Effect of applied force direction on bending behavior of boxwood stalk

The bending behavior analysis of boxwood stalk, including bending force, bending strength, and Young’s modulus, were carried out at different loading rates and internode positions as a function of applied force direction to design a new hedge trimmer machine. Given that the cross-section of the stalk is oval, the stalk specimens were examined in a quasi-static process at four loading rates of ۵, ۱۰, ۱۵, and ۲۰ mm min-۱, three internode positions of fifth, tenth, and fifteenth, and two directions of the applied force of the oval major (x-direction) and minor (y-direction) diameters. The results showed that the loading rate of ۲۰ mm min-۱ had ۲۰–۳۰% and ۱۵–۲۰% lower values for the bending force and bending strength than the loading rate of ۵ mm min-۱ for all stalk regions and both directions of applied force. Also, the loading rate of ۲۰ mm min-۱ had ۵۰–۷۰% and ۳۵–۴۰% lower values for Young’s modulus than the loading rate of ۵ mm min-۱ in the x and y directions of applied force, respectively, for all stalk regions. The fifth internode had ۴۰–۴۸% and ۳۵–۳۷% lower values for bending force and bending strength than that of the fifteenth internode position for all loading rates and both applying force directions. Also, the fifteenth internode position had ۵۰–۸۰% and ۴۰–۶۰% lower values for Young’s modulus than the fifth internode position in the x and y directions of applied force, respectively, for all stalk regions.

کلیدواژه ها:

bending stress ، major and minor diameter ، Young’s modulus