Research Article Impact Behavior of a Rotating Rigid Body with Impact and Viscous Friction Dorian Cojocaru 1 and Dan B. Marghitu 2 1 Department of Mechatronics and Robotics, University of Craiova, Craiova, Romania 2 Department of Mechanical Engineering, Auburn University, Auburn, AL 36849, USA Correspondence should be addressed to Dorian Cojocaru; cojocaru@robotics.ucv.ro Received 27 July 2020; Revised 11 September 2020; Accepted 17 October 2020; Published 3 November 2020 Academic Editor: Stylianos Georgantzinos Copyright©2020DorianCojocaruandDanB.Marghitu.isisanopenaccessarticledistributedundertheCreativeCommons AttributionLicense,whichpermitsunrestricteduse,distribution,andreproductioninanymedium,providedtheoriginalworkis properly cited. eimpactbetweenarotatinglinkandasolidflatsurfaceisconsidered.Fortheimpact,weconsiderthreedistinctperiods:elastic period,elastoplasticperiod,andrestitutionperiod.AHertziancontactforceisconsideredfortheelasticperiod.Nonlinearcontact forces developed from finite element analysis are used for the remaining two phases. e tangential effect is taken into account consideringafrictionforcethatcombinestheCoulombdryfrictionmodelandaviscousfrictionfunctionofvelocity.Simulations results are obtained for different friction parameters. An experimental setup was designed to measure the contact time during impact. e experimental and simulation results are compared for different lengths of the link. 1. Introduction e study of the mechanical impact has a very long history starting from Maclaurin, Newton, and Poisson. ey have produced impressive number of studies for different ap- plications, and a diversity of practical benches were used to verify the theoretical approaches. An important improvement for this technical domain was produced through the development of new modern fieldsofengineeringascomputeraideddesign,robotics,and biomechanics. Modern sensors, high speed image acquisi- tion, and processing devices and increased computer re- sourcesbettersupporttheabilityforpracticalverificationof the theoretical models. e diversity of applications must take into consideration the shape of impacting bodies, the materials, and the dynamics conditions including angles, speeds, accelerations and frictions. Differentsurfacesfortheimpactwereconsidered:rod withaflatsurface[1],spherewithaflat[2,3],rotorsystem into a film damper [4], elastic wedges [5], sphere on a beam[6],anisotropicbisinusoidalsurfaceandarigidbase [7], cylindrical body with a rigid plane [8], superball [9], tennis ball with a racket [10], and 3D-printed polymers under collision with a rigid rod [11]. Different types of behaviors depending of the nature of the constituent materials of the impacting bodies were studied: elasto- plasticimpact[2,3,6,8,12–14],nonlinearelastic[1,15], elastic [16], elastic-perfectly plastic [17], and nearly complete elastic [14, 18]. e material properties were studied from the point of view of the influence of the impact behavior: incompressible isotropic [5], nano- particles [15], 3D-printed polymers [11], transmembrane domains [19], stable CuO nanoparticle enhanced lubri- cants [16], Al-6061 instrumented spherical micro- indentation and microstructurally graded samples [20], and various finishes [21]. e direction of the impact is another factor to be considered in modeling the impact: normal [6], oblique [10, 13, 22], normal, and tangential [7]. Frictioncouldhaveanimportanteffectinmanypractical applicationsandbyconsequencethetheoreticalmodelmust be adapted. Studies have considered the effect of friction in combination with other influences such as strain hardening [12], wear [15], lubrication [16], and deformation [22]. Better solutions for applications involving impacts with friction were proposed as the treatment of impact for the Hindawi Mathematical Problems in Engineering Volume 2020, Article ID 5471629, 11 pages https://doi.org/10.1155/2020/5471629