Spacecraft sustained load fracture control

The opportunities for sustained load fracture control in spacecraft are indicated. Emphasis is given to verification by small-scale laboratory testing.

Flight simulation fatigue crack propagation in metal/carbon-epoxy laminates

Flight simulation fatigue crack propagation tests with gust spectrum loading were carried out on laminates of (i) aluminium alloy 2024-T3/carbon-epoxy, (ii) aluminium alloy 7475-T761/carbon-epoxy and (iii) titanium alloy Ti-6Al-4V/carbon-epoxy with nominal weight savings of 30% and 40% as compared to equivalent 2024-T3 Alclad and 7475-T761...

Review of aeronatical fatigue investigations in the Netherlands during the period march 1977 - february 1979

Paper presented at the 16th ICAP Conference, Brussels, 14 and 15 May 1979.

Environmental fatigue crack propagation in metal/composite laminates

Flight simulation fatigue crack propagation tests with gust spectrum loading were carried out on 2024-T3/carbon-epoxy, 7475-T76l/carbon-epoxy and Ti-6Al-4V/carbon-epoxy laminates with nominal weight savings of -30% as compared to equivalent 2024-T3 panels. The performance of the 2024-T3/carbon-epoxy laminates was much superior to those of the...

Environmental fatigue crack propagation in metal/composite laminates: interim report no. 1

Plight simulation fatigue crack propagation tests with gust spectrum loading were carried out on 2024-T3/carbon-epoxy, 7475-T761/carbon-epoxy and Ti-6Al-4V/carbon-epoxy laminates with nominal weight savings of 30% as compared to equivalent 2024-T3 panels. The performance of the 2024-T3/ carbon-epoxy laminates was much superior to those of the...

The effect of sheet thickness on flight simulation fatigue crack propagation in 2024-T3, 7475-T761 and mill annealed Ti-6A1-4V

Flight simulation fatigue crack propagation tests were carried out on 2024-T3, 7475-T761 and mill annealed Ti-6A1-4V sheet in thicknesses up to 3 nim and representative for traJisport aircraft lower wing skin stiffened panels of end load capacities 1.5 and 3 MN/m. There was a significant effect of sheet thickness on crack propagation. Thinner...

Flight simulation fatigue crack propagation evaluation of candidate lower wing skin materials with particular consideration of spectrum truncation

Flight simulation fatigu-e crack propagation tests were carried out on 2024-T3, 7475-T761 and mill annealed Ti-6A1-4V sheet in thicknesses up to 3 miri and representative for transport aircraft lower wing skin stiffened panels of end load capacities 1.5 and 3 MN/m. The performance of 2024-T3 was much superior, owing mainly to greater retardation...

Residual strength data of riveted panels with different stiffener configurations

Residual strength tests were carried out on center-cracked panels with a 2024-T3 or 7075-T6 skin and provided with eccentric stiffeners of practical design. The stiffeners were riveted to the skin. The material of the stiffeners was 7075-T6. In some cases the stiffeners were combined with Ti-alloy crack stoppers. On the basis of the test results...

Rate effects on residual strength of flawed structures and materials

The literature is reviewed with respect to: - tests conducted to investigate crack re-initiation under dynamic load and arrest of a running crack - metallurgical sources of rate effects - available data for aerospace engineering materials - mechanical sources of rate effects, i.e. dynamic crack tip stresses and kinetic energy effects Conclusions...