Influence of vibration loads on the strength of sheet composite elements of ship structures

The use of sheet composite elements in the repair of ship hull structures puts forward as an urgent task to determine the influence of vibration loads on the strength characteristics of structures with composite elements. The available methods for calculating metal plates under the influence of vibration loads cannot be applied to composite elements without additional research. The setup and methodology for conducting experimental studies have been developed. The loads were carried out in cycles of different duration. The obtained dependences of the ultimate strength of the material on the number of loading cycles are presented, taking into account the orientation of the studied layers relative to the applied load. In the course of research, it was found that polymer coatings are able to absorb part of the vibration load and change the natural vibration frequencies of the structure. The developed experimental setup and test procedure allow us to determine the stress-strain state of the structure with composite elements by experimental means.