Effect of cooling rate on interlaminar fracture energy and shear strength of APC-2 laminates

The effect of cooling rate on some mechanical properties of APC-2/AS4 composite was investigated over the range between 1 and 70° C/min. Preconsolidated unidirectional laminates were reprocessed in a hot platen press at controlled cooling rates. Double Cantilever Beam specimens and End Notch Flexure specimens were used to determine the mode I...

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...

Tensile fracture of notched composite laminates

This report describes the determination of empirical parameters for a fracture model which can be used to predict the uniaxial tensile strength of composite laminates containing notches of various sizes. The parameters required are the characteristic dimension and the unnotched tensile strength of the subject laminate. A data base including...

Rekenprogramma's voor het ontwerpen en dimensioneren van vezelversterkte kunststoffen

This report provides an inventory of computer programs for composite materials which are owned by or known to the members of the NFK-TVK action group. The programs are divided in four groups: general laminate theory; specific laminate problems; general (F.E.) analysis programs; miscellaneous problems. The programs are not discussed in the report...

The static strenght of mechanically fastened carbon-epoxy joints without bending

The mechanical behaviour of mechanically fastened double lap carbon-epoxy joints has been investigated both by experiments (static tests) and by analysis. Several fastener types and joint geometries has been investigated. In the experimental programme the Fibredux 6376/T400H material was used. Two methods to analyze mechanically fastened...

Impact/fatigue performance of a (±45₂, O₄)s type carbon/epoxy laminate

In this report the results of an impact damage and fatigue investigation are discussed. Comparative impact tests have been carried out on a solid (± 45₂,O ₄)s carbon/epoxy base laminate and the same type of laminate covered with outer layers of glass, aramid or carbon fabric. In addition an Aramid Reinforced Aluminium Laminate (ARALL) was...

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...

The use of Arall in fuselage skins

The report starts with a general review of the loading of transport aircraft fuselages and the consequent fuselage skin stresses Taking the F-28 fuselage as an example, the potential weight savings that can be obtained by using ARALL as skin material are assessed. The report ends with conclusions and recommendations

Flight simulation environmental fatigue crack propagation in 2024-T3 and 7475-T761 aluminium

Flight simulation fatigue crack propagation tests on 202U-T3 and 7475-T761 aluminum alloy sheet were carried out using a gust spectrum representative of the load history of an under wing skin in a transport aircraft. The investigation included tests at several design stress levels and in environments of laboratory air and air plus water spray....

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...

The influence of bending-torsional coupling on the buckling load of general orthotropic, midplane symmetric and elastic plates

The influence of bending-torsional coupling on the buckling load of general orthotropic, midplane symmetric and elastic plates has been studied. First this effect has been analysed for the case of infinitely long plate strips, resulting in approximate analytical solutions, which can be presented graphically for the entire range of the elastic...

Residual strength of (0, ±45)s and (±45, 0)s carbon/epoxy laminates

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...

A finite element model to study the buckling behaviour of general orthotropic, midplane symmetric and elastic plates

A finite element model has been developed, which incorporates the bending-torsional coupling effect, as it occurs in general orthotropic, midplane symmetric, elastic plates in order to analyse its influence on the buckling behaviour of such plates. Some results have been compared with known exact and approximate solutions.