The influence of a strong surface potential on the critical depinning of an elastic system driven in a random medium is considered. If the surface potential prevents depinning completely the curvature C of the displacement profile exhibits at zero temperature a pronounced rhombic hysteresis curve of width 2f(c) with the bulk depinning threshold f(c). The hysteresis disappears at nonzero tempera...

Simulating the wheel/rail contact of a train is traditionally conducted using small-scale twin-disc testing. Here an emerging alternative method, “high pressure torsion” (HPT) test introduced. This has advantages over testing as only one cycle used and it easier to control third body layers during Shear stress data generated useful on its own, but can also be parameterise analytical prediction ...

BACKGROUND Tissue expansion is a concept based on the skin's natural ability to stretch in response to an underlying force. OBJECTIVE The purpose of this article is to review the histological and physiological changes that occur within the soft tissue and underlying structures during tissue expansion. METHODS An extensive search of the literature reviewing these changes is summarized herein...

During a micromanipulation, it is important to have the same performances whatever the manipulated object is. We present in this paper the control of the force applied to flexible and rigid micro-objects by a piezoelectric cantilever. First, the voltage-force transfer function is modeled. The hysteresis and creep phenomena are taken into account. The reliance of the model on the characteristics...

In the Present study, attempt will be made to propose a new method for prediction of long-term essential creep of concrete utilizing some short-term creep tests under high temperature. To do so, regarding the similarities between essential creep of concrete and creep in viscoelastic materials, the time–temperature equivalence relation in viscoelastic materials is evaluated for concrete. This re...

Bolted joints are used widely in mechanical design and represent a weak link in a system where loss of joint clamping force can lead to degraded product performance or human injury. To meet current market demands, designers require reliable material data and analysis tools for their industry specific materials. The viscoelastic response of bolted aluminum joints used in the small die-cast engin...

While the fundamental limit on the resolution achieved in an atomic force microscope (AFM) is clearly related to the tip radius, the fact that the tip can creep and/or wear during an experiment is often ignored. This is mainly due to the difficulty in characterizing the tip, and in particular a lack of reliable methods that can achieve this in situ. Here, we provide an in situ method to charact...

When sufficient force is applied to a glassy polymer, it begins to deform through movement of the polymer chains. We used an optical photobleaching technique to quantitatively measure changes in molecular mobility during the active deformation of a polymer glass [poly(methyl methacrylate)]. Segmental mobility increases by up to a factor of 1000 during uniaxial tensile creep. Although the Eyring...

In atomic force microscopy (AFM), the dynamics and nonlinearities of its nanopositioning stage are major sources of image distortion, especially when imaging at high scanning speed. This chapter discusses the design and experimental implementation of an observer-based model predictive control (OMPC) scheme which aims to compensate for the effects of creep, hysteresis, cross-coupling, and vibrat...

A method using atomic force microscope (AFM) optical levers and a reference nanopositioning stage has been developed to characterize piezoscanner hysteresis and creep. The piezoscanner is fixed on a closed-loop nanopositioning stage, both of which have the same arrangement on each axis of the three spatial directions inside the AFM-based nanomanipulation system. In order to achieve characteriza...