Shape Factors for Irregular Glass Reinforced Plastic Pipes – An Analytical and Numerical Approach

Abstract

This paper presents the development of a mathematical model based on curved beam theory of composite pipes with irregular shapes under diametral loading. The analytical solution was validated through finite element models of the same pipe shapes under similar loading conditions. Four shapes (circular, elliptical, rectangular, and egg shaped pipes) were considered in this study. The analytical and finite element results were used to estimate the shape factor defined by the ratio of the maximum tangential stress of an irregular shape over the maximum tangential stress for a circular pipe. Comparison of the load-deflection curves for the four different shapes revealed that the egg pipe is the stiffest among the rest of the pipes while the square shape is the most flexible one. The analytical solution and finite element results were used to determine the shape factor for the four pipe shapes taking into account the circular pipe as the base shape. Both results were in good agreement and can be used as design guidelines for the irregular shapes without resorting to the conduct of any further testing.

Shape Factor for Glass-Reinforced Plastic Pipes With Noncircular Shapes Under Diametral Loading - An Experimental Study

“…Figure 5 also shows that failure takes place only in circular samples at a lower load because of its high stiffness characteristics as compared to other shapes. Interpretation of the results depends on the pipe shape under consideration and only maximum tensile strains were considered in this paper to estimate the shape factor, K S (see 10,11 ), which is defined as the ratio of maximum recorded strains of noncircular to circular pipes at an axial load of 5 kN according to ASTM D 3262. Details of can be found in Refs.…”

“…Therefore, the flat elliptical pipe is more susceptible to failure than other shapes. A comparative study conducted by Kalfat et al 10,11 revealed a good agreement between the experimental data and simulated results. Table 3 summarizes a comparison between analytical, finite element analysis (FEA), and experimental results.…”

“…Interpretation of the results depends on the pipe shape under consideration and only maximum tensile strains were considered in this paper to estimate the shape factor, K S (see Eq. 2 10,11 ), which is defined as the ratio of maximum recorded strains of noncircular to circular pipes at an axial load of 5 kN according to ASTM D 3262. Details of Eq.…”

The Effect of Silane Treatment on Tensile Properties and Morphology of Polypropylene/Recycled Acrylonitrile Butadiene Rubber/Rice Husk Powder Composites

“…The SEM micrographs shows that poor adhesion of RHP to the PP/NBRr matrix is the main factor for the reduction of the tensile strength with an increasing of filler loading in the composites. The incorporation of RHP filler into the PP/NBRr matrix increase the rigidity of the material thus reduces the ductility of the composites [11,13]. Figure 4(a) some noticeable gaps between the filler and matrix which is the evident of poor adhesion between the filler and matrix.…”