Third party funded individual grant
Start date : 01.01.2018
Compliant mechanisms are mechanical systems, which depict the function of a conventional mechanism, but without movable components (bearings, guide and joints). Instead, their function is based on the deformation of elastic areas. Design procedures for compliant mechanisms can be sharply divided into two categories: In the first (pseudo-static body approach), the procedure starts from a multi-body system, as with conventional mechanisms; in the other (continuum-based approach), a design space is defined in which a fixed or varying quantity of material is distributed in a defined manner.
A fundamental difference between the two approaches concerns the mechanism’s topology. In the first case the topology is to be assigned a-priori, while in the second case it is part of the result. This makes the design by multibody methods relatively easy, however at the price of a substantial reduction of the choice of possible layouts. Continuum-based approaches are normally based on formal optimization methods due to their inherent complexity.
A further important difference is related to the kind of deformation patterns which can be achieved: multibody methods tend to generate deformation patterns with elastic strain concentrated in particular areas, while continuum based methods allow arbitrary deformation patterns including smooth shape changes.
Known continuum based methods are mainly focused on the synthesis of mechanisms with a pseudo-mobility of one. The pseudo-mobility of a compliant mechanism corresponds to the number of independent kinematic quantities which are to be prescribed in order to control the static deformation of the mechanism with sufficient accuracy.
General-purpose procedures able to explicitly generate mechanisms with multiple pseudo-mobility are not available. The methodology to be developed in this project is intended to remove this deficiency. In addition, the new design approach shall be able to generate mechanisms with smooth deformation patterns.
The methodology to be developed in this project is of practical interest for any kinds of shape-adaptable structures, like morphing wings, adjustable seats and bed surfaces, as well as for classical transmission mechanisms for robotics and in general for automation tasks.