Design Of Field Portable System To Test Tensile Properties Of Bamboo Roots

At present, soil erosion has become one of the main problems of China’s ecological environment. Long-term studies have shown that, to fasten soil with tree roots are the most economical, effective and environmental-friendly measures to prevent soil erosion. Tensile properties of tree roots should be focused on in research of their mechanics to keep soil; however, the present studies mainly focus on shrubs and herbaceous plants, and few studies pay attention to bamboo roots to keep soil. In order to find out tensile properties of bamboo roots, a large number of bamboo roots should be acquired to do tensile test. Bamboo root is organism, and its mechanical properties has characteristics of life, namely discontinuity, instability, inhomogeneity and anisotrophism, and now the tensile test of bamboo roots is finished in laboratory via universal testing machine, so the collected bamboo roots will get desiccated after being unearthed for a long time, resulting in inaccurate measured tensile mechanical properties. Therefore, this paper designs a portable field test system to measure Tensile properties of bamboo roots. The new system can test the bamboo roots immediately upon they are unearthed, thus, on one hand, the authenticity of measured data is ensured; on the other hand, large quantity of roots can be measured in the field, then important application value can be realized.This test system contains mechanical part and electronic control part, with the premise to ensure field portability and low power consumption. The mechanical part is mainly composed of machine frame, clamping device, transmission system. The mechanical part consists of modular, for convenient disassembly and assembly and easy-to-carry. Special clamping device is designed to clamp roots, and clamping force is adjusted manually. Spiral transmission and bevel gear transmission components make up the transmission system, steering bevel gear helps to move screw up and down. After the design is completed, the3D modeling and finite element analysis are carried out for the mechanical part, and then the final machining scheme is determined. Electronic control part is composed of sensor, power supply, hardware and software of the main control system and peripheral circuit. Tensile force sensor is adopted to measure the value of Tensile force; the angle of encoder movement is converted into displacement. For the main control system, MSP43016ultra low power MCU is adopted as the main controller, and human-computer interaction is realized through keyboard and LCD module, and SD card storage module is designed for real-time storage of the measured data, in order to facilitate the later analysis of experiment data.Finally, the mechanic process part and the electronic control part are debugged, and then the model machine is set up. In operation, firstly, hold ends of the bamboo roots with the two holders, then start test system switch, manually rotate handle to uplift the holder through steering system, and in the lifting process, measure the real-time tension force with the sensor. The encoder read the deformation degree of roots and the result will be displayed on LCD screen and stored in SD card. Then,4kinds of sympodial bamboos are selected for experiment of on-site root anti-tension, and the corresponding data are analyzed to obtain Tensile properties of roots, followed by final conclusions.