Interdependence of friction, wear, and noise: A review

Phenomena of friction, wear, and noise in mechanical contacts are particularly important in the field of tribomechanics but equally complex if one wants to represent their exact relationship with mathematical models. Efforts have been made to describe these phenomena with different approaches in past. These efforts have been compiled in different reviews but most of them treated friction, wear mechanics, and acoustic noise separately. However, an in-depth review that provides a critical analysis on their interdependencies is still missing. In this review paper, the interdependencies of friction, wear, and noise are analysed in the mechanical contacts at asperitical level. The origin of frictional noise, its dependencies on contact’s mechanical properties, and its performance under different wear conditions are critically reviewed. A discussion on the existing mathematical models of friction and wear is also provided in the last section that leads to uncover the gap in the existing literature. This review concludes that still a comprehensive analytical modelling approach is required to relate the interdependencies of friction, noise, and wear with mathematical expressions.

Predictive Modeling of Surface Wear in Mechanical Contacts under Lubricated and Non-Lubricated Conditions

The surface wear in mechanical contacts under running conditions is always a challenge to quantify. However, the inevitable relationship between the airborne noise and the surface wear can be used to predict the latter with good accuracy. In this paper, a predictive model has been derived to quantify surface wear by using airborne noise signals collected at a microphone. The noise was generated from a pin on disc setup on different dry and lubricated conditions. The collected signals were analyzed, and spectral features estimated from the measurements and regression models implemented in order to achieve an average wear prediction accuracy of within 1mm3.

Transitions between nanomechanical and continuum mechanical contacts: new insights from liquid structure

This work reveals the transitions between nanomechanical and continuum contact behaviours at wet quartz interfaces, providing new ways to quantify the liquid structure of interfacial water to study the origin of nanomechanical contact behaviour.

RANCANGAN RANGKAIAN ANTI BOUNCING UNTUK RANGKAIAN DIGITAL

Push-On switches or toggle switches and mechanical relays are mechanical contacts made of metal which, when supplied with electric current, will result in a spike of electrical sparks, called Bouncing Effects. Bounce effects are often a problem in digital circuits, especially in digital electronics circuits, because these Bounce Effects will cause the value of data or signals coming into the circuit inaccurate or indeterminate, when the mechanical switch is pressed as input data. This will undoubtedly lead to undesirable conditions and must be overcome with an electronic circuit called De-Bounce for the data or input signal to be more certain.

Rehabilitation of an Old Traditional Elevator Based on PLC Techniques

This paper describes the rehabilitation and developing of an old didactic traditional elevator available in the laboratory. The authors tried to merge the programmable logic controller (PLC) with the elevator's traditional electric circuit for developing its control circuitry. The PLC employed in this research is Simatic (s7-200), it was used to replace the old control system of the elevator which had high faults that were due to its complex wiring and numerous mechanical contacts which were able to burn out or could result in bad contacts. The obtained results were satisfactory because the merging procedure between the traditional and the modern systems is successfully implemented; personnel safety is improved and electromechanical problems were decreased