Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Design and Static Analysis of a High-performance Float Arm of Wave Energy Converter
Guanghua He1, 2, 3, Chaogang Liu1, 3, Hai Yu2*, Zhigang Zhang1, Zhengxiao Luan1, Yang He1
1. School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, China
2. Weihai Science and Technology Innovation Development Center, Weihai, Shandong, China
3. Shandong Institute of Shipbuilding Technology, Weihai, Shandong, China

wave energy has an optimistic development prospect. It is estimatedthat the potential worldwide wave power resource is 2.0 TW (Drew etal., 2016).

ABSTRACT
Based on the engineering background of the point-absorber wave
energy converter (WEC), a variable-section float arm of the WEC isproposed. To obtain the basic mechanical properties of the structure
under the wave load, the overlapping-grid technology is used to carryout the hydrodynamic analysis of the float by the commercial software
STAR-CCM+, and the stress analyses of a constant-section float arm
and a variable-section float arm are carried out by another commercial
software ABAQUS. The results show that: both the stress peaks of theconstant-section float arm and the variable-section float arm appear at
the connection between the float arm and the base, where stressconcentration is easy to happen. The float arm should be reinforced
here in the design and manufacture. The stress peak and deflection peakof the variable-section float arm proposed in the present study are lower
than those of the constant-section float arm. The high-stress area of thevariable-section float arm is smaller than that of the constant-section
float arm, and the stress distribution is effectively improved. Comparedwith the constant-section float arm, the variable-section float arm has
better bending resistance and reliability, and can adapt to a more
complex marine environment.

Wave energy has long been considered as one of the most promising
renewable energy sources, which is not only wide in the sea, but also
more reliable than most renewable energy sources. The energy densityof wave energy is about 5 times that of wind energy and 15 times thatof solar energy (Liu et al., 2015). The total amount of wave energy
storage is much greater than that of wind energy, and there is only asmall energy loss during the propagation process. Wave power at agiven site is available up to 90 percent of the time, while solar andwind availability tends to be available 20-30 percent of the time (Pelcand Fujita, 2002).
According to wave-power generation technologies, wave energy
converter (WEC) devices can be classified as point absorbers(Engström et al., 2013; Sinha et al., 2016; He et al., 2022), oscillatingwater columns (Crowley et al., 2014; Henriques et al., 2016; Gomes etal., 2020), overtopping systems (Hu et al., 2000; Kofoed et al., 2006;
Vicinanza et al., 2012), bottom-hinged systems (Salter, 1992; Henry etal., 2010; Behzad and Panahi, 2017), and raft-type devices (Michailidesand Angelides, 2012; Zheng et al., 2016; Shi et al., 2021). The pointabsorber WECs have good application prospects because of their highenergy conversion efficiency, small impact on the marine environment,and various structural forms. Yu and Li (2011) investigated the detailsof the flow around the absorber and its nonlinear interaction with waves,and the power absorption efficiency of the two-body floating wave
absorber in waves with a constant value spring-damper system. Lyu etal. (2016) designed an oscillating-buoy WEC based on hydraulictransmission and validated the rationality of the wave power generating
system by AMESim software. Luan et al. (2019) solved the resonancecondition of a cylindrical float by both numerical and analyticalmethods and investigated the hydrodynamic performance of this float
without damping constant under different wave conditions. Ji et al.
(2021) investigated the effects of radius, draft, and vertical mass
distribution of an oscillating body on the hydrodynamic performance

KEY WORDS: Wave energy converter; variable-section float arm;
numerical simulation; stress; strength check.

INTRODUCTION
In recent years, the rapid development of population and economy has
brought benefits to human beings, but also caused many problems.
Among them, the problems of excessive resource consumption
increasingly depleted energy and environmental pollution can not beignored. Therefore, renewable energy is actively developed and utilized
all over the world, among which ocean energy is an inexhaustible andclean new energy. China has a long coastline, wide marine land, andrich marine resources. The power load especially in the eastern coastal
areas can create conditions for the development and utilization of largescale ocean energy (Wang et al., 2014). As a kind of ocean energy,519