Refined thickness of filament wound shells

Refined thickness equations of composite shell are satisfactory except in the polar boss region. The deviation indicates there are factors such as fiber movement and roving separation that must be accounted for in predicting the shell thickness near the dome opening. Using condition of total volume preservation of all bands that are within two-band width of the polar boss the thickness distribution in polar region is approximated by cubic polynomial. Thickness at the polar radius is determined which better predicts actual thickness at radius of polar boss. The suggested model is compared with the actual measured thickness of isotensoid pressure vessel domes and spherical composite shell and has a good agreement.