A R&D software platform for shape and topology optimization using body-fitted meshes
Résumé
Topology optimization is devoted to the optimal design of structures. It aims at finding the best material
distribution inside a working domain while fulfilling mechanical, geometrical and manufacturing specifications.
The need for lighter and efficient structural solutions has made topology optimization a vigorous
research field in both academic and industrial structural engineering communities. This contribution focuses
on PISCO, a Research and Development software platform for shape and topology optimization
where the computational process is carried out in a level set framework combined with a body-fitted approach. The level set method relies on the classical sensitivity analysis from the shape optimization
framework to compute a descent direction and advect the structural interface. In the present setting the
level set method is coupled with a remeshing routine which enables the reconstruction of a body-fitted
mesh at each step of the underlying optimization process. Since the structural interface
is known explicitely at each step of the iterative procedure, the body-fitted approach simplifies the
evaluation of the mechanical quantities of interest. PISCO is composed of several components including
an algorithmic toolbox specialized in the treatment of level sets, a generic interface to finite element
solvers, a toolbox handling mesh files in several classical formats, several algorithms for the resolution
of constrained optimization problems, physical and geometrical optimization criteria and an advanced
interface to the remeshing tool mmg3d. The components devoted to the physical analysis computations
and the constrained optimization algorithms are implemented in a generic fashion in dedicated modules.
The non-intrusiveness of the implementation is proved by the coupling with several external physical
solvers. We rely on a gradient-flow numerical optimization algorithm to handle the balancing between
the minimization of the objective and the non-violation of the constraints. Several industrial applications
are presented to highlight the capabilities of the platform.