Effects of modeling difference on load calculation of jacket-type offshore wind turbine

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A study on the effect of different modeling parameters on the dynamic response of a jacket-type offshore wind turbine in the Korean Southwest Sea

As a country mostly surrounded by water, Korea has good potential for offshore wind energy utilization. With offshore wind turbines growing larger and with increasing water depth, jacket structures are attracting increased attention because they appear to be cost-effective, but they are still at an early stage of development for use in the offshore wind industry. This paper aims to design a jacket structure to support a 5 MW wind turbine in 33 m deep water for a Korean offshore demonstration project and to investigate the effects of different modeling parameters (including joint can, overlap, flooding of the member, marine growth and mass of the transition piece) on the dynamic response of an offshore wind turbine with a jacket substructure. For this purpose, modal analysis and aero-servo-hydro-elastic simulation with varying modeling parameters are performed under Korean environmental conditions. The results show that joint can, overlap and marine growth strongly affect the dynamic response and there is a small effect on the natural frequencies of the designed structure. Choosing the appropriate transition piece mass may reduce the extreme loads in the members. This study provides applicable knowledge of the utilization of large-scale offshore wind turbines for intermediate water depths in Korea. (C) 2013 Elsevier Ltd. All rights reserved.X111715sciescopu

Biomimetic microfingerprints for anti-counterfeiting strategies

An unclonable, fingerprint-mimicking anti-counterfeiting strategy is presented that encrypts polymeric particles with randomly generated silica film wrinkles. The generated wrinkle codes are as highly unique as human fingerprints and are technically irreproducible. Superior to previous physical unclonable functions, codes are tunable on demand and generable on various geometries. Reliable authentication of real-world products that have these microfingerprints is demonstrated using optical decoding methods. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim159621sciescopu