INTRODUCTION: The current study compared in-vitro tibiofemoral axial rotational constraint between 2 posterior stabilized mobile-bearing knee prosthesis and their fixed-bearing counterparts. It was demonstrated that both mobile-bearing knees induced significantly less constraint torque compared to their fixed-bearing counterparts. Highly-constrained design of the fixed-bearing knees substantial...

In this paper, the plastic limit load of cylindrical shells with opening subject to combined bending moment and axial force are found by finite element method using ANSYS suite of program. The effect of various parameters such as the geometrical ratios of shell and the shape, size, axial and angular position of the opening on the limit load of cylindrical shells under various loading conditions...

Rotating fan shaft system was investigated experimentally and theoretically to study its dynamic performance. The type of oil used for the bearing taken in consideration during experimental program .Three types were used, SAE 40, 50 degraded oil. During experiments, blades stagger angle changed through angles (20˚, 30˚, 40˚, 50˚). rotational speed also range (0-3000 rpm). All these parameters h...

The energy absorbing capability is one of the most important aspects of crushing behavior of a structure subjected to axial impact. In this paper, a simple practical method is introduced to enhance the crushing behavior of this kind of structure. The axial impact of metallic energy absorbing thin-walled tubes with special shaped cross-section is simulated using LS-DYNA software. The effect of c...

This study aimed to investigate the effects of stiffeners on buckling of thin cylindrical shells under uniform axial compression. To this end, more than 300 finite element models of stiffened cylindrical shells were prepared. The variables considered are shell thickness, number, dimension and the location of the vertical and horizontal stiffeners as well as circular symmetrical imperfections. R...

We show that, at any Fresnel number, a suitable one-dimensional Fourier transform relates the complex-amplitude distribution along the optical axis with the zero-order circular harmonic of the amplitude transmittance of a two-dimensional diffracting screen. First, our general result is applied to recognize that any rationally nonsymmetric screen generates an axial-irradiance distribution that e...

INTRODUCTION The ordinary hydrodynamic bearings have been replaced by the hydrostatic bearings in the application of machine tools in recent years. For the hydrodynamic bearings, the journal and the bearing surface are separated by the sliding action with a wedge pressure-generating mechanism to develop a pressure within the bearing. It has advantages of simple structure and cheap cost. However...

Hydrostatic bearings are superior in terms of their friction and load carrying characteristics when compared to contact based bearings, but non-usable applications with non-constant curvature counter surfaces. A possible solution this limitation is the introduction deformable hydrostatic components that cope these required deformations. To reduce deformation a single bearing pad, multiple pads ...

This study investigates geometrical non-linear analysis of composite circular cylindrical shells under external pressure over part of their surfaces and also shells subjected to combined axial compression and triangular external pressure. Donnell non-linear shell theory along with first order shear deformation theory (FOSD) are adopted in the analysis. In the case of combined axial compression ...