Nonlinear analysis of the crashworthy component of an eagle wave energy converter in rotating-collision. (1st October 2016)

• Record Type: Journal Article
• Authors: Chen, Aiju; You, Yage; Sheng, Songwei; Lin, Hongjun; Ye, Yin; Huang, Shuo
• Is Part Of: Ocean engineering. Volume 125(2016)
• Page Start: 285
• Page End: 294
• Publication Date: 2016-10-01
• Subjects: Wave energy converter -- Non-linear finite element analysis -- Rotating collision -- Collision mechanics -- Impact force; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2016.08.025
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: The Eagle wave energy converter (WEC) is novel device and has high power generation efficiency demonstrated by the small-scale model in the tank tests. During the sea trials of 10 kW full-scale prototype performed from 2012 to 2014, a design problem occurred that the crashworthy component (namely End Beam) was crashed up by the rotor. In order to investigate the damage mechanism of End Beam and improve the design of the Eagle WEC, an impact analysis was conducted utilizing ANSYS/LS-DYNA. In the simulation, structures were modeled as full-scale parameters and assumed to be elastic–plastic. Meanwhile, the bottoms of End Beam were presumed to be standstill. Moreover, the influences of water surrounding the WEC structures were considered using added mass method. Through the simulation, the stress and strain distributions, collision force and the energy absorption of the system were obtained. The results fit well with the actual damage situation. Furthermore, three improvement schemes were proposed including enhancing the structure of End Beam, increasing the upward angle of the rotor and adding energy accumulator. The simulation results demonstrated that the third method can effectively absorb the kinetic energy of the rotor and prevent the WEC from destruction in the rough sea states. Highlights: The structural damage of the floating Eagle wave energy converter (WEC) caused by rotating collision is investigated. Relationship between the gravitational potential energy and the crashworthy capacity is studied by finite element method. The enhanced structure reduces the crashworthiness for the limited deformation leading to high local stress concentration. Adding rotation angle will greatly reduce the rotor's kinetic energy and improve the crashworthiness in the small velocity. By adding an energy accumulator with proper volume, the Eagle WEC can avoid destruction in the rough sea states.