in this paper effects of fractured sleepers on rail track vibration under moving wheelset have been investigated. two parallel rails of the track have been modeled as euler-bernoulli beams on elastic points as rail pads. also sleepers have been modeled as visco-elastic euler-bernoulli beams. it is assumed that, some sleepers under the rail track have been fractured and modeled by two beams. the...

Hertz contact theory has been widely used for the determination of cell elasticity based on AFM indentation experiments. In light of the adhesive contact between AFM tip and cell, this study applied Johnson-Kendall-Roberts (JKR) model to fit the indentation force-displacement (F-D) curves reported previously. A MIN6 cell has been modeled as first a sphere and then a flattened cell with differen...

The forces acting on the substrate in intermittent-contact-mode (IC mode, tapping mode) atomic force microscopy are not accessible to a direct measurement. For an estimation of these forces, a simple analytical model is developed by considering only the shift of the cantilever resonance frequency caused by Hertzian (contact) forces. Based on the relationship between frequency shift and tip–samp...

Newton’s cradle for two balls with Hertzian interactions is considered as a hybrid system, and this makes it possible to derive return maps for the motion between collisions in an exact form despite the fact that the three halves interaction law cannot be solved in closed form. The return maps depend on a constant whose value can only be determined numerically, but solutions can be written down...

Lamb waves are currently used in many nondestructive testing applications to determine or monitor elastic properties of plate-like Structures using various excitation methods. The methods vary from point-like dry contact transducers and laser ultrasound techniques in hostile environments to wedge transducers for inspection of excitation of Lamb waves in 2-D geometry by surface immersed structur...

This work investigates plastic deformation around non-metallic inclusions in rolling contact fatigue applications. Subsurface stresses from Hertzian theory are applied form of far-field loading on an elasto-plastic micro-mechanical model isolated inclusion. Initial and cyclic micro-scale plasticity quantified, assuming linear kinematic hardening for the steel matrix elastic or perfectly behavio...

In chemical mechanical polishing (CMP), a rigid wafer is forced on a rough elastomeric polishing pad, while a slurry containing abrasive particles flows through the interface. One of the important factors that influence the material removal rate in CMP is the magnitude of contact force transmitted to the abrasive particles trapped at the contact interface. The total push-down force is distribut...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. We present a model for wave propagation in a monolayer of spheres on an elastic substrate. The model, which conside...