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The present paper studies the flexural behaviour of hand manufactured hybrid laminated composites with a hemp natural fibre/polypropylene core and two glass fibres/polypropylene surface layers at each side of the specimen. When compared with full glass fibres reinforced polypropylene laminates, the hybrid composites have economical, ecological and recycling advantages and also specific fatigue strength benefits. Static and fatigue tests were performed in three point bending for both laminates to evaluate flexural strength properties and fatigue behaviour. Fatigue damage was measured in terms of the stiffness loss. Failure sites and mechanisms were evaluated through microscopy studies and a 3D numerical analysis using finite element method.

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This paper concerns fatigue studies of polypropylene/glass-®bre thermoplastic composites produced from a bi-directional woven cloth of co-mingled E-glass ®bres and polypropylene ®bres with a ®bre volume fraction V f of 0.338. The eect of lay-up design and load conditions on fatigue performance were investigated. The S-N curves, the rise in the temperature of the specimens, and the loss of stiness during the tests, are discussed. Fatigue tests were performed in controlled displacement mode and in an imposed stress range. Similar results were obtained for both load conditions. The loss of stiness was used as a damage parameter and related to the rise of temperature. The results show that the damage parameter E present a nearly linear relationship with the rise in temperature. A small deviation was probably caused by the stress release observed in the ®rst period of fatigue life. #

This paper is concerned with a fatigue study of composite adhesive lap joints produced from a bi-directional woven E-glass fibres and polypropylene. The adhesive used was a Bostik 7452 (Rubber & Plastics Grade) ethyl cyanoacrylate type. The effects of layer orientation, lap joint length and water immersion on the fatigue behaviour were studied. The specimens were immersed in water during periods until ninety days for controlled temperatures of 20, 40 and 70 C. The results are presented in the form of curves of stress amplitude versus number of cycles to failure and also in the form of number of cycles to failure against time to exposure in water for fixed stress amplitudes. The fatigue damage and failure mechanisms were analysed and discussed. The joint shows that creep deformation within the temperature range of this study was probably the mainly cause of the dynamic stiffness reduction observed. #

Please cite this article as: Santos, R.A.M., Reis, P.N.B., Santos, M.J., Coelho, C.A.C.P., Effect of distance between impact point and hole position on the impact fatigue strength of composite laminates, Composite Structures (2017), doi: http://dx.doi.org/10. 1016/j.compstruct.2017.02.045 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. In terms of multi-impacts, the damage severity is also very influenced by the distance. For small distances the damage progresses quickly, while three stages can be found for the control samples and for the distance of 20 mm. Effect of distance between impact