End-of-life wood quality of mooring poles

A damage tolerance study conducted with structure relevant specimens

A preliminary investigation is reported of the development of a Structure Relevant (SR-) specimen, which maintains the essential features of a stiffened panel configuration, in order to study damage growth behavior at limited cost. Several SR-specimens were fabricated, damage was applied, either through impacts or by the insertion of artificial...

Fatigue and residual strength behaviour of ARALL3 panels with bonded-on doublers

Residual strength tests were performed on ARALL panels consisting of ARALL3 (3/2) laminates with bonded-on doublers. In particular, the effect of the doubler geometry (shape and thickness) on the residual strength was investigated. Prior to residual strength testing all panels were fatigue loaded to create a realistic type of damage, i.e. cracks...

Bulging of fatigue cracks in a pressurized aircraft fuselage

Bulging of fatigue cracks in a pressurized aircraft fuselage

Delamination growth in improved carbon composites under constant amplitude fatigue loading

Constant amplitude tension-compression fatigue tests were performed on notched (± 45, 02, 90, 02)s coupon specimens of the composite systems T300/F593, T400H/6376, T800H//5245C and IM6/APC-2. Delamination damage growth as a function of the number of fatigue cycles was determined using the ultrasonic C-scan technique. Considering the resistance...

Residual strength characteristics of composite reinforced stiffened panels

Residual strength properties of carbon/epoxy composite material

Fatigue tests on unidirectional Ca/ep composite material have been performed to investigate whether previous fatigue loading did influence the residual static strength. Residual strength tests were carried out on (0, ± 45)2s and (± 45)2s laminates, while for the (O, ± 45)2s laminate the influence of previous tensile fatigue loading on the...

Residual strength of the aluminium alloy 7475-T76 at low temperatures

Residual strength tests have heen performed, on 300 mm wide centrecracked panels of various thicknesses, at room temperature and at -50 C. During the tests, stable crack growth was filmed and recorded with the electric potential method. Fracture toughness was determined using the method of Feddersen.

Supplementary residual strength investigation of the aluminium alloy 7475-T76

Some residual strength tests have been performed on 610 mm wide centre-cracked panels at a temperature of -50 C, in order to examine whether equal Ke values are obtained as for 300 mm wide panels, tested at -50°C. This work is a continuation of the residual strength investigation reported in NLR TR 76103 and NLR TR 75168.