Consider a steel-rust-concrete composite consisting of a circular cylindrical concrete cover and a coaxial uniformly corroding steel reinforcement. Prediction of the amount of rust penetrated into the microcracks of concrete cover from a set of data measured at the surface of the concrete is of particular interest. The steel is assumed to be linear isotropic and rust follows a power law stress–strain relation. For the concrete, anisotropic behavior and post-cracking softening model is emplo...
The capabilities of the proposed nonlocal beam models in the companion paper in capturing the critical velocity of a moving nanoparticle as well as the dynamic response of double-walled carbon nanotubes (DWCNTs) under a moving nanoparticle are scrutinized in some detail. The role of the small-scale effect parameter, slenderness of DWCNTs and velocity of the moving nanoparticle on dynamic deflections and nonlocal bending moments of the innermost and outermost tubes as well as their maximum val...
The current work suggests mathematical models for the vibration of double-walled carbon nanotubes (DWCNTs) subjected to a moving nanoparticle by using nonlocal classical and shear deformable beam theories. The van der Waals interaction forces between atoms of the innermost and outermost tubes are modeled by an elastic layer. The equations of motion are derived for the nonlocal double body Euler–Bernoulli, Timoshenko and higher-order beams connected by a flexible layer under excitation of a ...
The free longitudinal vibration of tapered nanowires is investigated in the context of nonlocal continuum theory. The problem is studied for the nanowires with linearly varied radii under fixed–fixed and fixed–free boundary conditions. In order to assess the problem in a more general form, a perturbation technique is proposed based on the Fredholm alternative theorem. The natural frequencies, corresponding mode shapes, and phase velocities of the tapered nanowires are derived analytically...
A single-walled nanotube structure embedded in an elastic matrix is simulated by the nonlocal Euler–Bernoulli, Timoshenko, and higher order beams. The beams are assumed to be elastically supported and attached to continuous lateral and rotational springs to take into account the effects of the surrounding matrix. The discrete equations of motion associated with free transverse vibration of each model are established in the context of the nonlocal continuum mechanics of Eringen using Hamilto...
Dynamic response of multispan viscoelastic thin beams subjected to a moving mass is studied by an efficient numerical method in some detail. To this end, the unknown parameters of the problem are discretized in spatial domain using generalized moving least square method (GMLSM) and then, discrete equations of motion based on Lagrange’s equation are obtained. Maximum deflection and bending moments are considered as the important design parameters. The design parameter spectra in terms of mas...
One of the most crucial factors affecting the service life of reinforced concrete (RC) structures attacked by aggressive ions is reinforcement corrosion. As the steel corrosion progresses, crack propagation in concrete medium endangers the serviceability and the strength of RC structural members. In this study, a nonlinear mathematical model for determining the displacement and stress fields in RC structures subjected to reinforcement corrosion is introduced. For corrosion products, a nonline...
Dynamic analysis of nanotube structures under excitation of a moving nanoparticle is carried out using nonlocal continuum theory of Eringen. To this end, the nanotube structure is modeled by an equivalent continuum structure (ECS) according to the nonlocal Euler–Bernoulli, Timoshenko and higher order beam theories. The nondimensional equations of motion of the nonlocal beams acted upon by a moving nanoparticle are then established. Analytical solutions of the problem are presented for simpl...
Single-walled carbon nanotubes (SWCNTs) can be promising delivery nanodevices for a diverse range of applications, however, little is known about their dynamical interactions with moving nanoscale particles. In this paper, dynamic response of a SWCNT subjected to a moving nanoparticle is examined in the framework of the nonlocal continuum theory of Eringen. The inertial effects of the moving nanoparticle and the existing friction between the nanoparticle surface and the inner surface of the S...
In this paper, a comprehensive assessment of design parameters for various beam theories subjected to a moving mass is investigated under different boundary conditions. The design parameters are adopted as the maximum dynamic deflection and bending moment of the beam. To this end, discrete equations of motion for classical Euler–Bernoulli, Timoshenko and higher-order beams under a moving mass are derived based on Hamilton's principle. The reproducing kernel particle method (RKPM) and extend...
ABSTRACT The study was focused on Communication Equipment and the Student’s Performance Among Fourth Year Students of the Bachelor of Science in Office Administration of Laguna State Polytechnic University San Pablo City Campus to provide and gather as much informative evaluation descriptive method was used. This method includes using questionnaires. Specially sought to answer the following question: what is the profile of the respondents regarding age, gender and civil status of 4th year B...
This study covers the evaluation of the synergistic effect of Datura stramonium leaves extract-Zn2+ in the corrosion inhibition of mild steel in well water. Varying effects of different concentrations of the extract and 5ppm of Zn2+ on the corrosion inhibition of the mild steel specimen will be determined in order to ascertain the synergistic effect that exists between the leaf extract and Zn2+
ABSTRACT For the past few years, the oil and gas industry has faced several economic, geographic and technical challenges largely due to decline in crude oil prices and market volatility. In the quest to address some of these challenges to accelerate production and subsequently maximize ultimate recovery, operators are limited to remote hydraulic and electro-hydraulic monitoring and control of safety valves providing the means of obtaining downhole production data which demands peri...
The availability and stability of electrical energy is necessary for domestic and industrial use. But unfortunately the monopoly which the Power holding company of Nigeria (PHCN) enjoys in this country is not in favor of the electricity users, because the supply is never constant and damages occur due to inconsistency of this supply is very enormous. However, millions of naira’s are lost every day in the commercial and industrial sectors, and even at the same time a lot of Lives are wasted ...
ABSTRACT The primary objective of this study is to identify the most appropriate herbal plants for the removal of contaminants from water and also to develop a water treatment kit at an affordable cost for the society. Moringa Oleifera was chosen for this study, the effectiveness of these herbs in the removal of fluoride from water shows that Moringa Oleifera is economically viable, physically feasible and socially acceptable. Moringa Oleifera seed is an organic material that has proven eff...