Abstract

Mechanics from its side and thermodynamics from its side consider evolution of complex systems, including the Universe. Created classical thermodynamic theory of evolution has one important drawback since it predicts an inevitable heat death of the Universe which is unlikely to take place according to the modern perceptions. The attempts to create a generalized theory of evolution in mechanics were unsuccessful since mechanical equations do not discriminate between future and past. It is natural that the union of mechanics and thermodynamics was difficult to realize since they are based on different methodology. We make an attempt to propose a generalized theory of evolution which is based on the concept of tribo-fatigue entropy. Essence of the proposed approach is that tribo-fatigue entropy is determined by the processes of damageability conditioned by thermodynamic and mechanical effects causing to the change of states of any systems. Law of entropy increase is formulated analytically in the general form. Mechanothermodynamical function is constructed for specific case of fatigue damage of materials due to variation of temperature from 3 K to 0.8 of melting temperature basing on the analysis of 136 experimental results.

Highlights

  • As is known, any scientific discipline serves and aims at understanding and describing these or those regularities and features of certain phenomena, situations, events caused by the existence of some real or thinkable objects that manifest themselves their specific properties [1,2]

  • Consider the statement of thermomechanical problem [5,6,7,8] needed for further development of models of energy and entropy states of mechanothermodynamical systems

  • Within the framework of mechanothermodynamics a special approach is being developed to assess the entropy in terms of a generalized energy state

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Summary

Introduction

Any scientific discipline serves and aims at understanding and describing these or those regularities and features of certain phenomena, situations, events caused by the existence of some real or thinkable objects that manifest themselves their specific properties [1,2]. A damage evolution model based on thermodynamic theory is developed in works [33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60] According to this model irreversible entropy production rate under loadings of different nature is considered as a single universal damage term—damage metric. This has made it possible to reveal and investigate new regularities of the behavior and evolution of the mechanothermodynamical system

Thermomechanical Statement
Main Principles
Energy Theory of Damage and Limiting States
Mechanothermodynamical States
Laws of Mechanothermodynamics
Conclusion
H Y StheI basic
Tribo-Fatigue
Analysis of Experimental Data
Conclusions
Full Text
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