In this paper, we formulate a semi-implicit time-stepping model for multibody mechanical systems with frictional, distributed compliant contacts. Employing a polyhedral pyramid model for the friction law and a distributed, linear, viscoelastic model for the contact, we obtain mixed linear complementarity formulations for the discrete-time, compliant contact problem. We establish the existence a...

An investigation into the properties of granular materials is undertaken via numerical simulation. These simulations highlight that frictional contact, a defining characteristic of dry granular materials, and interfacial debonding, an expected deformation mode in plastic bonded explosives, must be properly modeled. Frictional contact and debonding algorithms have been implemented into FLIP, a p...

Rolling allows leukocytes to maintain adhesion to vascular endothelium and to molecularly coated surfaces in flow chambers. Using insights from adhesive dynamics, a computational method for simulating leukocyte rolling and firm adhesion, we have developed a semianalytic model for the steady-state rolling of a leukocyte. After formation in a force-free region of the contact zone, receptor-ligand...

When contacting elastic systems are subjected to periodic loading, frictional slip occurs resulting in energy dissipation. Here we investigate the effect of the relative phase of harmonically varying tangential and normal loads on the frictional dissipation in a very simple uncoupled frictional system. We demonstrate that this effect is substantial when the system experiences periods of separat...

We propose a new explicit contact algorithm for finite element discretized solids and shells with smooth and nonsmooth geometries. The equations of motion are integrated in time with a predictor-corrector type algorithm. After each predictor step, the impenetrability constraints and the exchange of momenta between the impacting bodies are considered and enforced independently. The geometrically...

We have studied the variation of frictional force with externally applied load for a Pt-coated atomic force microscope tip in contact with the surface of mica cleaved in ultrahigh vacuum. At low loads, the frictional force varies with load in almost exact proportion to the area of contact as predicted by the Johnson-KendallRoberts ( JKR) theory [K. L. Johnson, K. Kendall, and A. D. Roberts, Pro...

The construction of fast and reliable solvers for contact problems with friction is even nowadays a challenging task. It is well known that contact problems with Coulomb friction have the weak form of a quasi-variational inequality [KO88, HHNL88, NJH80]. For small coefficients of friction, a solution can be obtained by means of a fixed point iteration in the boundary stresses [NJH80]. This fixe...

The contacts between cohesive, frictional particles with sizes in the range 0.1–10μm are the subject of this study. Discrete element model (DEM) simulations rely on realistic contact force models—however, too much details make both implementation and interpretation prohibitively difficult. A rather simple, objective contact model is presented, involving the physical properties of elastic–plasti...

Indentation hardness has been used extensively for material characterization and many recent computational studies have established quantitative relationships between elasto-plastic mechanical properties and the response in instrumented indentation. In contrast, very few studies have systematically quantified the effect of the plastic deformation characteristics on the frictional sliding respon...

Antimony nanoparticles deposited under UHV conditions on HOPG are found to exhibit an intriguing frictional behavior characterized by a distinct clearly separated double dual behavior of dependence of the frictional force on contact area. We present the first realistic simulations, density functional modeling adapted to accommodate van der Waals interactions, of the (double) dual frictional beh...