Introduction to Thermodynamics of Mechanical Fatigue

Content: Introduction to Mechanical Degradation Processes Fatigue Fracture Wear Fretting Brinelling and False Brinelling Corrosion Creep Thermal Shock Impact References Fundamentals of Thermodynamics Open and Closed Systems Equilibrium and Nonequilibrium State Steady and Unsteady State Stable and Unstable State The First Law of Thermodynamics The Second Law of Thermodynamics Entropy Flow and Entropy Generation Entropy Balance Equation References Degradation-Entropy Generation (DEG) Theorem Thermodynamic Forces and Flows Relations between Thermodynamic Forces and Flows The Degradation-Entropy Generation Theorem References Fatigue Mechanisms: An Overview Multiscale Characteristics of Fatigue Parameters Influencing Fatigue and Classification of Regimes Fatigue and Energy Dissipation Fatigue-Temperature Rise References Basic Thermodynamic Framework for Fatigue Analysis Entropy Balance Equation of a Deformed Body Entropy Change of a Thermally Deformed Solid Clausius-Duhem Inequality Thermodynamic Forces and Flows in Fatigue References Thermodynamic Assessment of Fatigue Failure Limitation of Conventional Methods and the Need for Further Advances Evaluation of Entropy Generation and Entropy Flow Time to Failure References Damage Mechanics: An Entropic Approach Introduction to Damage Mechanics Continuum Damage Mechanics (CDM) References Self-Organization in Fatigue Introduction to Self-Organization Effect of Electric Current on Fatigue Life Effect of Magnetic Field on Fatigue Life Effect of Environment (Surface Cooling) on Fatigue Life Self-Organization and Complexity References Entropic Fatigue: In Search for Applications Application to Variable-Loading Amplitude and Structural Health Monitoring Accelerated Fatigue Testing Concluding Remarks References Index
Abstract: "Preface The subject of fatigue degradation and methodologies for its treatment spans multitudes of scientific disciplines ranging from engineering to materials science, and from mechanics to mathematics. Fatigue is probabilistic in nature. For example, fatigue tests performed on the same material subjected to the same operating conditions can yield different results in terms of the number of cycles that the system can withstand before failure occurs. Such uncertainties affect the system design, its structural integrity, and operational reliability. Yet the majority of available methods for prediction of fatigue failure--such as cumulative damage models, cyclic plastic energy hypothesis, crack propagation rate models, and empirically-derived relationships based on the curve fitting of the limited laboratory data--are based on deterministic- type theories and their applications require many unknown input parameters that must be experimentally determined. There are other complications. All of the above-mentioned methods concentrate on very specific types of loading and single fatigue modes, that is, bending, or torsion, or tensioncompression. In practice, however, fatigue involves simultaneous interaction of multimode processes. Further, the variability in the duty cycle in practical applications may render many of these existing methods incapable of reliable prediction. It is, therefore, no surprise that the application of these theories often leads to many uncertainties in the design. Further, their use and execution in practice requires one to implement large factors of safety, often leading to gross overdesigns that waste resources and cost more"