This study addressed the following questions: 1) Does cyclic tensile strain induce protein expression patterns consistent with myxomatous degeneration in mitral valves? 2) Does cyclic strain induce local serotonin synthesis in mitral valves? 3) Are cyclic strain-induced myxomatous protein expression patterns in mitral valves dependent on local serotonin? Cultured sheep mitral valve leaflets wer...

A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 microm beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the "knife edge" approach. Measurem...

Anew set-up is proposed to perform high strain rate tension experiments on sheet metal using a compression Hopkinson bar system on the input side.With the help of a custommade load inversion device, the compression loading pulse is converted into tensile loading of the specimen boundary. A tensile output bar is used to measure the tensile force acting on the specimen boundaries. A high speed ca...

Seeking light and transparent bridge designs, engineers and architects have found an efficient and artistic way to fulfill their requirements: steel tubular bridges. Like any other welded structure, the joints of this kind of bridge suffer from high tensile weld residual stresses. Combined with high stress concentrations, tensile residual stress is a relevant factor in fatigue crack development...

Arapaima gigas, a fresh water fish found in the Amazon Basin, resist predation by piranhas through the strength and toughness of their scales, which act as natural dermal armour. Arapaima scales consist of a hard, mineralized outer shell surrounding a more ductile core. This core region is composed of aligned mineralized collagen fibrils arranged in distinct lamellae. Here we show how the Bouli...

This study evaluates two mechanical properties, tensile strength and tear strength, of maxillofacial materials reinforced with functional polyhedral silsesquioxane (POSS) nanoparticles at 0.0, 0.5, 1.0, 2.0, and 5.0% (mass/mass) loading. Adding POSS was found to significantly affect the overall tensile strength and extensibility of the maxillofacial material. Significant differences were found ...

Free-standing metallic thin films are increasingly used as structural components in MEMS. In commercial devices, long-term reliability is essential, which requires determining time-dependent mechanical properties of these films. The uniaxial tensile test is a preferred method due to uncomplicated determination of the stress and strain state. However, at the MEMS-scale this method is not straigh...

This article describes design concept and material characteristics of a new ductile fiber reinforced cementitious composite referred to as ECC (Engineered Cementitious Composite). This particular ECC contains Polyvinyl Alcohol fiber and exhibits remarkably ductile tensile property with over 1% of tensile strain capacity. The high tensile strain performance of the ECC was found successfully util...

The present paper discusses the results of an investigation into the effects of test rate and the mode of loading on the fracture energy, Gc, of adhesively-bonded fibre-composite joints. Various carbon-fibre reinforced-polymer (CFRP) matrix composite substrates have been bonded using two different types of automotive structural epoxy-adhesives. They have been tested via loading the bonded joint...

The effect of static and cyclic loading conditions on the stress corrosion cracking of unidirectional glass reinforced polymer (GRP) rods used in composite high voltage insulator has been investigated. A series of stress corrosion experiments have been performed on unidirectional E-glass/modified polyester composite rods. The rods have been subjected to mechanical tensile static and cyclic stre...