Analysis of deflection and dynamic plant characteristics of Cyperus malaccensis Lam

Mana Shioya,Arata Myoga,Atsuya Kitagawa,Yukihisa Tokunaga,Hiroaki Hayashi,Yasuo Kogo,Hiroaki Shimada,Shin-Ichi Satake

doi:10.1080/1343943x.2019.1588075

Mana Shioya, Arata Myoga + Show 6 more

Open Access

https://doi.org/10.1080/1343943x.2019.1588075

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Abstract

ABSTRACT In this study, flexural rigidity, natural frequency, and damping coefficient of Cyperus malaccensis Lam. with long stems were measured for application for fluid–structure interaction simulation in a field. Numerical solutions of deflection and natural frequency were calculated by ANSYS with finite element method (FEM). The triangular cross-section shape of C. malaccensis stem has a big neighbourhood of the root and the cross-section has taper structure to become small towards tip direction. Two numerical simulation models for FEM have Model A with a triangular prism shape and Model B with a truncated trigonal pyramidal shape to evaluate the effects of stem tapering. Because of large C. malaccensis stem deflection, an equation for nonlinear deflection was introduced to solve a problem regarding flexural rigidity. Natural frequencies of the stem were estimated using amplitude ratio during stem swinging by forced vibration, captured using a high-speed camera. The Model B corresponded with the measurement, and the results suggested that the stem characteristics were affected by cross-section shape. Damping coefficient was calculated using free vibration response, which was consistent with the analytical solution and numerical data calculated using measured characteristics. Abbreviations C. malaccensis: Cyperus malaccensis; FEM: finite element method; GIAHS: Globally Important Agricultural Heritage System

Highlights

Cyperus malaccensis Lam. (Order, Cyperales; Family, Cyperaceae) is a sedge, commonly called the Chair Maker or Chinese Matgrass
After the Kunisaki Peninsula was registered as a Globally Important Agricultural Heritage System (GIAHS) as the ‘Kunisaki Peninsula Usa Integrated Forestry, Agriculture and Fisheries System’ by the Food and Agricultural Organization of the United Nations at 2013, C. malaccensis has again come under the global attention as an important industrial fiber crop (Hayashi, 2014)
When the models used in this study had the same L and EI, the deflection of Model A became larger than that of the measurement and Model B because the deflection at the top was maximum when the model was flat and not tapered

Summary

Introduction

Cyperus malaccensis Lam. (Order, Cyperales; Family, Cyperaceae) is a sedge, commonly called the Chair Maker or Chinese Matgrass. (Order, Cyperales; Family, Cyperaceae) is a sedge, commonly called the Chair Maker or Chinese Matgrass. This plant serves as the raw material for making tatami mats and is cultivated mainly in Japan and China (Hayashi, 2014). The characteristics of C. malaccensis are its sharp, triangular and long stem, absence of nodes, and 2–3 leaves at the stem tip (Karamchand et al, 2009). It is harvested when it reaches a height of ~1.5 m after its stem has been cut several times to ensure uniform stem thickness

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