We show how composites with extremal or unusual thermal expansion coefficients can be designed using a numerical topology optimization method. The composites are composed of two different material phases and void. The optimization method is illustrated by designing materials having maximum thermal expansion, zero thermal expansion, and negative thermal expansion. Assuming linear elasticity, it is shown that materials with effective negative thermal expansion coefficients can be obtained by mixing two phases with positive thermal expansion coefficients and void. We also show that there is no mechanistic relationship between negative thermal expansion and negative Poisson's ratio.

Date Published: 14 February 1997
PDF: 9 pages
Proc. SPIE 3040, Smart Structures and Materials 1997: Smart Materials Technologies, (14 February 1997); doi: 10.1117/12.267131

Published in SPIE Proceedings Vol. 3040:
Smart Structures and Materials 1997: Smart Materials Technologies
Wilbur C. Simmons; Ilhan A. Aksay; Dryver R. Huston, Editor(s)