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 >

M. Timmel¹, M. Kaliske¹, S. Kolling², R. Mueller³

CMC-Computers, Materials & Continua, Vol.5, No.3, pp. 161-172, 2007, DOI:10.3970/cmc.2007.005.161

Abstract A damage approach based on a material model with microstructural evolution is presented. In contrast to phenomenological constitutive laws, the material response is given by mechanisms at the microscale. At first, a micromechanical substructure is chosen, which represents the overall material behaviour. Then the system is described using a micromechanical model. A geometrical modification of the microstructure is allowed to minimize the total energy. Consequently, the global stiffness is reduced. In this context, thermodynamical considerations are based on configurational forces. With the help of the discussed approach, void growth phenomena of materials, which lead to More >

K.Y. Volokh¹

Molecular & Cellular Biomechanics, Vol.3, No.1, pp. 35-42, 2006, DOI:10.3970/mcb.2006.003.035

Abstract It is common practice in the arterial wall modeling to assume material incompressibility. This assumption is driven by the observation of the global volume preservation of the artery specimens in some mechanical loading experiments. The global volume preservation, however, does not necessarily imply the local volume preservation -- incompressibility. In this work, we suggest to use the arterial ring- cutting experiments for the assessment of the local incompressibility assumption. The idea is to track the local stretches of the marked segments of the arterial ring after the stress-relieving cut. In the particular case of the rabbit… More >

A. P. S. Selvadurai¹, Q. Yu²

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.1, pp. 85-110, 2005, DOI:10.3970/cmes.2005.009.085

Abstract A characteristic feature of a polymeric material such as PVC is its hyperelasticity or the ability to experience large strains prior to failure. The exposure of PVC to chemicals such as acetone and ethanol results in embrittlement or the loss of the hyperelasticity property. In this paper, we examine the mechanical behaviour of a PVC membrane that has been exposed to ethanol. Due to leaching of the plasticizer, the constitutive response of the PVC changes from a hyperelastic material to a hardened material that displays dominant yield behaviour and particularly one that is capable of… More >