Influence of Scratches on the Stiffness Properties of Thin-walled Elements

One of the reasons of the structural failure is an existence of surface defects, especially scratches. The paper describes experimental and theoretical method of determining tangential and bending stiffness of the thin-walled elements with a system of scratches. The results of the research are presented, the analysis of the impact the scratches parameters on the stiffness characteristics of thin-walled elements is done, models of the fluctuations of the tangential and bending stiffness are designed, summaries and recommendations are suggested.