Finite element analysis on damage of rice kernel impacting on spike tooth

A computer-aided design model of a rice kernel comprising three layered ellipsoids was established. HyperMesh software was used to partition mesh cells and set material and contact parameters for each cell and thus construct a finite element model for analysis. Using LS-DYNA software, the impact process between the spike-tooth and the rice kernel was simulated and analyzed. The simulation showed that the contact zone between the spike-tooth and the rice kernel was elliptic, and the compressive stress was a maximum at the center of the contact zone. The von Mises stress value of rice seed skin and endosperm gradually increased with the increase of impact velocity. The critical damage velocity for the kernel corresponding to the endosperm critical von Mises stress was 24.2 m/s, while the critical damage velocity of the correspondent rice seed skin was much larger.