this paper presents the thermal vibration analysis of double-layer graphene sheet embedded in polymer elastic medium, using the plate theory and nonlocal continuum mechanics for small scale effects. the graphene is modeled based on continuum plate theory and the axial stress caused by the thermal effects is also considered. nonlocal governing equations of motion for this double-layer graphene s...

the problem of relative motion control for spacecraft formation flying in eccentric orbits is considered in this paper. due to the presence of nonlinear dynamics and external disturbances, a robust fuzzy sliding mode controller is developed. the slopes of sliding surfaces of the conventional sliding mode controller are tuned according to error states using a fuzzy logic and reach the pre-define...

sudden fracture is one of the major failure modes in brittle materials. plexiglass (polymethyl methacrylate) is a well known brittle polymer, widely used in various industries. many types of notches, particularly v-shaped notches, are sometimes used in the components made of plexiglass. these notches can dramatically decrease the load bearing capacity of components due to the concentration of s...

In inclined U-notches, the mixed mode (I + II) loading occurs and the mode ratio can be increased by varying the notch angle. In this paper, the effect of the inclined U-notch geometry, i.e. the notch depth, the notch angle, the notch root radius, and the position of the notch with respect to supports, on the mode ratio (KII/KI) have been studied. Three-point bending and plane strain condition ...

This work proposes a neural-fuzzy sliding mode control scheme for a hydro-turbine speed governor system. Considering the assumption of elastic water hammer, a nonlinear mode of the hydro-turbine governor system is established. By linearizing this mode, a sliding mode controller is designed. The linearized mode is subject to uncertainties. The uncertainties are generated in the process of linear...

Natural and artificial materials including rocks and cement-based materials such as concrete and cement mortar are affected both physically and chemically by various natural factors known as weathering factors. The freeze-thaw process, as a weathering factor, considerably affects the properties of rocks and concrete. Therefore, the effect of the freeze-thaw process on the physical and mechanica...

this paper addresses the design of an observer-based fault diagnosis scheme, which is applied to some of the sensors and actuators of a wind turbine benchmark model. the methodology is based on a modified sliding mode observer (smo) that allows accurate reconstruction of multiple sensor or actuator faults occurring simultaneously. the faults are reconstructed using the equivalent output error i...

introduction: the risk of morbidity and mortality increases in neonates admitted to the neonatal intensive care units (nicus). various factors contribute to the prognosis of these newborns. in the current study, we aimed to investigate the role of mode of delivery on short-term neonatal outcomes. methods: this retrospective study was conducted on 215 neonates admitted to the nicu of shohada-e-t...

in this paper, we discuss the dynamical properties of a chemical reactor model including lyapunov exponents, bifurcation, stability of equilibrium and chaotic attractors as well as necessary conditions for this system to generate chaos. we study the synchronization of chemical reactors model via sliding mode control scheme. the stability of proposed method is proved by barbalate’s lemma. numeri...