Deformable joint contact models can be used to estimate loading conditions for cartilage-cartilage, implant-implant, human-orthotic, and foot-ground interactions. However, contact evaluations are often so expensive computationally that they can be prohibitive for simulations or optimizations requiring thousands or even millions of contact evaluations. To overcome this limitation, we developed a...

We provide a brief overview of the Discrete Element Method (DEM) for modeling large frictional contact problems in granular flow dynamics and quasi-static geomechanics applications. In terms of contact, DEM can be divided into two approaches: the Constraint Method (CM) or rigid-body approach, and the Penalty Method (PM) or soft-body approach. We give a detailed presentation of a DEM-PM contact ...

Parameterised finite element models of the human hip have the potential to allow controlled analysis of the effect of individual geometric features on the contact mechanics of the joint. However, the challenge lies in defining a set of parameters which sufficiently capture the joint geometry in order to distinguish between individuals. In this study, a simple set of parameters to describe the g...

Existing beam contact formulations can be categorized in point-to-point contact models that consider a discrete contact force at the closest point of the beams, and line-to-line contact models that assume distributed contact forces. In this work, it will be shown that line contact formulations applied to slender beams provide accurate and robust mechanical models in the range of small contact a...

A variety of analytical and computational models have been proposed to answer the question of why some protein structures are more ‘‘designable’’ ~i.e., have more sequences folding into them! than others. One class of analytical and statistical-mechanical models has approached the designability problem from a thermodynamic viewpoint. These models highlighted specific structural features importa...

Validation is critical if clinicians are to use musculoskeletal models to optimize treatment of individual patients with a variety of musculoskeletal disorders. This paper provides an update on the annual Grand Challenge Competition to Predict in Vivo Knee Loads, a unique opportunity for direct validation of knee contact forces and indirect validation of knee muscle forces predicted by musculos...

In the present study, silica aerogel- egg shell was synthesized for dye removal of colored wastewater. The nano composite structure was characterized by Fourier transform infrared spectra FTIR and scanning electron microscope SEM.The ability of nano composite absorption was assessed for removal basic violet 16BV16 dye from aqueous solutions and was compared with two other adsorbents such as egg...

Opportunistic networking, where node mobility is utilized to achieve message delivery, has become an important class of mobile ad hoc networking. A critical component of performance analysis for opportunistic networking is a basic understanding of contact and inter-contact times for commonly studied mobility models. In this paper we give original results nodal contact-times and analytically sho...

Dynamic interaction between two bodies, where one is significantly more flexible than the other, is common (e.g. rotor-casing contact). This paper presents a linear model for simulating contact between rigid and flexible bodies. The motion between contacts is predicted by modal superposition, using separate models for the two components. During contact, the models are coupled via a linear conta...

Spreading phenomena are ubiquitous in nature and society. For example, disease and information spread over underlying social and information networks. It is well known that there is no threshold for spreading models on scale-free networks; this suggests that spread can occur on such networks, regardless of how low the contact rate may be. In this paper, I consider six models with different cont...