Thanks to extensive observations of strain localization upon startup or after stepwise shear, a conceptual framework for nonlinear rheology of entangled polymers appears to have emerged that has led to discovery of many new phenomena, which were not previously predicted by the standard tube model. On the other hand, the published theoretical and experimental attempts to test the limits of the t...

In this study, nonlocal nonlinear instability and the vibration of a double carbon nanotube (CNT) system have been investigated. The Visco-Pasternak model is used to simulate the elastic medium between nanotubes, on which the effect of the spring, shear and damping of the elastic medium is considered. Both of the CNTs convey a viscose fluid and a uniform longitudinal magnetic field is applied t...

In this paper, the dynamic response of resonating nano-beams is investigated using a strain gradient elasticity theory. A nonlinear model is obtained based on the Galerkin decomposition method to find the dynamic response of the investigated beam around its statically deflected position. The mid-plane stretching, axial residual stress and nonlinear interaction due to the electrostatic force on ...

This paper suggests an optimization-based methodology for the design of minimum weight structures with kinematic nonlinear behavior. Attention is focused on three-dimensional reticulated structures idealized with beam elements under proportional static loadings. The algorithm used for optimization is based on a classical optimality criterion approach using an active-set strategy for extreme lim...

ten field isolates of mycoplasma gallisepticum (mg) from different geographical areas of iran were analyzed by random amplification of polymorphic dna (rapd). rapd analysis produced reproducible banding patterns on the basis of which various distinct amplification patterns could be detected. mg isolates compared with reference strains (s6 and mg ss) and vaccine strain (ts-11) and demonstrated d...

The optical second-harmonic generation from a thin crystalline film on a substrate is theoretically investigated for both s and p polarized incident light. The contributions of lattice misfit strain as well as of misfit dislocation strain to the second-order nonlinear optical susceptibility are described using a nonlinear photoelastic tensor and can be separated by a polarization analysis of th...

Dark-field microscopy is a background-free imaging method that provides high sensitivity and a large signal-to-noise ratio. It finds application in nanoscale detection, biophysics and biosensing, particle tracking, single molecule spectroscopy, X-ray imaging, and failure analysis of materials. In dark-field microscopy, the unscattered light path is typically excluded from the angular range of s...

The main mechanism of the cellular pattern which forms at the surface of a thin layer of a cohesive granular material submitted to in-plane stretching has been identified as the "strain softening" arising from the features of grain-grain interactions. We perform measurements of the strain field associated with such structures by using a correlation image technique and additionally characterize ...

56 ground motions of the bedrock and surface are selected from 28 stiff sites ( site class I and site classⅡ) of the KiK-net station．The peak acceleration, response spectra and shear strain of actual hard sites are calculated by using SHAKE2000 and LSSRLI-1. The similarities and differences between SHAKE2000 and LSSRLI-1 and their differences from measured records are analyzed. It provides a ba...

A constitutive model based on two–dimensional unstructured Galerkin finite volume method (GFVM) is introduced and applied for analyzing nonlinear behavior of cracked concrete structures in equilibrium condition. The developed iterative solver treats concrete as an orthotropic nonlinear material and considers the softening and hardening behavior of concrete under compression and tension by using...