PSI - Issue 18

Vladimír Chmelko et al. / Procedia Structural Integrity 18 (2019) 600–607 Chmelko, V., Berta, I./ Structural Integrity Procedia 00 (2019) 000 – 000

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bilinear material model (Fig. 4). The material exhibited orthotropic behaviour as a result of semi-product manufacturing technology for the experimental model. Its tensile strength was about 10% higher in the tangential direction than in the axial direction, which was considered in the simulation.

Fig. 4 The material model used in numerical simulation by FEM.

The burst pressure was determined experimentally for two specimens of a pressure vessel made by fine turning from an original 150x8 pipe at the internal diameter of 143mm and a wall thickness of 4mm with welded toroid bottoms (Fig. 5). The oil pressure required to achieve the destruction of the pressure vessel specimens was obtained by means of an electrohydraulic pulsator EDYZ 6. In the machine frame, a straight-line 80/50/125 hydraulic motor was clamped with a piston surface of 5026.5 mm 2 , which converted the force exerted by the pulsator into the oil pressure (Fig. 5) . The results of the experimentally obtained destructive pressures together with the results of the analytical relationships for the 143mm internal diameter and 4mm wall thicknesses and the results of the numerical models using FEM are given in Tab1.

Tab. 1 Results of the burst pressures.

Experimental p exp [MPa]

Numerical p num1 H-M-H [MPa]

Numerical p num2 Tresca [MPa]

Analytical p an1 HMH [MPa]

Analytical p an2 Tresca [MPa]

Infinity cylindical vessel Specimens of closed pipe

37,0

32,0

36,9

32,1

38,1 ; 38,3

36,8

32,2

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