A MATHEMATICAL MODEL AND A SIMULATIONAL INVESTIGATION OF A PLANAR SYSTEM UNDER OBLIQUE MULTIPOINT IMPACT WITH FRICTION

This article presents a mathematical model of a planar system for the multipoint, oblique, and eccentric impact of rough bodies. The created model served for numerical investigations of the system’s behaviour. To analyse the influence of various parameters, three simplified cases were defined. Each of these cases focused on different aspects of the simulation. The first case was used to determine how many contacting bodies undergo impact at a given time point. This result was then compared with the experimental observations, which gave good agreement. The second case investigated the influence of the body configuration and the coefficient of friction (COF) on the sliding process during impact. Depending on the parameter values, the sliding process was divided into three main areas: slip-reversal slip, slip-stick, and continuous slip with increasing sliding velocity. The third case focused on the energy dissipation expressed by the coefficient of restitution (COR) and the angle of incidence of the initiating impact; this case showed possible improvement areas of the used impact force model.

Experimental and Simulation of a Cam and Translated Roller Follower Over a Range of Speeds

In this study a cam and follower mechanism is analyzed. There is a clearance between the follower and the guide. The mechanism is analyzed using SolidWorks simulations taking into account the impact and the friction between the roller follower and the guide. Four different follower guide’s clearances have been used in the simulations like 0.5, 1, 1.5, and 2 mm. An experimental set up is developed to capture the general planar motion of the cam and follower. The measures of the cam and the follower positions are obtained through high-resolution optical encoders (markers). The effect of follower guide’s clearance is investigated for different cam rotational speeds such as 100, 200, 300, 400, 500, 600, 700 and 800 R.P.M. Impact with friction is considered in our study to calculate the Lyapunov exponent. The largest Lyapunov exponents for the simulated and experimental data are analyzed and selected.

Study of the Planar Rocking-Block Dynamics With Coulomb Friction: Critical Kinetic Angles

The objective of this paper is to show, through the planar rocking block example, that kinetic angles play a fundamental role in multiple impact with friction. Even in the presence of Coulomb friction, a critical kinetic angle θcr is exhibited that allows one to split the blocks into two main classes: slender blocks with a kinetic angle larger than θcr, and flat blocks with a kinetic angle smaller than θcr. The value of θcr varies with the friction value, but it is independent of the restitution coefficient (normal dissipation). Numerical results are obtained using a multiple impact law recently introduced by the authors. Some comparisons between numerical and experimental results that validate the used model and numerical scheme are presented. However, this paper is mainly based on numerical simulations.