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Semi-autonomous control systems applied to automobiles are Advanced Driver Assistance Systems (ADAS) that have gained importance from similar devices with applications in robotics. The control sharing between humans and automatic controllers is the main characteristic of these systems, and can be accomplished through various different manners. However, the use of Artificial Intelligence (AI) techniques for this purpose remains unexplored. In this paper we propose the design of a semi-autonomous control system applied to military vehicles through the use of Fuzzy Inference Systems for the definition of the controller intervention level. Simulations of a vehicle being operated in highly dangerous situations, represented by the existence of hostile military threats or by unexpected maneuvers that could put the stability of the car at risk were performed.

In this work, a review of plasticity induced crack closure is presented, along with models proposed to quantify its effect on the subsequent crack growth rate. The stress state dependence of crack closure is discussed. Overload-induced retardation effects on the crack growth rate are considered, based on the crack closure idea, and improvements to the traditional models are proposed to account for crack arrest and crack acceleration after compressive underloads. Using a general-purpose fatigue design program, the models and the proposed modifications are compared with experimental results from various load spectra, and with simulated histories illustrating their main features.

The traditional εN procedures are inconsistent when modeling nominal stresses by Hooke's law and the stresses and strains at the critical notch root by Ramberg-Osgood's equation, since the material is the same at both regions. When the nominal stresses are not substantially smaller than the yielding strength SY, the predicted hysteresis loops at the notch root can be significantly non-conservative. In fact, when the nominal stresses are in the order of SY, the Hookean model can predict stresses and strains at the notch root that are smaller than the nominal ones, a clear non-sense. To avoid this problem, it is mandatory to use Ramberg-Osgood to model both the nominal and the critical stresses and strains. However, this approach is not trivial to implement, especially when complex loads are involved. In this work, the methodology required to warrant correct numerical predictions of the critical loops under high nominal loads are discussed.