Bondar N. Strength of aviation composite shells taking into account operational environment and damage

Dissertation is devoted to experimental and theoretical research of polymer composite shells under influence of operational environment and damage. Research was carried out on polypropylene and epoxy, flat and shell specimens reinforced by fiberglass and carbon fiber developed using thermal-vacuum and autoclave technology. Determination of amount of adsorbed liquid by the investigated plastics exposed to these fluids for 1000 hr. was carried out. Influence of the liquid on strength, modulus of elasticity and critical stress intensity factor of considered materials taking into account temperature is determined. Influence of operational fluid, temperature, geometric dimensions and type of reinforcement on strength of the shells and elastic modulus of the shells with and without damage was determined. Numerical calculations were conducted in ANSYS program according to experiment. A behavior model of such composite shell structures under influence of operational environment taking into account a temperature in 0 – 1000 hr. time range is proposed.