INTRODUCTION The urinary bladder is a smooth muscle organ whose main functions are to store urine and to void when necessary. Since the most important aspect of the storage function of the bladder is to maintain low intravesical pressure in order to protect the upper urinary tract from backflow of urine, the compliance of the bladder wall is one of the key functional parameters to assess the he...

Mounting evidence suggests that the normal biomechanical state of arteries may include a nearly equibiaxial intramural stress and that arteries tend to undergo rapid and dramatic remodeling when perturbed from this normal state. Technical developments since the early 1980s have enabled in vitro (acute) and ex vivo (chronic culture) study of isolated, perfused microvessels, and it is clear that ...

A new acellular, natural, biodegradable matrix has been discovered in the cholecyst-derived extracellular matrix (CEM). This matrix is rich in collagen and contains several other macromolecules useful in tissue remodeling. In this study, the principal material axes, collagen fiber orientations, and biaxial mechanical properties in a physiological loading regime were characterized. Fiber directi...

A mesoscopic, extended Doi theory for  ows of nematic liquid crystals (LCs) has been successfully applied by Rey to study extensional  ow-induced, homogeneous phase transitions both for rod-like and disc-like molecular geometry. Rey analysed the two order parameters (eigenvalues) of the orientation tensor. Recently the authors generalized the  ow-phase diagram (nematic concentration vs.  ow...

One method of fabricating implantable biomaterials is to utilize biologically derived, chemically modified tissues to form constructs that are both biocompatible and remodelable. Rigorous mechanical characterization is a necessary component in material evaluation to ensure that the constructs will withstand in vivo loading. In this study we performed an in-depth biaxial mechanical and quantitat...

We study optical, structural, and surface anchoring properties of thermotropic nematic bent-core material A131. The focus is on the features associated with orientational order as the material has been reported to exhibit not only the usual uniaxial nematic but also the biaxial nematic phase. We demonstrate that A131 experiences a surface anchoring transition from a perpendicular to tilted alig...

Sun, Jianzhuo. M.S.A.A., Purdue University, May 2014. Biaxial Shear/Tension Failure Criteria of Spectra single fibers. Major Professor: Weinong Chen. An experimental study was conducted to develop the biaxial failure surface criteria of single Spectra 130d and 100d filaments in a torsion-tension environment. The crosssectional profiles of single Spectra fibers were investigated using scanning e...

To date, there are no constitutive models for either the natural or bioprosthetic aortic valve (AV), in part due to experimental complications related to the AV's small size and heterogeneous fibrous structure. In this study, we developed specialized biaxial testing techniques for the AV cusp, including a method to determine the local structure-strain relationship to assess the effects of bound...

Cylindrical shells under uniaxial compression and spherical shells under equi-biaxial compression display the most extreme buckling sensitivity to imperfections. In engineering practice, the reduction of load carrying capacity due to imperfections is usually addressed by use of a knockdown factor to lower the critical buckling stress estimated or computed without accounting for imperfections. F...