The creep crack problems in damaged materials under mixed mode loading (Mode I and Mode II loading) in the framework of creep-damage coupled formulation are considered. The class of the self-similar solutions to the plane creep crack problems in a damaged medium under mixed-mode loading is given. With the similarity variable and the self-similar representation of the solution for a power-law cr...

In the present work, the mechanical behavior of stress corrosion cracking phenomenon is described. Such phenomenon presents strong complexity due to metallurgic and electrochemical aspects. A methodology for modeling both SSR (Slow Strain Rate) and CL (Constant Load) tests based upon thermodynamics of continuum solids and elastoplastic damage is proposed. In this macroscopic approach, besides t...

This paper outlines a science-based explanation of damage and reliability of critical components and structures within the second law of thermodynamics. The approach relies on the fundamentals of irreversible thermodynamics, specifically the concept of entropy generation as an index of degradation and damage in materials. All damage mechanisms share a common feature, namely energy dissipation. ...

The goal of damage-mitigating control is to enhance structural durability of mechanical systems (e.g., advanced aircraft, spacecraft, and power plants) while retaining high performance. So far the reported work in damage-mitigating control has focused on reduction of peak stresses to increase structural durability. This paper presents a novel concept that takes advantage of the physical phenome...

Damage parameters for crack initiation in Single Lap Joint (SLJ) are determined by combining continuum damage mechanics, Finite Element Analysis (FEA) and fatigue experimental data. Even tough SLJ has a simple configuration; the stresses in the adhesive region are quite complex and exhibit a multi-axial state. Such a condition leads to the need to introduce a general value of triaxiality functi...

Sharing a damage that has been caused jointly by several tortfeasors is analyzed from a normative point of view. We show how a damage can be apportioned on two distinct basis, causation and degree of misconduct. Our analysis uses the concept of potential damage on the basis of which we define a transferable utility game. Its core defines acceptable judgments as allocations of the total damage a...

Cohesive laws describe the resistance to incipient separation of material surfaces. A cohesive finite element is formulated on the basis of a particular cohesive law. Cohesive elements are placed at the boundary between adjacent standard volume finite elements to model fatigue damage that leads to fracture at the separation of the element boundaries per the cohesive law. In this work, a cohesiv...

This paper compares in simulation six different nonlinear control laws for multi-axis control of a high performance aircraft. The control law approaches are fuzzy logic control, backstepping adaptive control, neural network augmented control, variable structure control, and indirect adaptive versions of Model Predictive Control and Dynamic Inversion. In addition, a more conventional scheduled d...

Brainstem death and brain death although practically same with regards to the concept of organ donation, remain technically different. Brain death mandates irreversible cessation of all the functions of the entire brain and brainstem while brainstem death signifies irreversible damage to the brainstem. As per the Indian law, brainstem death is the legal requirement and not brain death.