Mechanical properties of the rachis from macaw palm bunches

Numerical implementation methods such as the finite element method can be used in machine design to study the dynamic behavior of the plant. Input parameters for using the finite element method should be set based on the geometrical, physical and mechanical system under study. Thus, the aim of this study was to determine the mechanical properties of the rachis of macaw palm in the green maturation stage at an age of 180 days and at fruit maturation. The water content was calculated using the oven method of 105 ± 3°C for 24 hours. The modulus of elasticity for the rachis was determined by means of mechanical compression testing. The Poisson's ratios were determined from the results of the longitudinal and transverse deformation of rachis test bodies. The shear tests were performed in two scenarios. In the first one, a blade was used without a tensioner, and in the second scenario, a blade was fixed with a tensioner, characterized by a chamfer at 45°. It was concluded that the modulus of elasticity of macaw palm rachis in the green maturity stage was higher than the values for the mature stage of ripeness.

Keywords:
Acrocomia aculeate; modulus of elasticity; Poisson's ratio; shear test

Authorship

Zenil Ricardo Cunha Rodrigues de Oliveira

Departamento de Engenharia Agrícola, Universidade Federal de Viçosa, Av. P.H. Rolfs, s/n, Campus Universitário, 36570-900, Viçosa, Minas Gerais, Brazil.Universidade Federal de ViçosaBrazilViçosa, Minas Gerais, BrazilDepartamento de Engenharia Agrícola, Universidade Federal de Viçosa, Av. P.H. Rolfs, s/n, Campus Universitário, 36570-900, Viçosa, Minas Gerais, Brazil.

Fábio Lúcio Santos ^**Author for correspondence. E-mail: fabio.santos@deg.ufla.br

Departamento de Engenharia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil. Universidade Federal de LavrasBrazilLavras, Minas Gerais, BrazilDepartamento de Engenharia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil.

Domingos Sarvio Magalhães Valente

Francisco de Assis de Carvalho Pinto

Nara Silveira Velloso

*Author for correspondence. E-mail: fabio.santos@deg.ufla.br

SCIMAGO INSTITUTIONS RANKINGS

Figures | Tables

Figures (7)
Tables (10)

Sites	Average water content (%w.b.)
Sites	Immature	Mature
BGP 12	78.20 aA	80.55 aA
BGP 13	76.34 aA	78.10 abA
BGP 31	77.84 aA	72.31 bB
BGP 53	82.72 aA	81.30 aA

Stages of maturation	Poisson's ratio
Immature	0.29 ± 0.14 a
Mature	0.31 ± 0.14 a

Cutting blade	Shear stress (MPa)
Without tensioner	2.79 ± 0.54 a
With tensioner	0.90 ± 0.54 b

Maturation stages	Modulus of elasticity (MPa)
Immature	51.97 ± 9.18 a
Mature	37.93 ± 9.18 b

Stages of maturation	Compressive strength (MPa)
Immature	6.81 ± 1.03 a
Mature	3.34 ± 1.03 b

Sites	Poisson's ratio
BGP 12	0.32 ± 0.27 a
BGP 13	0.33 ± 0.27 a
BGP 31	0.35 ± 0.27 a
BGP 53	0.22 ± 0.27 a

Sites	Shear stress (MPa)
Sites	Without tensioner	With tensioner
BGP 12	2.78 ± 1.62 a	0.86 ± 3.09 a
BGP 13	2.85 ± 1.62 a	0.92 ± 3.09 a
BGP 31	2.36 ± 1.62 a	0.96 ± 3.09 a
BGP 53	3.17 ± 1.62 a	0.87 ± 3.09 a

Sites	Modulus of elasticity (MPa)
BGP 12	39.83 ± 18.23 a
BGP 13	39.40 ± 18.23 a
BGP 31	54.72 ± 18.23 a
BGP 53	45.85 ± 18.23 a

Sites	Compressive strength (MPa)
BGP 12	4.86 ± 2.88 a
BGP 13	4.54 ± 2.88 a
BGP 31	5.98 ± 2.88 a
BGP 53	4.93 ± 2.88 a