Measurement of compressive and shear resistance stresses in common paddy varieties

Kahrizi, Vahid and Askari Asli-Ardeh, Ezzatollah and Abbaspour Gilandeh, Yousef (2010) Measurement of compressive and shear resistance stresses in common paddy varieties. Other thesis, University of Mohaghegh Ardabili.

Text کهریزی وحيد.pdf Download (934kB)

Abstract

Rice is among the oldest cereals, constituting the basic food for the large number of our country population. This crop is influenced by a large number of static and dynamic forces during harvest, transport and other stages of the process. Mechanical properties of paddy rice affects greatly on the milling process. Grain moisture content is an effective factor on the mechanical properties of the grain. During grain drying process, increasing grain strength decreases the grain waste. At this study, compressive strength, maximum normal and shear stress of two paddy rice varieties (Hashemi and Alikazemi), at two levels of grain moisture content (8 and 12% w.b.), under different angles between applied force and straight posed grain on surface (15, 30, 45, 60, 75, and 90 degrees) and two grain positions on tilted surface (at straight of tilted surface and perpendicular to first straight), were determined and analyzed. The results of variance analysis showed that the effects of grain moisture content and angle between applied force and straight of grain posed surface and also interactions of these factors on normal and shear stresses, were significant. Effect of grain posed position on tilted surface was significant on normal and shear stresses. Decreasing of grain moisture content from 12 to 8% w.b., the mean of grain normal and shear stresses Increases from 8.471 to 14.050 N/mm2 and 14.989 to 23.763 N/mm2, respectively. Increasing of angle between applied force straight and grain posed surface straight from 15 to 90 degree, shear stress was increases linearly and grain normal stress for the angle of 45 degree has becomes maximum.

Actions (login required)

View Item