Decreases in patellofemoral pain have been demonstrated with bracing; however, the mechanisms of pain reduction remain unclear. Our purpose was to evaluate the hypothesis that patellofemoral bracing decreases peak pressure on the retropatellar surface through an increase in patellofemoral contact area. Nine cadaveric knees were tested during simulated free-speed walking with no brace, a knee sl...

I have developed a theory of contact mechanics between randomly rough surfaces. The solids are assumed to deform elastically when the stress sigma is below the yield stress sigma(Y), and plastically when sigma reaches sigma(Y). I study the dependence of the (apparent) area of contact on the magnification. I show that in most cases the area of real contact A is proportional to the load. If the r...

In part I of this work, we presented a theory for adhesionless contact of a pressurized neo-Hookean plane-strain membrane to a rigid substrate. Here, we extend our theory to include adhesion using a fracture mechanics approach. This theory is used to study contact hysteresis commonly observed in experiments. Detailed analysis is carried out to highlight the differences between frictionless and ...

In this paper, a graphical dynamic simulator is developed that can simulate actively-coordinated wheeled vehicle systems on uneven faceted terrain. Based on the considerations of model delity and computational efciency, a simple geometric model for wheel-terrain contact is proposed. In addition, a computationallye cient algorithm for contact detection is developed. We also devise a contact forc...

In this paper a semi cylindrical fluid filled hyperelastic finger model for soft contact has been developed from the basic principles of mechanics. The deformation parameters namely contact width and radial deflection were calculated for different applied forces. To validate this analytical model, compression tests were conducted on silicone rubber finger specimens . Contact width and radial de...

Revolute-jointed cobots depend on continuously variable transmissions (CVTs). CVTs constrain the speed ratio between two shafts to a particular value within a continuous range. The spherical CVT is well suited to cobots, but like other point contact transmissions, achieving good performance is challenging. We have studied the contact mechanics of the spherical CVT under certain simplifying assu...

This paper presents an application of canonical duality theory to the solution of contact problems with Coulomb friction. The contact problem is formulated as a quasi-variational inequality whose solution is found by solving its Karush– Kuhn–Tucker system of equations. The complementarity conditions are reformulated by using the Fischer–Burmeister complementarity function, obtaining a non-conve...

Stiffness-load curves obtained in quantitative atomic force acoustic microscopy (AFAM) measurements depend on both the elastic properties of the sample and the geometry of the atomic force microscope (AFM) tip. The geometry of silicon AFM tips changes when used in contact mode, affecting measurement accuracy. To study the influence of tip geometry, we subjected ten AFM tips to the same series o...

Efficient nanopowder processing requires knowledge of the powder's mechanical properties. Due to the large surface area to volume ratio, nanoparticles experience relatively strong attractive interactions, leading to the formation of micron-size porous structures called agglomerates. Significant effort has been directed towards the development of models and experimental procedures to estimate th...