基于机械导纳测试的山核桃树动态特性实验与分析

he dynamic response experiment was conducted on the 8-year-old dwarf Chinese hickory trees at different growth stage. According to the structure of the specimens, the main transmission paths were defined as from the excitation point to the targeted fruiting branches, and the dynamic response and the resonance frequencies of the dwarf Chinese hickory trees were obtained based on the mechanical admittance analysis. Obtained results showed that the resonance frequencies below 20Hz were very close for the tested leader limbs, and those offshoots without secondary crotch had the resonance frequencies very close to those of the leader limb. The effect of leaves was more than that of fruit on the resonance frequencies of the Chinese hickory tree. Besides, the wood diameter ratio at the crotches, the crotch angles between branches, and the chain angles along the branch chains were discussed as the influence factors on the vibration transmission. Analysis result revealed the vibration transmission pattern was related to the crotch angle or chain angle, diameter ratio and resonance frequencies. Leaves and fruit had great influence on the dynamic characteristics of the dwarf Chinese hickory tree.