Citation: Irska, I.; Kramek, G.; Mi ˛ adlicki, K.; Dunaj, P.; Berczy´ nski, S.; Piesowicz, E. Towards Highly Efficient, Additively Manufactured Passive Vibration Eliminators for Mechanical Systems. Materials 2023, 16, 1250. https://doi.org/10.3390/ ma16031250 Academic Editor: Justyna Kucinska-Lipka Received: 21 December 2022 Revised: 21 January 2023 Accepted: 29 January 2023 Published: 1 February 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Article Towards Highly Efficient, Additively Manufactured Passive Vibration Eliminators for Mechanical Systems Izabela Irska * , Grzegorz Kramek, Karol Mi ˛ adlicki , Pawel Dunaj , Stefan Berczy ´ nski and El ˙ zbieta Piesowicz Department of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, Szczecin, al. Piastów 19, 70-310 Szczecin, Poland * Correspondence: izabela.irska@zut.edu.pl Abstract: Structural damping largely determines the dynamic properties of mechanical structures, especially those whose functioning is accompanied by time-varying loads. These loads may cause vibrations of a different nature, which adversely affects the functionality of the structure. Therefore, many studies have been carried out on vibration reduction methods over the last few years. Among them, the passive vibration damping method, wherein a suitable polymer system with appropriate viscoelastic properties is used, emerges as one of the simplest and most effective methods. In this view, a novel approach to conduct passive elimination of vibrations, consisting of covering elements of structures with low dynamic stiffness with polymeric pads, was developed. Herein, polymer covers were manufactured via fused filament fabrication technology (3D printing) and were joined to the structure by means of a press connection. Current work was focused on determining the damping properties of chosen polymeric materials, including thermoplastic elastomers (TPE). All investigated materials were characterized by means of differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and mechanical properties (tensile test and Shore hardness). Lastly, the damping ability of pads made from different types of polymers were evaluated by means of dynamic tests. Keywords: additive manufacturing; vibration eliminators; passive vibration damping 1. Introduction Vibrations are a common problem in machinery and mechanical structures, especially those with time-varying loads. This problem affects a wide range of industries, including the mechanical, civil, aerospace, automotive, and marine industries. Variable loads can cause vibrations with different characteristics which adversely affect the structure and operation of the machine [1–4]. Therefore, a key parameter to consider when designing a machine and its dynamic properties is structural damping. However, it is not always possible to design a machine from scratch or significantly modify an already existing one. For this reason, methods to eliminate vibrations are being studied, not only for new structures, such as a frame for a delta robot [2], but also for existing ones [5,6]. Methods to suppress vibrations, as well as the negative effects caused by them, can be divided into three main groups: (i) active, (ii) passive, and (iii) semi-active, which is the combination of both active and passive methods [7–9]. Active methods of vibration elimination require supplying additional external en- ergy to the mechanical system. Most often, an additional eclectic [10], pneumatic [11], hydraulic [12], or hybrid [13] device is used for this purpose. These methods are often very complicated and expensive because they require additional control, measurement, and actuation systems. Active methods are used most widely in the aerospace engineering [13] or automotive industries [14]. Passive methods of eliminating vibrations involve modifying the structure or parame- ters of the mechanical system [15]. The parameters are changed to increase the ability of Materials 2023, 16, 1250. https://doi.org/10.3390/ma16031250 https://www.mdpi.com/journal/materials