PSI - Issue 59

Victor Aulin et al. / Procedia Structural Integrity 59 (2024) 428–435 Victor Aulin et al./ Structural Integrity Procedia 00 (2019) 000 – 000

429

2

1. Introduction Durability of nodes, systems and aggregates of machines and mechanisms during operation has been determined by the parameters of the surface strength of the tribo-joint parts materials. An intensive wear of their working surfaces, when the normal friction regime is violated, leads to the appearance of a number of negative phenomena: loss of tightness of the friction unit, vibration, jamming, increased noise during operation. The formation of the foundations of a unified theory of friction, oil and wear, the development of progressive designs of friction nodes, the use of highly effective materials for tribo-coupling parts (anti-friction, friction), oil media, the development of complex research methods (universal friction machines, kinetic evaluation criteria), creating a bank of tribotechnical data for effective management of friction and wear processes in the area of frictional contact are the main scientific and practical tasks of modern tribology. A parametric scheme for the study of friction and wear processes has been developed from the positions of the structural-energy theory of friction, wear and the main provisions of system analysis in tribology (Kostetskyi 1976; Aulin 2014; Dykha et al., 2021.; Haiday et al., 2021) (Fig. 1).

EXIT Power load parameters* Materials of tribojunctions samples and parts Oil materials (additives) External environment (active elements) Geometric parameters of tribocoupler parts (scale factor) Topography of initial friction surfaces

TRANSFORMATION Formation, transformation, destruction of dissipative secondary structures of various types Change in entropy of triboconjugation of details Energy dissipation of tribocouples samples and parts Mass transfer Chemical reactions Change in topography of friction surfaces Change in the rheological properties of oil material Exchange of energy and matter with the external environment.

ENTRANCE Amount of wear

Coefficient of friction Contact temperature of tribojunctions of samples and details The work of frictional forces Contact electrical resistance of tribojunctions of samples and parts Actual contact area Structural and energetic parameters of dissipative secondary structures and their topography

Information parameters

Synergy of friction and wear processes

SECONDARY INFLUENCE FACTORS (CONSTRUCTIONAL, TECHNOLOGICAL, OPERATIONAL) Vibration of tribocouples of samples and parts. Rigidity of tribocouplers of samples and parts and their loading mechanism. Heterogeneity of material properties of tribojunction parts and samples. A change in the properties of oil material. Heat removal and cooling system. Wear products in the contact area. Protection of triboconjugation of samples and parts against the influence of abrasive.

Fig. 1. Parametric scheme for the study of tribocouples samples and parts (system analysis). *- Р – specific load, V – sliding speed.

2. Experimental device and methodology Laboratory studies of friction and wear processes, including heavily loaded tribo couplings of samples and car parts, have been carried out using a universal friction machine, the design features of which (drive mechanisms and force load of the friction unit) allow to study a wide range of materials of tribo couplings of samples, oil media in a wide range of values power parameters of the load with their smooth change (Maruschak et al., 2016) (fig. 2). The