Experimental study on stress transfer of alfalfa during vibration compression

Abstract

To reveal the mechanistic role of vibration in the compression of alfalfa stalk, the stress transfer of alfalfa compression process under the action of vibration force field was evaluated with a self-developed vibration compression test system. The internal stress in the upper layer of the compressed material was gradually transmitted to the lower layer. The stress transfer rate between the upper and lower material varied with the vibration frequency. Within the experimental vibration frequency range, when the frequency was 15 Hz, the stress transfer rate was the smallest. Compared with ordinary compression, the stress transfer rate and maximum pressure during vibration compression were small, but the relaxation density was high, indicating that vibration is beneficial to alfalfa compression. Comprehensive analysis of stress transfer, maximum pressure and relaxation density, when the vibration with vibration amplitude of 0.5 mm and frequency of 15 Hz was introduced, a denser alfalfa block was obtained with less pressure.