Maximization of the fundamental eigenfrequency of micropolar solids through topology optimization

Aim of this work is the maximization of the fundamental eigenfrequency of 2D bodies made of micropolar (or Cosserat) materials using a topology optimization approach. A classical SIMP–like model is used to approximate the constitutive parameters of the micropolar medium. A suitable penalization is introduced for both the linear and the spin inertia of the material, to avoid the occurrence of undesired local modes. The robustness of the proposed procedure is investigated through numerical examples; the influence of the material parameters on the optimal material layouts is also discussed. The optimal layouts for Cosserat solids may differ significantly from the truss–like solutions typical of Cauchy solids, as the intrinsic flexural stiffness of the material can lead to curved beam-like material distributions. The numerical simulations show that the results are quite sensitive to the material characteristic length and the spin inertia.

[1]  A. Eringen,et al.  LINEAR THEORY OF MICROPOLAR ELASTICITY , 1965 .

[2]  W. E. Jahsman,et al.  A Quest for Micropolar Elastic Constants , 1975 .

[3]  A. Seiranyan Multiple eigenvalues in optimization problems , 1987 .

[4]  K. Svanberg The method of moving asymptotes—a new method for structural optimization , 1987 .

[5]  M. Bendsøe,et al.  Generating optimal topologies in structural design using a homogenization method , 1988 .

[6]  M. Bendsøe Optimal shape design as a material distribution problem , 1989 .

[7]  M. Zhou,et al.  The COC algorithm, Part II: Topological, geometrical and generalized shape optimization , 1991 .

[8]  R. Borst,et al.  Localisation in a Cosserat continuum under static and dynamic loading conditions , 1991 .

[9]  N. Kikuchi,et al.  Solutions to shape and topology eigenvalue optimization problems using a homogenization method , 1992 .

[10]  R. Lakes Strongly Cosserat Elastic Lattice and Foam Materials for Enhanced Toughness , 1993, Cellular Polymers.

[11]  H. Mlejnek,et al.  An engineer's approach to optimal material distribution and shape finding , 1993 .

[12]  R. Lakes,et al.  Size effects due to Cosserat elasticity and surface damage in closed-cell polymethacrylimide foam , 1994, Journal of Materials Science.

[13]  George I. N. Rozvany,et al.  On singular topologies in exact layout optimization , 1994 .

[14]  Ichiro Hagiwara,et al.  Eigenfrequency Maximization of Plates by Optimization of Topology Using Homogenization and Mathematical Programming , 1994 .

[15]  N. Olhoff,et al.  Multiple eigenvalues in structural optimization problems , 1994 .

[16]  N. Kikuchi,et al.  Topological design for vibrating structures , 1995 .

[17]  Niels Olhoff,et al.  Topology Optimization of Plate and Shell Structures with Multiple Eigenfrequencies , 1995 .

[18]  Roderic S. Lakes,et al.  EXPERIMENTAL METHODS FOR STUDY OF COSSERAT ELASTIC SOLIDS AND OTHER GENERALIZED ELASTIC CONTINUA , 1995 .

[19]  S. Forest,et al.  Cosserat overall modeling of heterogeneous materials , 1998 .

[20]  M. Bendsøe,et al.  Material interpolation schemes in topology optimization , 1999 .

[21]  C. Swan,et al.  A SYMMETRY REDUCTION METHOD FOR CONTINUUM STRUCTURAL TOPOLOGY OPTIMIZATION , 1999 .

[22]  Georges Cailletaud,et al.  Cosserat modelling of size effects in the mechanical behaviour of polycrystals and multi-phase materials , 2000 .

[23]  N. L. Pedersen Maximization of eigenvalues using topology optimization , 2000 .

[24]  Effective properties of cosserat composites with periodic microstructure , 2001 .

[25]  B. Bourdin Filters in topology optimization , 2001 .

[26]  T. E. Bruns,et al.  Topology optimization of non-linear elastic structures and compliant mechanisms , 2001 .

[27]  M. A. Kattis,et al.  Finite element method in plane Cosserat elasticity , 2002 .

[28]  F. Keulen,et al.  Cosserat moduli of anisotropic cancellous bone: A micromechanical analysis , 2003 .

[29]  D. Veber,et al.  Optimal topologies for micropolar solids , 2006 .

[30]  M. Gei,et al.  Effect of internal length scale on optimal topologies for cosserat continua , 2006 .

[31]  Jakob S. Jensen,et al.  On maximal eigenfrequency separation in two-material structures: the 1D and 2D scalar cases , 2006 .

[32]  R. Naghdabadi,et al.  Computational aspects of the Cosserat finite element analysis of localization phenomena , 2006 .

[33]  O. Sigmund Morphology-based black and white filters for topology optimization , 2007 .

[34]  N. Olhoff,et al.  Topological design of freely vibrating continuum structures for maximum values of simple and multiple eigenfrequencies and frequency gaps , 2007 .

[35]  Matteo Bruggi,et al.  Eigenvalue-based optimization of incompressible media using mixed finite elements with application to isolation devices , 2008 .

[36]  George I. N. Rozvany,et al.  A critical review of established methods of structural topology optimization , 2009 .

[37]  G. Felice,et al.  Continuum modeling of periodic brickwork , 2009 .

[38]  Xikui Li,et al.  A micro–macro homogenization approach for discrete particle assembly – Cosserat continuum modeling of granular materials , 2010 .

[39]  Anders Clausen,et al.  Efficient topology optimization in MATLAB using 88 lines of code , 2011 .

[40]  M. Bendsøe,et al.  Topology Optimization: "Theory, Methods, And Applications" , 2011 .

[41]  A. Taliercio,et al.  Topology optimization of three-dimensional non-centrosymmetric micropolar bodies , 2011, Structural and Multidisciplinary Optimization.