Abstract: High kernel damage caused by corn mechanical threshing leads to primary threshing loss and subsequent severe loss of the storage process. A novel method for low kernel damage threshing was inspired by the loosen behavior of hands twisting corn ears, and a ripple-inspired corrugated drum was created to implement the loosening process of this method. Three different types of tests were conducted to quantify the effectiveness of the novel method from different perspectives with five different loosening conditions to prove its effectiveness. The result of the mechanical test has demonstrated loosening reduces the detachment force of corn kernels to corncob from the standpoint of the mechanic. The torque test has proven the proposed pre-threshing loosening method decreases the drag torque of corn threshing by a developed instantaneous acceleration threshing bench from the aspect of loading. The threshing test provides corroborating actual threshing performance evidence that loosened corn ears by the created corrugated drum were effective to reduce kernel damage. The best result was achieved when the compression depth was 10 mm, and detachment force, drag torque, and kernel damage rate substantially decreased compared with the non-loosened group, respectively. The proposed method and implementation show tremendous superiority to reduce kernel damage and also reduce subsequent post-harvest losses and have substantial potential for industrialization.

Key words: Corn threshing')">Corn threshing, Bio-inspired, Corrugated drum, Loosening process, Kernel damage rate