One of the current challenges of the aerospace industry is the exploration of new lightweighting structures to reduce fuel consumption and limit the environmental impact. The use of topology optimization techniques allows such weight reduction, minimizing design time and cost. However, complex designs are obtained, which are only possible to manufacture with additive manufacturing. Consequently, the numerical optimization must be combined with 3D printing constraints to ensure manufacturability (minimal length scale and overhang constraints) and avoid the apparition of complex shapes and volumes with unintuitive holes. Thus, the aim of this paper is to study the feasibility of optimal design when considering overhang constraints in the addittive manufacturign process. We introduced the concept of anisotropic perimeter to penalize the overhang constraint in the 3D printing direction. Different case studies are defined in order to assess their feasibility. Results obtained show that local bars with small length scales are removed and vertical tendency orientation of bars are generally obtained.