It is well known that a spherically symmetric constant density static star, modeled as a perfect fluid, possesses a bound on its mass m by its radial size R given by 2m/R ≤ 8/9 and that this bound continues to hold when the energy density decreases monotonically. The existence of such a bound is intriguing because it occurs well before the appearance of an apparent horizon at m = R/2. However, ...

The aim of the study was to find the optimum combination of materials and thicknesses to provide a tough, damage resistant multi-layer system with numerical methods to restore the damaged teeth. Extended Finite Element Method (XFEM) was used to assess the critical loads for the onset of damage modes such as radial cracks and plastic deformation in dental prostheses, which consist of a brittle o...

Residual stresses are present in a number of soft tissues. In the case of arterial walls they are supposed to be responsible for a smoothed circumferential stress gradient in radial direction. In the recent past, several publications dealt with residual stresses based on a multiplicative split of the deformation gradient using a cylindrical coordinate system, cf. for example [1], [2] and [3] an...

The conventional elastic analysis of thick walled cylinders to final radial & hoop stresses is applicable for the internal pressures up to yield strength of material. The stress is directly proportional to strain up to yield point Beyond elastic point, particularly in thick walled cylinders. The operating pressures are reduced or the material properties are strengthened. There is no such existi...

BACKGROUND We determined whether any significant association exists between change in late systolic cardiac load with time, estimated by radial pressure waveform analysis, and development of cardiac hemodynamic stress in individuals with preserved cardiac function. METHODS Brachial-ankle pulse wave velocity, radial augmentation index (rAI), first peak of the radial pressure waveform (SP1), sy...

Electro-thermo-elastic stress analysis of piezoelectric polymeric thick-walled cylinder reinforced by boronnitride nanotubes (BNNTs) subjected to electro-thermo-mechanical fields is presented in this article. The electro-thermo-elastic properties of piezoelectric fiber reinforced composite (PEFRC) was studied by a modified XY micromechanical model capable of exhibiting full coupling relati...

A multi-scale model is proposed to investigate functionally graded (exponential or power-law grading in the radial direction) hollow cylinders (discs), with fibers, particles, or disc-shaped reinforcements, subjected to harmonic loading conditions. The stress analyses are performed by dividing the cylinders (discs) into several layers each with homogeneous properties, which are functionally gra...

Introduction and Background: Radial grabens at Tharsis record crustal extension due to the load [1−3]. However their development and significance beyond 2-D strain estimates are largely unknown. For example, early Viking-based strain models required two separate phases of Tharsis loading to produce the “inner” and “outer” radial grabens [4,5]. In contrast, recent MGS-based stress models for Tha...

Abstract—The present study focused on carrying out the creep analysis in an isotropic thick-walled composite cylindrical pressure vessel composed of aluminum matrix reinforced with silicon-carbide in particulate form. The creep behavior of the composite material has been described by the threshold stress based creep law. The values of stress exponent appearing in the creep law were selected as ...

BACKGROUND The purpose of this study is to propose a novel method for assessing dynamic elastance of the superficial arterial wall using the sinusoidal minute vibration method. METHODS A sinusoidal signal was used to drive a vibrator which induced a displacement of 0.15 mm with a frequency range between 40 and 85 Hz. The vibrator closely contacted with the wall of a superficial radial artery,...