A stable dual-wavelength thulium-doped fiber laser operating at 1.9 μm using a short length of photonic crystal fiber (PCF) has been proposed and demonstrated. The photonics crystal fiber was 10 cm in length and effectively acted as a Mach-Zehnder interferometry element with a free spectral range of 0.2 nm. This dual-wavelength thulium-doped fiber laser operated steadily at room temperature wit...

Biomechanical analyses on lumbar spine under compressive load and flexion torque were performed using a nonlinear three-dimensional finite element method to evaluate the stability of artificial disc replacement. We prepared a validated intact lumbar L4-L5 motion segment and artificial disc inserted motion segment by replacing intact disc with the artificial disc which is being developed. Effect...

the three-phase-lag model and green–naghdi theory without energy dissipation are employed to study the deformation of a two-temperature fiber-reinforced medium with an internal heat source that is moving with a constant speed under a hydrostatic initial stress and the gravity field.  the modulus of the elasticity is given as a linear function of the reference temperature. the exact expressions ...

Agricultural waste fibers have been found to be suitable as reinforcement in cement-based composites, but studies on oil palm fiber as reinforcement in gypsum-cement wall panels are scarce. A mixture of two equal weights of gypsum and cement, with water-binder ratios of 0.45 and 0.55 were prepared. In each mix a varying percentage of fiber contents of 2%, 3% and 4% by weight of the binders were...

Computational implementation of physical and physiologically realistic constitutive models is critical for numerical simulation of soft biological tissues in a variety of biomedical applications. It is well established that the highly nonlinear and anisotropic mechanical behaviors of soft tissues are an emergent behavior of the underlying tissue microstructure. In the present study, we have imp...

In this paper, we study the efficiency of applying the numerical simulation of a moving interface to the problem of defining fiber placement trajectories for composite structures. This new approach, which is based on an adaptation of the Fast Marching method, presents two advantages. Firstly, it simulates accurately the mechanism of an Automated Fiber Placement (AFP) machine by producing equidi...

This paper presents a mathematical model of the sensitive element refractometric fiber-optic sensor principle operation which is based on phenomenon surface plasmon resonance. The sensing design sequential connection multimode fiber (MMF), single-mode (SMF), and forming an MMF-SMF-MMF structure. SMF site coated with thin film gold. To element, approach used in calculating classical Kretschmann ...

The results obtained from nonlinear fiber element analyses for concrete filled tubes (CFT) are discussed. The studies were aimed at assessing primarily the overall behavior and stability effects on these structural elements as a prelude to a large full-scale testing program. The study focuses on ultimate strength analyses for CFT composite columns with different stress-strain models for both co...

An experimental approach is developed and utilized to characterize the fiber-matrix interfacial debonding mechanism its effect on matrix cracking in unidirectional (UD) fiber composites. Local deformation response at interface first studied by analyzing strain fields vicinity of macro fibers single-fiber samples. A practical for identification normal cohesive behavior presented implemented a fi...

Damage constitutive models based on micromechanical formulation and a combination of micromechanical and macromechanical damage criterions are presented to predict progressive damage in aligned and random fiber-reinforced composites. Progressive interfacial fiber debonding models are considered in accordance with a statistical function to describe the varying probability of fiber debonding. Bas...