Structural and functional failure pressure of filament wound composite tubes

Reviewing some design issues for filament wound composite tubes

“…Modeled glass fiber reinforced polymer (GFRP) tubes were fabricated using the filament winding process and cured inside an oven according to the recommended cure schedule (2 h/ 80°C + 2 h/120°C) [25,26]. The length and internal radius of the tubes are given in Fig.…”

“…The numerical models used in these parametric studies were validated with burst tests of composite tubes performed in a pressurizing system according to previous works [25,26]. In the same way, convergence analysis was performed to select the meshes used and to decrease the computational costs.…”

“…In this way the problem was reduced to an eighth of its original. Moreover, in order to induce progressive failure, the meshes had a gradual change in thickness near the plane of symmetry following the thickness mapping from previous studies [25,26]. Typical boundary conditions used in the analyses of the tubes are illustrated in Fig.…”

“…With this technique the damage variables calculated from the aforementioned damage evolution equations are not used directly; instead, the damage variables are ''regularized'' via the following equations: [25,26]. For open-end condition, the viscosity value of 0.03 was assumed because no hydrostatic tests were made for calibration of the models and because of the similarity between restrained and open-end condition.…”

The effect of residual stresses and wind configuration on the allowable pressure of thick-walled GFRP pipes with closed ends

“…This, together with the fact that the presence of the resin system affects the mechanical response of a GFRP pipe, brings the validity of the 'optimum' wind angle into question. In this respect, numerous investigations (Spencer and Hull 1978;Martins et al 2012;Onder et al 2009) have been performed in the form of pressure tests to determine whether ±55°is actually the 'optimum' wind angle. These works indicate that this is, in fact, true for both weep and burst pressure.…”