Shape Design of Compliant Mechanisms Using Bezier Curves

• Main Authors: Youg-Jen Cheng, 鄭詠仁
• Other Authors: Chao-Chieh Lan
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/87323341506500807384

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 97 === A method using Bezier curves to design the shape of compliant mechanisms is presented in this thesis. Compared to continuum-element or frame-element based topology design methods, the use of curved beam elements can improve the shape smoothness of compliant mechanisms. Furthermore, the stress concentration can also be reduced. We apply Bezier curves to construct the shape of compliant mechanisms due to their simple expression and ease of manipulating shapes. The analyses of compliant mechanisms are based on an incremental linearization approach. This approach provides stable, rapid, yet accurate numerical computation since the deformation problem is linearized. The presented design method applies two steps to design the topology and shape of compliant mechanisms, respectively. The first step uses a few straight beams to construct the topology of a compliant mechanism and the second step accomplishes the object by determining the optimal shapes of beams. Key to the success of this method is that it improves the optimal results by finding better beam shapes rather than using more beam elements. Thus the design process can be simply constructed and optimal results rapidly obtained. Three numerical examples are illustrated and compared for validation. Finally, we design and manufacture a bi-stable compliant mechanism to show that the design method can be applied to real design problems. We expect the two-step design method based on Bezier curves can efficiently assist the design of practical compliant mechanisms.