Colloquium: Jonas Appels (ASM)

In developing Type V hydrogen tanks, the key design criterion is maintaining tightness under cryogenic conditions. Anomalies in the laminate can cause microcracks that compromise this. This study examined how resin flow, caused by an expanding mould during curing, creates a gradient in the local fibre volume fraction (FVF) across the laminate. The impact of resin system selection, autoclave cycle parameters, mandrel material, and fibre tension on the FVF gradient was investigated. Cylindrical specimens were manufactured with a piezoelectric sensor measuring contact pressure at the mandrel-laminate interface during the autoclave cycle as an indicator of resin flow and FVF spread. The study found that the resin's viscosity profile and gelation characteristics had the most substantial impact on the maximum FVF spread. These findings provide valuable insights for minimising FVF gradients in the design of carbon fibre-reinforced polymer (CFRP) hydrogen tanks.

Supervisor: Dr.B. Atli-Veltin, Philipp Sämann