Research on Compressed and Dynamic Variation Law of Alfalfa Grass Sheet During Baling Process

Taking High quality alfalfa hay as the research object, we carried out the test at herbage material baling test bench in different cross sections, and we had emplaced two sets of mobile pressure sensing device and three types of displacement sensor, and we also had collected the signals of thickness, compression force and location of grass sheet through virtual instrument acquisition system in the process of compression. Through the data analysis and processing, we obtained compression and dynamic distribution law of grass sheet on alfalfa in the process of baling. Results show that: the compressed area of grass sheet can be divided into three sections in the process of baling - compressed section, stable density section, density recovery section. Noted that there is a process of stress relaxation which is natural formation in stable density section, and the process made the elastic recovery stress of grass sheet decreasing, therefore, it is best to conduct baling in this section, because it helps to improve the stability of the bale shape. The test results provide a theoretical basis for optimization design of herbage material baler and improving the performance stability of the bale