Journal of Biological Sciences1727-30481812-5719Asian Network for Scientific Information10.3923/jbs.2013.82.87BahtiarEffendi Tri NugrohoNaresworo SurjokusumoSurjono KarlinasariLina 22013132Bamboo stem’s
cross sectional area is never a perfect circle, but almost ellipse. Each ellipse
shape has a unique value of eccentricity (e) as parameter to denote its circularity.
A perfect circle has a zero value of eccentricity. Conventional calculation
for bamboo flexural properties as designated by ISO 22157-1:2004 resulted an
overestimated or underestimated value compared to the actual value because of
the perfect circle cross sectional assumption. Inappropriate geometrical assumption
of cross sectional area derived inaccurate value of moment of inertia hereafter
affected to the measured flexural properties. Thirty six bamboo stems from 4
species namely Ampel (Bambusa vulgaris Schrad.), Tali (Gigantochloa
apus (Bl.Ex Schult.f) Kurz), Gombong (Gigantochloa verticillata (Willd.)
Munro) and Mayan (Gigantochloa robusta Kurz.) were harvested and it was
found that the eccentricity (e) value of bamboo stem could vary from 0.000 to
0.508. This paper studied the effect of eccentricity to the flexural properties
of bamboo and aimed to create the strength ratio (C_{e}) between actual
elliptical shape and assumed perfect circle shape. It was reported that the
conventional calculation arise an under estimate result if the major axis arranged
horizontally, while overestimate result will be get if the major axis arranged
vertically. So the modulus of rupture (S_{R}) which is calculated by
conventional calculation should be adjusted by the strength ratio of eccentricity
(C_{e}) in order to define more precise value. This study result the
exact relationship between C_{e }value and eccentricity for both conditions.
For simplicity, the graphical sketches were made too.]]>Bahtiar, E.T., N. Nugroho, A. Carolina and A.C. Maulana,2012Dendrocalamus asper (Schult f.) backer ex heyne) by sinusoidal curve fitting on its daily photosynthesis light response.]]>Bressoud, D.M.,1991Correia, A.C.M., G. Boue and J. Laskar,2011Chele, E.S., M.C. Ricardo, P.M. Anac and M.R. Teresad,2012Chung, K.F. and W.K. Yu,2002De Flander, K. and R. Rovers,2009Dransfield, S. and E.A. Widjaja,1995Huang, D.S., A.P. Zhou, H.T. Li, Y. Su and G. Chen,2012Jiang, Z., F. Chen, G. Wang, X. Liu, S.Q. Shi and H.T. Cheng,2012Inoue, A., S. Sakamoto, H. Suga and F. Kitahara,2011Phyllostachys bambusoides, by two-way volume equation.]]>Jennings, G.,1994Kamar, K.A.M., Z.A. Hamid, M.K. Ghani, C. Egbu and M. Arif,2010Kleinhenz, V. and D.J. Midmore,2001Kretschmann, D.E.,2010Lam, P.T.I., E.H.W. Chan, C.K. Chau, C.S. Poon and K.P. Chun,2011Li, H. and S. Shen,2011Nath, A.J., D.C. Franklin, M.J. Lawes, M.C. Das and A.K. Das,2012Nash, W.A.,1998Olson, P. and R. Deguen,2012Sakaray, H.N.V., V.K. Togati and I.V.R. Reddy,2012Schulgasser, K. and A. Witztum,1992Sharma, B., K.A. Harries and K. Ghavami,2013Symonds, J., J.P. Vidosic, H.V. Hawkins and D.D. Dodge,1996Tam, C.M., V.W.Y. Tam and W.S. Tsui,2004Van der Lugt, P., J.G. Vogtlander, J.H. van der Vegte and J.C. Brezet,2012Van der Lugt, P., A.A.J.F. van den Dobbelstee and J.J.A. Janssen,2006Verma, C.S., V.M. Chariar and R. Purohit,2012Vogtlander, J., P. van der Lugt and H. Brezet,2010Wegst, U.G.K.,2011Yu, H.Q., Z.H. Jiang, C.Y. Hse and T.F. Shupe,2008Phyllostachys pubescens).]]>Yu, W.K., K.F. Chung and S.L. Chan,2003Hamid, N.H., O. Sulaiman, A. Mohammad and N.A. Ludin,2012Gigantochloa scortechinii decayed by white and brown rot fungi.]]>Nugroho, N. and E.T. Bahtiar,2012