  Selecting the optimal material for a part designed through topology
optimization is a complex problem. The shape and properties of the Pareto front
plays an important role in this selection. In this paper we show that the
compliance-volume fraction Pareto fronts of some topology optimization problems
in linear elasticity share some useful properties. These properties provide an
interesting point of view on the efficiency of topology optimization compared
to other design approaches such as parametric structural optimization. We
construct a simple meta-model which requires only one full topology
optimization to fit the whole Pareto fronts. Precise Pareto fronts are obtained
independently. The fast meta-model constructed has a maximum error of 6.4% with
respect to these precise Pareto fronts, on the different problems tested. The
selection of the optimal material is then successfully tested on the mass
minimization of an MBB beam with an illustrative choice of 4 materials.
