EVALUATION OF FATIGUE LIFE AND SERVICE LIFE OF THE BOAT BODY OUTER COMPOSITE SKIN

It is known that for many years various polymer composite materials have been widely used in the design and manufacture of boats structural elements. The estimated service life of modern boats is, as a rule, at least 20 years, during which the necessary level of fatigue strength of such elements must be provided. It is noted that the problem of ensuring the design life of composite elements in the body of boats is currently being solved mainly by providing a reduced level of design stresses and analyzing operational experience. As a rule, any calculated estimates of the fatigue life of these elements are not carried out. At the same time, the need for such assessments is now obvious. In order to form a method suitable for such assessments, the main provisions of methods for fatigue life evaluations of elements made of layered composites in aircraft structures are considered. Based on the analysis of these provisions, a method for fatigue life and service life evaluations of the outer composite skin of the boat body is proposed. Using the proposed method, a test calculation of the outer composite skin of the boat body about 60 meters long made of intact fiberglass of the “rovimat” type with the laying layers at an angle of 450 and the same fiberglass with impact damages is performed. The results obtained have shown that the service life of the skin with impact damages is significantly less than the estimated service life of a boat of 20 years. The obtained result has shown the need to introduce periodic inspections and control of the outer composite skin during the operation of the boat.

polymer composite materials, fatigue life, service life, damage summation rule, reliability coefficient, outer composite skin, impact damage, boat body

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