An Analysis of Ultrasonic Vibration on Micro Drawing Processes

• Main Authors: Wang, Li-Wei, 王笠惟
• Other Authors: Huang, Yuung-Ming
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/34360691662933497864

碩士 === 聖約翰科技大學 === 自動化及機電整合研究所 === 102 === This research employs I-DEAS software to build up the model, DYNAFORM finite element analysis software to simulate the micro deep drawing process assisted with ultrasonic vibration with stainless steel plate. The experimental materials adopt SUS304 stainless steel thin plates which the mechanical properties were attained through standard tension testing. To confirm the suitability and feasibility, we apply ultrasonic vibration to micro deep drawing die and then discuss the relation between punch load and stroke, the distribution of main stress, deforming process and forming limit. In terms of round cups forming process, the punch load increases with increasing stroke. This increase continues up until the specimen apart from the punch then the forming load trends to decrease gently. The local region at the place formed specimen contact with punch corner where the minimum thicknesses have. Through limit drawing ratio which defined by round punch diameter and initial specimen diameter the limit drawing ration of round cup is 1.833. While applied ultrasonic vibration may efficiency lower punch load and improve the limit drawing ratio to 1.913. The drop in maximum load from 1707.44 N decreases to 1246.72 N in effect to a specimen diameter 10.5 mm, lower the maximum load 26.98%. On the condition forming force 1200 N, the stroke was 18.771% higher than the experiment result without ultrasonic vibration. On the elliptic cups forming process, the local region at the place specimen contact with the major axis of punch where the minimum thickness has, while the large radius of curvature of minor axis the specimen have smaller axial tension stress, the thickness variation is unobvious. Through limit drawing ratio which defined by elliptic punch circumference and initial specimen circumference the limit drawing ratio of elliptic cup is 2.015. While applied ultrasonic vibration may efficiency lower punch load and improve the limit drawing ratio to 2.116. The drop in maximum load from 1472.23 N decreases to 1266.17 N in effect to a specimen diameter 10 mm, lower the maximum load 14%. On the condition forming force 1000 N, the stroke was 8.917% higher than the experiment result without ultrasonic vibration. The micro deep drawing assisted with ultrasonic vibration has been proved to lower punch load and increase stroke at the same time through the forming process, eventually attained better formed products. To avoid failure in forming, the gate between punch and die has to be precious controlled, or the specimen could be draw unequally.