Tailorable thermal expansion hybrid structures

A design concept is presented for a macro or microstructure that combines materials with differing thermal expansion to achieve an overall effective expansion that differs substantially from either of the constituents. Near-zero-CTE and isotropic negative expansion designs are achieved by creating compliant structures where overall expansion is compensated by internal bending deformation. Such structures have application where dimensional stability is required when subject to large thermal gradients, e.g. space mirrors. In this paper, we present closed form analytic expressions for prediction of the effective expansion, and consequent internal stressing, of the structure, as well as several finite element simulations that demonstrate the design performance under non-uniform thermal load.

[1]  S. Timoshenko,et al.  Analysis of Bi-Metal Thermostats , 1925 .

[2]  Anthony G. Evans,et al.  Concepts for structurally robust materials that combine low thermal expansion with high stiffness , 2007 .

[3]  N. Allan,et al.  Negative thermal expansion , 2005 .

[4]  Roderic S. Lakes,et al.  Cellular solid structures with unbounded thermal expansion , 1996 .

[5]  S. Shtrikman,et al.  A variational approach to the theory of the elastic behaviour of multiphase materials , 1963 .

[6]  C. D. Meyer,et al.  Synthesis and thermal expansion of ZrO2/ZrW2O8 composites , 2005 .

[7]  Xavier Colonna de Lega,et al.  Deformation analysis of a communication telescope structure under nonuniform heating using holographic interferometry , 1998, Electronic Imaging.

[8]  Zvi Hashin,et al.  Effective thermal expansion coefficients and specific heats of composite materials , 1970 .

[9]  Salvatore Torquato,et al.  Thermal expansion of isotropic multiphase composites and polycrystals , 1997 .

[10]  John S. O. Evans,et al.  Negative Thermal Expansion from 0.3 to 1050 Kelvin in ZrW2O8 , 1996, Science.

[11]  John W. Halloran,et al.  Negative thermal expansion artificial material from iron-nickel alloys by oxide co-extrusion with reductive sintering , 2004 .

[12]  S. Torquato,et al.  Design of materials with extreme thermal expansion using a three-phase topology optimization method , 1997 .

[13]  D. H. Young,et al.  Theory of Structures , 1965 .

[14]  Richard Schapery.  Thermal Expansion Coefficients of Composite Materials Based on Energy Principles , 1968 .

[15]  A. Sleight.  Negative thermal expansion materials , 1997 .

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

[17]  Noboru Kikuchi,et al.  Advances in computational design and optimization with application to MEMS , 2001 .

[18]  T. R. Tauchert,et al.  Energy Principles in Structural Mechanics , 1974 .

[19]  A. Sleight,et al.  Negative Thermal Expansion and Phase Transitions in the ZrV2-xPxO7 Series , 1995 .

[20]  R. Lakes.  Cellular solids with tunable positive or negative thermal expansion of unbounded magnitude , 2007 .