Study On Mechanical Characteristics of Betula platyphylla Root System
Based on the root mechanical characteristics, the arbor root of Betula platyphylla is investigated in North China and the mechanisms of arbor roots systems are analyed systematically. Experiments and studies show that the tensile strength is negatively correlated with root diameter, while a positive correlation is found between single root tensile resistance and root diameter. The experimental results indicate that a power relation exists between single root tensile strength and root diameter in Betula platyphylla. The tensile resistance and tensile strength decreases with increasing gauge length of roots under the same diameter. When the diameter is small, the gap of tensile strength is not obvious at different gauge lengths of the root. The study also reveals that the stress-strain curves of Betula platyphylla root present a straight line relation in the initial root stage after tension. With increasing pulling force after loading over the elastic limit, the stress-strain curves exhibit non-linear elastic characteristics. With increasing gauge length under the same diameter, the residual strain of root decreases and the elastic modulus of the root increases. Two different rates of extension, 400mm/min and 1Omm/min, are used in the experiments. The tensile resistance and tensile strength decrease with increasing rates of extension of roots under the same diameter. When the diameter is small, the gap of tensile strength between different rates of extension of the root is not obvious. However, the difference of the tensile resistance and tensile strength becomes increasingly bigger as the diameter increases.
tensile strength stress-strain curve elastic modulus
CHEN Li-hua ZHOU Shuo JI Xiao-dong ZHANG Chao-bo ZHAO Hong-hua WANG Ping-hua
Key Laboratory of Soil and Water Conservation & Desertification Combat of Ministry of Education, School of Water and Soil Conservation,Beiiing Forest University,Beijing,100083
国际会议
西安
英文
658-662
2010-10-11（万方平台首次上网日期，不代表论文的发表时间）