Abstract

Fiber reinforced plastic (FRP) materials have been used in the chemical and process industries for several decades, chiefly because of the ability of many FRP materials to resist attack by various chemicals. FRP tanks, pressure vessels and piping have successfully been used to replace expensive equipment formerly made in stainless steel or nickel alloys. Although the laminate theory has been used to establish design formulas for cylindrical and spherical shells, little work has been done to investigate bolted flanged connections. The ASME Boiler and Pressure Vessel Code or the codes of other industrialized countries do not include specific rules for the design of FRP bolted flanged connections. Up to now, the only work done on fiber reinforced plastic flanges has either been experimental investigations, or finite element analyses. No attempt has been made on a stress analysis of bolted flanged connections based on the laminate theory. Thus the current design practice is merely an extension of metallic flange design methods. In this dissertation, two methods are proposed for a stress analysis of fiber reinforced plastic flanged connections with full face gaskets, using classical and shear deformation laminate theory, respectively. A sample calculation using the first proposed method is included. In order to verify the analytical results, a finite element analysis with 3-D anisotropic layered solid elements, using ANSYS is performed. Finally, an experimental investigation into the effects of outside to inside diameter ratios on the flange stress distribution and maximum stress values is conducted.