Topology optimization of elastic continua using restriction

This is a study of restriction methods in topology optimization of linear elastic continua. An ill-posed optimization problem is transformed into a well-posed one by restricting the feasible set, hence the term restriction. A number of restriction methods are presented and compared, of which some have been treated previously in the literature and some are new. Advantages and drawbacks of the methods are discussed from a theoretical as well as a numerical point of view. The problems of minimizing compliance and designing compliant mechanisms constitute the base for these discussions and several numerical examples are presented that illustrate features of the various restriction methods.