Papers by Keyword: Pullout Force

Abstract: Peanut root of crop lands in Menglianggu watershed in the upper reaches of Yi River were classified into different diameter classes by root diameter. The results show that (1) the relationship between force of pullout or breaking and root diameter is approximately linearity, and more significant linear for the latter; (2) Laboratory tests confirm the presence of a threshold or range of root diameter. When the diameter within the range (1.80-3.01mm), both root breaking and pullout occurred; when the diameter above 3.01mm, all roots broke under applied stress. While below 1.80mm, only roots were pulled out under applied stress. Root-soil resistance characteristic and root reinforcement effect were analyzed for different root classes: (3) pull out force of root-soil resistance is stronger than that of single root of the same root classes with the range from 6.03% to 39.39%.

Abstract: In this paper, the experimental study on the self-tapping screw’s pullout resistance in the wood structure was conducted. Domestic ordinary screws were used together with imported or domestic wood to fabricate 6 screw connection specimens in wooden walls. Then monotonic loading tests were conducted and it can be concluded that, the common round screw connection strength mainly depends on the failure mode, the lack of cooperation effect significantly influences the strength of screw connections, and the dispersion of screw connection stiffness is high. So, to obtain formulae for the self-tapping screw connection strength and stiffness by further experimental study will be very necessary.

Abstract: Pullout force of grouting soil nailing is a key to support. This test revealed that limit pullout force of soil nailing increased with the time. The timeliness function was asked for by Origin software. It's the cause for many failure accidents in soil nailing support engineering. But it was often neglected in engineering design and construction.

Abstract: Bone possesses excellent mechanical properties, which are closely related to its favorable microstructures optimized by nature through many centuries. In this work, a scanning electron microscope (SEM) was used to observe the microstructures of a cannon bone. It showed that the bone is a kind of bioceramic composite consisting of hydroxyapatite layers and collagen protein matrix. The hydroxyapatite layers are composed of long and thin hydroxyapatite sheets. The hydroxyapatite sheets in different hydroxyapatite layers distribute along different orientations, which composes a kind of cross microstructure. The maximum pullout force of the cross microstructure was investigated and compared with that of the 0° microstructure with their representative models. The result indicated that the maximum pullout force of the cross microstructure is markedly larger than that of the 0° microstructure.