Optimum design of porous structures for additive manufacturing with the Sequential Element Rejection and Admission (SERA) method

Abstract

Porous structures show important mechanical properties to weight ratio and great robustness regarding variations in the load direction, and because of that, they are considered interesting alternatives to their homogeneous counterparts. One clear example of such structures is found in the interior of bone structures that possess an intricate nucleus similar to a set of interconnected substructures. Their geometrical complexity made porous designs unattainable by conventional manufacturing techniques, so they would hardly be part of any practical application. Nevertheless, the relatively recent appearance of Additive Manufacturing considerably reduced this bump and opened a new era of investigations where optimum porous structures are sought through topology optimization techniques. This work introduces a topology optimization method based on the Sequential Element Rejection and Admission (SERA) method that generates optimized porous structures by forming optimal interconnected substructures within a fixed design domain. The method performs a subdivision of the original domain into a finite number of subdomains generating a series of reduced problems where an optimal material redistribution process is performed complying with local volume fractions. The results demonstrate the effectiveness of the presented procedure to generate detailed porous structures that mimic those that can be found in nature.