F. Gao¹, D. Tang^2∗, Z. Guo³, Makoto Sakamoto⁴, T. Matsuzawa⁵

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.1, pp. 21-28, 2007, DOI:10.3970/icces.2007.001.021

Abstract Patients with aortic aneurysm, especially aortic arch aneurysm, are prone to aortic dissection. For investigation of the effects of aneurysm and wall stiffness on wall stress distribution, a nonaneurysm arch model as well as an aneurysm arch model was constructed. The fluid structure interaction was implemented in the arch model of aorta. The results show that the stresses are much higher at inflection points in the aneurysm model than in nonaneurysm model, and the stresses at media in stiffened wall are higher than in unstiffened wall. The high composite stress is located at inflection points More >

J.W. Choi¹, S.H. Yoo¹, J.B. Kim¹, E.J. Park¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.2, pp. 47-52, 2007, DOI:10.3970/icces.2007.002.047

Abstract A semi-analytical solution by beam theory and finite element solutions are obtained for normal deflection of a plate with a surface crack under tensile stress. The semi-analytical solution consists of the deflection of a beam and the half-space or full-space solution. Also finite element solutions are obtained and compared with these analytical solutions. These solutions can be used as reference data for non-destructive evaluation of a surface crack. More >

J. Li¹, Z.H. Xiang¹, M.D. Xue¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.1, pp. 7-12, 2007, DOI:10.3970/icces.2007.002.007

Abstract This paper presents a finite element scheme to analyze the buckling behavior of composite shells subjected to thermal and mechanical loads. Firstly, a kind of multi-layered composite shell element with relative degrees-of-freedom is adopted to model laminated composite shells. Then the corresponding temperature element is developed so that the mechanical analysis and the thermal analysis share a common mesh. Moreover, a new criterion of critical heat flux is proposed in stead of the traditional criterion of critical temperature. Finally, the advantage of the proposed scheme is illustrated by calculating the stable region of thermal-mechanical loads More >

E. Schnack¹, A. Dimitrov², F.-G. Buchholz³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.4, pp. 139-146, 2007, DOI:10.3970/icces.2007.001.139

Abstract In fracture mechanics, we have to discuss corner and edge singularities for two- and three-dimensional problems in isotropic and layered anisotropic continua. To say something about the behavior of crack propagation starting from corners and edges, we need the information about stress asymptotics in the vicinity of three-dimensional corner points. Thus, in this paper we can study two aspects: the interface crack in layered unisotropic materials with re-entrant corners and surface cracks for the homogeneous isotropic continua. To study the effect of geometrical singularities on the stress intensity factors, we have to define generalized stress… More >

Milazzo A.¹, aimo A.¹, Orl,o C.¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.2, pp. 69-74, 2007, DOI:10.3970/icces.2007.001.069

Abstract In this paper a Hierarchical approach for the analysis of advanced aerospace structures is presented. The proposed Global/Local model uses two kind of numerical methods for the different steps of analysis. In particular the first step of the Hierarchical procedure is performed by the Finite Element code Patran/NastranTM, while the local analysis is performed by using a Boundary Element code based on the multidomain anisotropic technique. The accuracy and the effectiveness of the model have been demonstrated analysing classical stress concentration problems. Then the procedure has been used to analyze more complex structure among which More >

C. Soutis¹, K. Diamanti¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.2, pp. 49-54, 2007, DOI:10.3970/icces.2007.001.049

Abstract A cost and time effective inspection strategy for in-service health monitoring of composites is demonstrated using the fundamental anti-symmetric A0 Lamb mode at frequencies of 15-20 kHz. In principle, this method involves analysis of the transmitted and/or reflected wave after interacting with the test-piece boundaries or discontinuities (defects). In the present work, the applicability of the technique to composite sandwich structures is explored. More >

Christopher J. Hunter^∗,†, Sophia Bianchi^*, Phil Cheng^‡, Ken Muldrew^∗,‡

Molecular & Cellular Biomechanics, Vol.4, No.4, pp. 227-238, 2007, DOI:10.3970/mcb.2007.004.227

Abstract The nucleus pulposi of many species contain residual cells from the embryonic notochord, which exhibit a very unusual appearance (large vacuoles occupying ~80% of the cell volume, surrounded by an actin cytoskeleton). While the vacuoles have been qualitatively described, their composition and function has remained elusive. Given that these cells are believed to generate and experience significant osmotic pressures in both the notochord and intervertebral disc, we hypothesized that the vacuoles may serve as osmoregulatory organelles. Using both experimental and theoretical means, we demonstrated that the vacuoles contain a low-osmolality solution, generated via ion pumps More >

Guanbin Song^∗,†,‡, Yang Ju^∗,†,§, Hitoshi Soyama^*, Toshiro Ohashi^¶, Masaaki Sato^¶

Molecular & Cellular Biomechanics, Vol.4, No.4, pp. 201-210, 2007, DOI:10.3970/mcb.2007.004.201

Abstract Mechanical stimulation is critical to both physiological and pathological states of living cells. Although a great deal of research has been done on biological and biochemical regulation of the behavior of bone marrow mesenchymal stem cells (MSCs), the influence of biomechanical factors on their behavior is still not fully documented. In this study, we investigated the modulation of mechanical stretch magnitude, frequency, and duration on the human marrow mesenchymal stem cells (hMSCs) proliferation by an in vitro model system using a mechanical stretch loading apparatus, and optimized the stretch regime for the proliferation of hMSCs.… 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 >

Donald F. Ward Jr.^*, William A. Williams^*, Nicole E. Schapiro^*, Samuel R. Christy^*, Genevieve L. Weber^*, Megan Salt, Robert F. Klees^*, Adele Boskey^†, George E. Plopper ^∗,‡

Molecular & Cellular Biomechanics, Vol.4, No.4, pp. 177-188, 2007, DOI:10.3970/mcb.2007.004.177

Abstract Focal adhesion kinase (FAK) is a key integrator of integrin-mediated signals from the extracellular matrix to the cytoskeleton and downstream signaling molecules. FAK is activated by phosphorylation at specific tyrosine residues, which then stimulate downstream signaling including the ERK1/2 pathway, leading to a variety of cellular responses. In this study, we examined the effects of FAK point mutations at tyrosine residues (Y397, Y925, Y861, and Y576/7) on osteogenic differentiation of human mesenchymal stem cells exposed to collagen I and cyclic tensile strain. Our results demonstrate that FAK signaling emanating from Y397, Y925, and to a More >