Journal of Researches in Mechanics of Agricultural Machinery

Journal of Researches in Mechanics of Agricultural Machinery

Mechanical properties of healthy and unhealthy woods of walnut and almond trees

Document Type : Original Article

Author
Mechanical Engineering of Biosystems
Abstract
Today, horticultural crops are often harvested mechanized in developed countries, so to 
design devices such as shakers used for harvesting, and we must have the necessary 
information about the wood of the branches and trunks of trees so that we can harvest with 
minimal damage. Therefore, the mechanical properties of almond and walnut wood, including 
shear modulus, yield stress, fracture stress, toughness, and germination modulus, were 
investigated to distinguish these values between healthy and unhealthy wood and the effects 
of factors such as storage time, moisture, diameter, cutting speed and condition of wood of 
two different wood products (almond and walnut) were investigated, and the results were 
compared. The condition of the wood was in two types, healthy, which did not have any 
worm corrosion, and unhealthy, which the Zeozera Pyrina damaged. The results of the 
analysis of variance of the main factors and their interaction in almond wood showed that the 
main factors of cutting speed and healthy and unhealthy and the interaction effects of two 
factors of cutting speed and year (shelf life), cutting speed and healthy and unhealthy, cutting 
speed and moisture. They had a significant effect on the 5% probability level. In walnut 
wood, the effect of the main factor of moisture and the interaction of healthy and unhealthy 
and humidity were significant at 5% probability. With increasing cutting speed in almond 
wood, the shear modulus increased from 28 to 32 and then to 39 MPa, respectively, the stress 
at the yield point increased from 26 to 28 and then to 45 MPa, and the stress at the breaking 
point increased from 20 to 32 MPa. It had more moisture and was more flexible. It was seen 
more than wood, which had less moisture. Also, these values in walnut wood with higher 
moisture decreased more than in wood with less moisture. 
Keywords