Preface on mechanics of additive manufacturing—Part II

In the first part of this two-part special issue, the focus is on the modeling and simulation of elementary processes within various materials that can be used for additive manufacturing. It comprises selective laser sintering of polymers, topology optimization in the context of additively manufactured structures, a general overview on the challenges related to the modeling and simulation of powder bed fusion additive manufacturing as well as the modeling of phase changes during Selective Laser Melting and the related analysis of process-induced inherent strains. As sophisticated as these models may be, they also require experimental data for verification and validation. The more complex the modeled and simulated processes, as well as the material models themselves, become the more important becomes the sound and comprehensive experimental characterization and experimental investigation of the effective material behavior. Even with accurate and experimentally verified material and process models successfully developed and established the general challenge of their algorithmic implementation remains. In this context, it is essential to establish efficient and robust numerical methods, some of which have to be newly developed due to the high numerical complexity. The contributions of this Part II of the Special Issue of the Surveys for Applied Mathematics and Mechanics (GAMM-Mitteilungen) mainly focus on these above-mentioned aspects: The paper referenced by Kollmannsberger and Kopp [1] elaborates advanced modeling and simulation approaches with emphasis on different time scales. This includes, among other topics, the investigation and comparison of different time-stepping schemes with special focus on robustness, prevention of oscillating solutions and general applicability. In Zhou et al. [2], a multilayer phase-field simulation of selective sintering process and the calculation of effective mechanical properties and residual stresses is proposed. In this regard, quantitative relations between the process parameters and the microstructure and its properties are established. The contribution of Schirmer et al. [3] addresses the additive manufacturing of a novel class of bio-based materials via binder-jetting. The highly customizable printed structures are recyclable and use renewable raw materials that are often industrial by-products. The article presents a proof-of-concept study, in which digital image correlation, finite element analysis and optimization techniques are combined to characterize the heterogeneous structural behavior of such 3D-printed biodegradable materials. The work presented in Raßloff et al. [4] aims at the prediction of structure–property linkages for additively manufactured materials with a particular focus on process-induced imperfections like pores. It uses light microscopy and X-ray computed tomography to determine microstructure characteristics of Ti–6Al–4V in combination with microscale simulations to assess the influence of imperfections and microstructural variations on the materials’ fatigue performance.