-1-ß-D-riboruranoside (AICAR), also inhibited PDGF-induced proliferation. Furthermore, cells More >