common bulkhead tank shown in Figure Q.3. The “Configuration 1”
consists of aluminium skins with an aramid honeycomb core, whilst
“Configuration 2” is made of CFRP skins and a PMI foam core. The
properties of all materials are listed in Table Q.3a.
The sandwich structure has both mechanical and thermal
functionalities. It separates liquid hydrogen from liquid oxygen
while maintaining a temperature difference of about 70°C. The
sandwich also needs to bear the pressure difference between two
tanks and withstand inertia loads during launch. The shape of the
two sandwich configurations in terms of curvature, diameter and
total thickness is exactly the same (see Table Q.3b).
- Two Sandwich Configurations Are Proposed For The Design Of A Common Bulkhead Tank Shown In Figure Q 3 The Configuratio 1 (241.65 KiB) Viewed 7 times
configurations for:
(i) Mass.
(ii) Flexural rigidity.
(iii) Failure under face fracture/yield (for simplicity,
consider equivalent fully clamp, flat beam with the length of 5.5 m
under uniform pressure).
(iv) Failure under shear (for simplicity, consider equivalent
fully clamp, flat beam with the length of 5.5 m under uniform
pressure).
(v) Thermal performance (consider through-thickness thermal
conduction).
Aluminium 2840 alloy PMI Foam 110 Honeycomb 31 CFRP 1500 Table Q.3b skin tskin material Aluminium alloy tcore tskin Figure Q.3. Table Q.3a Density Compressive Poisson's Compressive (kg/m³) Modulus ratio Strength (MPa) (GPa) 73.1 0.33 483 0.18 0.29 3.69 0.076 0.25 0.9 65 0.03 585 Configuration 1 thickness material thickness 1 mm Ares I Upper Stage Common Bulkhead LH2 Tank LO2 Tank Ares I Upper Stage 5.5m diameter Pressurized Structure Shear Shear Linear Modulus Strength Expansion (GPa) (MPa) Coefficient 28 290 0.07 2.4 0.029 0.65 2.4 22.1 material CFRP core Honeycomb 28 mm skin Ares I Specif ic Heat (με/Κ) J/g.K 20.8 0.88 50.0 2.00 10 0.38 1 1.13 Configuration 2 thickness 1 mm material PMI Foam core Thermal Conductivity W/m.K 154 0.043 0.06 0.87 thickness 28 mm