No abstract

The wind energy has been recognised as one of the rising sustainable energies in the world. The wind turbines are subjected to high aerodynamic loads and they cause vibrations due to the wake formation. The magnitude of the applied loads has significant effects on the crack propagation. The fatigue loads have been identified as one of the key sources of damage, with delamination as the main cause for the failure of the turbine blades. The article presents a review of fatigue damages that have been experienced in the wind turbine blades, and factors that are influenced due to the fatigue loads are discussed. The causes and effects of the fatigue loads have been highlighted, and the ways for preventing the fatigue damage by improving the design lifetime are mainly concentrated in review. The overall review gives an idea for determining and reducing the crack growth in wind turbine blades.

Purpose Additive manufacturing has paved a way for geometrical freedom and mass customization of new and innovative products. However, it has a few limitations in printing complex geometries and sizes. The purpose of this paper is three-dimensional printing of metal parts using selective laser melting (SLM) has several intricacies. Design/methodology/approach To test the capabilities of SLM, the complex geometries of varying sizes, orientations, shapes such as square and cylindrical features, thin wall structures and holes were checked for dimensional accuracy and surface roughness. Findings The outcome of the study represents the capabilities of SLM and provide insight for solving the technological issues and processing constraint in the manufacture of metal parts from aluminum alloy. The analysis has proven that there is significant accuracy in dimension for large features in comparison with smaller one. The dimensional reproducibility was determined with the aid of an optical measuring system and the range of errors were calculated. These results show that the dimensional accuracy of the features in the printed part was within acceptable tolerance limits. This paper also investigated the significant contributing factors influencing printing of two and three-dimensional surface roughness based on the result of surface profilometer and it was observed that the surface was smoothened with the presence of overhangs and supports. Originality/value The ability of SLM to fabricate conformer cooling channels to support mould fabrication was tested. From the experimental result, it was observed that the quality of printing of conformal cooling channels depended on the diameter of channels with larger distortions in the channel having smaller diameter. The innovative aspect of the work was the study of build orientation combined with the investigated material.

The focus of this study is contemplating the resin flow behaviour (dictating permeability) in a sisal based natural fibre mat compared to a glass fibre mat. This mainly deploys fibre reinforced plastics subjected to a vacuum infusion process. The outcome of this research emphasizes the wetting mechanism and fibre network of sisal mats, which significantly reduces the flow characteristics. In addition, it is observed that the swelling phenomenon had an insignificant or minimal influence on the permeability of the sisal fibre mat. However, employment of bio-based resin provides a considerable change in the swelling phenomenon. Hence, this factor is important to consider in permeability studies to attain higher accuracy.