PSI - Issue 60

Rohan Nair et al. / Procedia Structural Integrity 60 (2024) 93–114

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Rohan Nair / StructuralIntegrity Procedia 00 (2023) 000–000

cycles is based on NASA Technical standard -NASA-STD-5012 [14] where multiplication factor of 4 is applied to the no. of Proof pressure testing allowed in a life cycle of a Pressure vessel till flight. As part of the testing schemes, the test article has to initially undergo an acceptance test and therefore has been subjected to a proof pressure test at a peak pressure of 5.8+0.2bar (g).

3.1.1.

Analytical/numerical method for strain prediction:

Finite element analysis was carried out using ANSYS software. Test article was idealized as shell element and multi-linear properties were used for analysis. A geometric and material non-linear analysis was carried out by applying internal pressure on the test article and same was increased till the abort of analysis. Abort value of pressure was taken as predicted burst pressure. For strain predictions, directional strains were extracted at strain gauge locations at various pressures. Instrumentation & test: A set of instrumentation scheme is planned on the test article to record data during pressure testing. The instruments used along with its details include 38 strain gauges along with pressure gauges, pressure transducers, acoustic emission (AE) and data acquisition system. The strain gauges used were bi-element type of 90 0 orientations which gives strain results in two mutually perpendicular directions. The strain gauges used for proof pressure test and cyclic pressure tests had a maximum range of 30000 µs with a least count of 1 µs. The strain gauge and AE sensors location marking on the test article is shown in Fig. 9 & Fig. 10 respectively. The strain gauge locations are shown in table-3.

3.2.

Table 3: Strain gauge locations for proof pressure test, cyclic MEOP and cyclic proof pressure test Strain gauge locations Locations As welded RW 1 RW 2

RW (NC)

Total

2Nos. (S29,S30)

4Nos. (S14,S15,S18,S19) 4Nos. (S10,S11,S22,S23)

4Nos. (S16,S17,S20,S21) 4Nos. (S12,S13,S24,S25)

LS_Inner

10

LS_Outer

8

CS_03 CS_04

1No. (S36)

1 4

2Nos. (S8, S9)

2Nos. (S2,S3)

2Nos. (S34,S35) 1No. (S32)

CS_05

1No. (S33)

3

CS_06

2Nos. (S6,S7)

2Nos. (S4,S5)

5 2

Ø99 mm

2Nos. (S26,S27)

Adaptor CS

1No. (S28)

Ø145 mm

1

Shell (Parent Material)

4Nos. (S1,S31,S37,S38)

4

Total

38