Analyse des contraintes des assemblages boulonnées en composites et polymères

Abstract

For several years now, metal flanges have been increasingly replaced by flanges made of fiberreinforced plastic (FRP) materials in the public and industrial sectors. However, the norms and standards are relatively recent and are based on those developed for metals. Composites are complex anisotropic materials that do not function according to the same rules as metals. Currently, the design and calculation of FRP flanges in Section X of the ASME Boiler and Pressure Vessel Code are based on those of Section XIII without consideration to the behavior of the FRP material and without verification of adequate structural integrity. While most studies focus on specific flanges and NPS classes, this study examines the various parameters of all the suggested flange classes and sizes in Section X of the ASME code. FRP flanges have a cylindrical flange and are used with a foil gasket that spreads over the entire flat surface of the flange. An analysis of the structural integrity and tightness of these flanges is conducted considering the impact on regions of discontinuities, flange rotation, gasket flexibility and bolts that are not addressed by the ASME code. The study was conducted on flanges from ASME Section X Table RD-620.1, including NPS nominal diameters of 1 through 48 and classes 25, 50, 75, 100, 125, and 150. The parametric analysis highlights critical fiberglass reinforced plastic (FRP) flanges manufactured as laminates of vinyl ester resins and various types of fiberglass reinforcements. This study demonstrates that there is a concern with the lower-class flanges presented in the ASME BPVC Section X code and particularly class 25 for which the rotations and stresses are relatively higher than the class 50 to 150. This study covers a variety of different cases of flange size and pressure according to the Section X code and finite element and experimental analyses would greatly assist in the validity of the results. Several factors could solidify the study such as considering fiber optimization and fiber curvature between the flange and the ring.

Date	8 Dec 2022
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Anh Dung Ngô (Supervisor)