Improving mechanical ice protection systems with substrate shape optimization

Mechanical and electro-mechanical de-icing systems are low-energy ice protection solutions based on fracture mechanisms. It can, however, be difficult to obtain the protection of an entire surface due to the limited propagation of fractures for some mechanisms. This article shows how it is possible to reshape the substrate in order to favor the propagation of adhesive fracture at the ice/substrate interface. The first part of the paper introduces an analytical beam theory approach for running computations quickly, making it possible to achieve parametric optimization of the substrate thickness and maximize the propagation length. The optimization results were validated using FEM software and tests on an aluminum prototype. A second method is also studied in this paper, topology optimization is used on a 2D finite element model to minimize the substrate mass of the proposed solution and adhesive crack propagation is assessed in comparison with the mass impact. For different boundary conditions, propagation ranges can be increased by up to 150% with a mass increase limited to 50%. Using topology optimization, the additional mass could be reduced by >60% while maintaining the same performances.