2019 Volume 60 Issue 697 Pages 33-38
In this study, a new peen-forming technique by means of vibration peening using a rectangular solid pin is developed. It is possible to produce a smaller x-direction (short side of the pin) curvature radius Rx than the z-direction (long side of the pin) curvature radius Rz . Vibration peening, which projects the pin into the specimen using the reciprocating motion of the electric hammer, is applied. In the experiment, Rz / Rx increases as the pin-tip radius r decreases. The motion of the pin is analyzed by the dynamic explicit finite-element method (FEM). The pin reciprocates between the hammer and the specimen and collides with the specimen 17 times in 0.2 s. The number of collisions agrees with the experimental result of 10 to 18 times in 0.2 s. The plastic strain distributions are determined using the maximum velocity of the pin. Peen forming is analyzed by the following method. In Step 1, the initial velocity is set for multiple pins, and plastic strain distributions generated by collisions are analyzed by the dynamic explicit FEM. In Step 2, plastic strain distributions analyzed in Step 1 are input to the specimen to analyze the deformation by the static implicit FEM. The analysis results indicating the increase in Rz / Rx with decrease in r agree with the experimental results.
