Evaluation of cracked construction elements durability and estimation of structural strength under vibrations

The manuscript deals with the research of relevant problems of cracked elements under cyclic loading. In contrast to the majority of published research work that is dedicated to the case of symmetrical cyclic loading, this paper proposes a methodology for evaluation of influence of asymmetric cyclic loading. First part of the manuscript is concerned with straight crack growth dependence on loading parameters using probabilistic analysis. Speed of crack growth and stress intensity factor values are obtained from experimental studies. Assessment of these parameters can be made using method of Monte Carlo however it is not common and the current research is carried out by applying a more simple averaging method. For elements under asymmetrical loading a general-purpose equation is proposed. Symmetrical cycle and pulsing cycle parameters are used. As a result of these two parameters a general equation is obtained for computational number of loading cycles. This technique enables estimation of durability of elements under various types of loadings with the defined size of the crack