This paper investigates the variations of reflection spectra of embedded fiber Bragg gratings sensor in composites brought by the complicated deformation conditions, namely, strain induced grating apodization and spectrum split. The geometric change of the fiber is considered together with the strain-induced permittivity perturbations in the fiber gratings. Due to strain induced birefringence c...

A framework for development of constitutive models based on semi-micromechanical aspects of plasticity is proposed. The resulting of this model for material employed friction type failure criterion, sub-loading surface, and associated flow rule. This model is capable of predicting effects of the rotation of principal stress/strain axes and consequent plastic flow, induced anisotropy of strength...

in this paper, the mean value of strain energy density criterion has been used to predict the critical fracture load in specimens with u-shaped notch under bending loads. an equation for calculation of averaged strain energy density in this zone has been presented. bending loads under mode i have been considered. two cases have been studied: 1) the control volume only includes the semicircular ...

as it has proven the increase of mechanical strain could resulted to increase of bnp (protein brain natriuretic peptide) in blood stream of implanted patient pacemakers. we measured the bnp concentration in blood due to different mode and lead implantation location of pacemaker in the time period of three month. the aim of study was the investigation of change trend of bnp level after pacemaker...

We demonstrate a high-power passively mode-locked Nd:YVO (4) laser that uses a saturable Bragg reflector (SBR) with strain relaxation. 23.5 W of average power with ~21.5-ps cw mode-locked pulse trains was generated at a 50-W pump power. Experimental results show that appropriate strain relaxation in the SBR makes the mode-locking operation less sensitive to temperature variation.

The spectral, interferometric, and polarization properties of mode-coupling fiber gratings under strain are described. The grating is formed by photosensitivity that uses modal interference in the two-mode fiber. Theoretical and experimental results show the possibilities of using the fiber grating for optical switches, tunable filters, interferometric sensors, and polarizers.

In this paper a variationally consistent trigonometric shear deformation theory is presented for the free vibration of thick isotropic square and rectangular plate. In this displacement based theory, the in-plane displacement field uses sinusoidal function in terms of thickness coordinate to include the shear deformation effect. The cosine function in terms of thickness coordinate is used in tr...

BACKGROUND The failure mechanism of the knee ligament (bone-ligament-bone complex) at different strain rates is an important subject in the biomechanics of the knee. This study reviews and summarizes the literature describing ligament injury as a function of stain rate, which has been published during the last 30 years. METHODS Three modes of injury are presented as a function of strain rate,...