axial vibration effect of shell particles on dynamic stability of a cantilevered cylindrical shell under an axial follower force was addressed. in spite of free-ended shells, the reduced axial force under this effect cannot be derived analytically. instead, an approximate method was proposed based on the fact that the static (and harmonic) axial deformation under an axial load in a free-ended b...

molecular dynamics simulation has been performed to analyze the effect of the presence of gold nanoparticle on dynamics of kob-anderson binary lennard-jones (blj) mixture upon supercooling within the framework of the mode coupling theory of the dynamic glass transition. the presence of gold nanoparticle has a direct effect on the liquid structure and causes the peaks of the radial distribution ...

background & aim: despite the advantages of natural childbirth and complications associated with cesarean section, rate of cesarean delivery has increased dramatically in recent years. therefore, appropriate training is essential to reducing this trend. this study aimed to evaluate the effects of training about the benefits of natural childbirth on the attitude and intention to select the mode ...

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...