Structural optimization considering flexibility (1st Report, Formulation of equation and application to compliant mechanisms)

Shinji Nishiwaki, Mary I. Frecker, Seungjae Min, Noboru Kikuchi

Research output: Contribution to journalArticle

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In structural design, the stiffest structure is considered optimal. However, a structure having flexible parts offers certain advantages over a rigid structure in terms of structural performance criteria. Moreover, flexible parts can offer mechanical function to the structure. A relatively new breed of mechanisms, compliant mechanisms, uses the design concept of structural flexibility to achieve a specified motion. In this paper, an optimization design procedure taking structural flexibility into consideration is proposed and applied to compliant mechanism design. First, structural flexibility is formulated using variational calculus, and a new multi-objective function is constructed. This objective function incorporates both maximum flexibility and minimum compliance using the homogenization method. Next, the optimization problem is solved using the Finite Element Method (FEM) and Sequential Linear Programming (SLP). Finally, some design examples of compliant mechanisms are presented, which confirm that the concept of flexible structure design can be used to design compliant mechanisms.

Original languageEnglish (US)
Pages (from-to)2657-2664
Number of pages8
JournalNippon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C
Issue number612
Publication statusPublished - Jan 1 1997


All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering

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