The effect of the ultrasonic surface rolling process (USRP) on the rotary bending fretting fatigue (FF) of Ti-6Al-4V alloy was investigated. The reason for the USRP's ability to improve the FF resistance of Ti-6Al-4V alloy was studied. The results revealed that the USRP induced a compressive residual stress field with a depth of 530 μm and a maximum residual stress of -930 MPa. Moreover, the su...

Residual stress development during processing of sol-gel derived ferroelectric thin films influences electromechanical properties and performance. The present work investigates the effects of stress on field-induced polarization switching in ferroelectric Pb~Zr0.52Ti0.48)O3 ~PZT! ~52/48! thin films. Film response is measured as a function of externally applied mechanical stress using a double-b...

Subjected to an electric field, a substrate-bonded polymer film develops a biaxial compressive stress parallel to the film. Once the electric field reaches a critical value, the initially flat surface of the polymer locally folds against itself to form a pattern of creases. We show that mechanical deformation of the polymer significantly affects the electro-creasing instability. Biaxially pre-s...

ABSTRACT This study aims to establish a methodology for determining the residual contact stress developed during fabrication of nonconductive adhesive (NCA) bonded flip-chip-on-flex (FCOF) microelectronics systems. The method is demonstrated for a selected non-conductive adhesive. Fabrication of an NCA bonded FCOF system requires a compressive force large enough to compensate for the inherent c...

This paper investigates the distribution of principal strain by micro mechanical measurement of concrete axial strain in Reinforced Cement Concrete (RCC) moderate deep beams across its width and depths for various span-to-depth ratios. A complete shear deformational behavior along with load-deflection response, crack patterns and modes of failure were studied experimentally. Twelve beams were t...

The residual stress field of HIPed Si3N4 rolling elements were studied. Two kinds of HIPed Si3N4 ball blanks self-finished at different nominal lapping loads ranging from 1.3kgf/ball to 10.87kgf/ball and four kinds of commercially finished 1⁄2′′ (12.7mm) HIPed Si3N4 balls before, during and after RCF tests were investigated. The experimental results showed that in the finishing process of HIPed...

The etiology of degenerative disease of the TMJ may involve fatigue produced by surface tractional forces and compressive stresses. This study tested the time-dependent effects of compressive loading and stress-field translation on TMJ disc-surface tractional forces and stresses. In laboratory experiments with 50 porcine discs, an acrylic indenter imposed 10 N static loads for 10 and 60 sec, fo...

According to the masonry standard the compressive strength is basically dependent on factors such as the mortar strength and the relative values of unit and mortar strength. However interlocking brick has none or less use of mortar. Therefore there is a need to investigate the behavior of masonry walls using interlocking bricks. In this study a series of tests have been conducted; physical prop...

In previous work (Peters and Poort, 1983), the stress distribution in axisymmetric models of restored teeth was analyzed by finite element analysis (FEA). To compare the tri-axial stress state at different sites, they calculated the Von Mises equivalent stress and used it as an indication for weak sites. However, the use of Von Mises' theory for material failure requires that the compressive an...