We investigate the macroscopic properties of frictionless nonconvex particles using molecular dynamics. The calculations are based on a simple and efficient method to simulate complex-shaped interacting bodies. The particle shape is represented by Minkowski operators. A multicontact time-continuous interaction between bodies is derived using simple concepts of computational geometry. Three-dime...

This paper is concerned with the discretization error analysis of semilinear Neumann boundary control problems in polygonal domains with pointwise inequality constraints on the control. The approximations of the control are piecewise constant functions. The state and adjoint state are discretized by piecewise linear finite elements. In a postprocessing step approximations of locally optimal con...

The basic friction angle (φb) tests are a common and practical method used to determine the shear strength of discontinuities. Tilt device is generally in experiments. In this study, effects anisotropy properties green mica schist rocks taken from copper mine site Kastamonu Hanönü district on residual angles were investigated. For purpose, experiments with specially designed tilt conducted drie...

Superhydrophobic surfaces have considerable technological potential for various applications due to their extreme water-repellent properties. A number of studies have been carried out to produce artificial biomimetic roughness-induced hydrophobic surfaces. In general, both homogeneous and composite interfaces are possible on the produced surface. Silicon surfaces patterned with pillars of two d...

The dynamic and friction parameters of a redundantly actuated parallel manipulator are identified by using the Weighted Least Square (WLS) method. The dynamic model with nonlinear friction is formulated in the joint space for the parallel manipulator, and it is expressed in its linear matrix form with respect to the dynamic and friction parameters. In the WLS method, the difference algorithm of...

Superlubricity of graphite and graphene has aroused increasing interest in recent years. Yet how to obtain a long-lasting superlubricity between graphene layers, under high applied normal load in ambient atmosphere still remains a challenge but is highly desirable. Here, we report a direct measurement of sliding friction between graphene and graphene, and graphene and hexagonal boron nitride (h...

Inspired by peg-studded hexagonal epidermal cells found in biological pad interfaces, biomimic hierarchical surface patterns with different degrees of wettability were fabricated using a new method involving photolithography and wet etching. In order to understand the effects of the peg-studded structures on wettability and frictional properties, varying patterns were studied and compared. Expe...

Rough terrain control optimization for space rovers has become a popular and challenging research field. Improvements can be achieved concerning power consumption, reducing the risk of wheels digging in and increasing ability of overcoming obstacles. In this paper, we propose a terrain profiling and wheel speed adjustment approach based on terrain shape estimation. This terrain estimation is pe...

I.4: “If two triangles have the two sides equal to two sides respectively, and have the angles contained by the equal straight lines equal, they will also have the base equal to the base, the triangle will be equal to the remaining angles respectively, namely those which the equal sides subtend.” I.9: “To bisect a given rectilinear angle.” I.10: “To bisect a given finite straight line.” I.11: “...