In general, joints are assumed without clearance in the dynamic analysis of multi-body echanical systems. When joint clearance is considered, the mechanism obtains two uncontrollable degrees of freedom and hence the dynamic response considerably changes. The joints’ clearances are the main sources of vibrations and noise due to the impact of the coupling parts in the joints. Therefore, the syst...

Response modification factors (R-factor) are used in current seismic building codes to reduce earthquake forces associated with seismic design level to determine force levels. In recent years, many authors have shown great interest in the development of seismic structural systems and several theoretical and experimental studies have been conducted to investigate performance of dampers but littl...

Analysis and estimation of friction and compensation for its effects in the control of an electrohydraulic manipulator is addressed in this paper. The specific hydraulic manipulator is an integral part of an automated fish processing machine which has been developed in our laboratory. The analysis reveals that considerable static and dynamic friction exists in the system. An available nonlinear...

Friction in an ambient condition involves highly nonlinear interactions of capillary force, induced by the capillary-condensed water nanobridges between contact or noncontact asperities of two sliding surfaces. Since the real contact area of sliding solids is much smaller than the apparent contact area, the nanobridges formed on the distant asperities can contribute significantly to the overall...

In this paper, adaptive friction compensation is investigated using both model-based and neural network (non-model-based) parametrization techniques. After a comprehensive list of commonly used models for friction is presented, model-based and non-modelbased adaptive friction controllers are developed with guaranteed closed-loop stability. Intensive computer simulations are carried out to show ...

This work concerns the modelling and experimental verification of the highly nonlinear friction behavior in positioning on the nanometer scale. The main goal of this work is to adjust and identify a simple dynamic friction model which allows a model-based estimation of the friction force in combination with the system inertia against displacement. Experiments in the pre-sliding and sliding fric...

In this note, it is shown that the differential equation with discontinuous right-hand side, which describes the dynamic behavior of a mechanical system with friction, has a Carathèodory solution. This result supports theoretically the prior work on the control of mechanical systems with friction, which assumes the existence of Carathèodory solutions without proof.

Six maxillofacial materials were evaluated by determining their dynamic properties with use of a Goodyear Vibrotester. The dynamic modulus, internal friction, and dynamic resilience were measured for all materials over a temperature range of -15 to 37 C. The dynamic modulus ranged from 11.1 to 124.8 kg/cm2 and the dynamic resilience varied from 1.1 to 63.5%.