PSI - Issue 82

Igor Guz et al. / Procedia Structural Integrity 82 (2026) 239–245 I. Guz et al./ Structural Integrity Procedia 00 (2026) 000–000

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arranged symmetrically about the core, i.e. the stacking sequence is [-φ/+φ/core/+φ/-φ]. Properties of unidirectional T300/LY5052 and neat LY5052 are presented in (Hastie et al., 2019a, 2019b, 2021). Cylindrical stresses computed using the FE model are shown alongside those presented by Bakaiyan and Ameri (2012) in Fig. 2 for two cases. In case 1 the pipe is subjected to internal pressure of 10 MPa and has fibre angle of φ=55°. In case 2, the pressure is applied simultaneously with internal and external surface temperatures of 121 o C and 67 o C respectively and the fibre angle is φ=60°. Close agreement between results demonstrates suitability of the FE model for thermomechanical stress analysis of composite sandwich pipe.

Fig. 2. Cylindrical stresses in FW sandwich pipe computed using FE model and solved analytically by Bakaiyan and Ameri (2012).

4. Numerical results Here, an example FEA is performed for the sandwich pipe with carbon/epoxy skins (φ=60°) and homogeneous epoxy, homogeneous polyvinyl chloride (PVC) or graded-density PVC core. Properties of Divinycell PVC foam with different density are used as in (Diab, 2022). The configurations are illustrated in Fig. 3 (the graded core comprises four layers of equal thickness). The masses per metre length are given in Table 1.

Table 1. Sandwich pipe mass per metre. Configuration

Mass per m (kg/m)

Epoxy core HP60 core

5.36 1.47 2.12 1.76

HP250 core HP60-250 core