The development of additive technology has made it possible to produce metamaterials with a regularly recurring structure, the properties of which can be controlled, predicted, and purposefully implemented into the core of components used in various industries. Therefore, knowing the properties and behavior of these structures is a very important aspect in their application in real practice from the aspects of safety and operational reliability. This article deals with the effect of cell size and volume ratio of a body-centered cubic (BCC) lattice structure made from Acrylonitrile Butadiene Styrene (ABS) plastic on mechanical vibration damping and compression properties. The samples were produced in three sizes of a basic cell and three volume ratios by the fused deposition modeling (FDM) technique. Vibration damping properties of the tested 3D-printed ABS samples were investigated under harmonic excitation at three employed inertial masses. The metamaterial behavior and response under compressive loading were studied under a uniaxial full range (up to failure) quasi-static compression test. Based on the experimental data, a correlation between the investigated ABS samples’ stiffness evaluated through both compressive stress and mechanical vibration damping can be found.

Noise pollution is a negative factor that affects our environment. It is, therefore, necessary to take appropriate measures to minimize it. This article deals with the sound absorption properties of open-porous Acrylonitrile Butadiene Styrene (ABS) material structures that were produced using 3D printing technology. The material’s ability to damp sound was evaluated based on the normal incidence sound absorption coefficient and the noise reduction coefficient, which were experimentally measured by the transfer function method using an acoustic impedance tube. The different factors that affect the sound absorption behavior of the studied ABS specimens are presented in this work. In this study, it was discovered that the sound absorption properties of the tested ABS samples are significantly influenced by many factors, namely by the type of 3D-printed, open-porous material structure, the excitation frequency, the sample thickness, and the air gap size behind the sound-absorbing materials inside the acoustic impedance tube.

One of the phenomena that accompanies metal cutting is extensive plastic deformation and fracture. The excess material is plastically deformed, fractured, and removed from the workpiece in the form of chips, the formation of which depends on the type of crack and their propagation. Even in case of the so-called ‘continuous’ chip formation there still has to be a fracture, as the cutting process involves the separation of a chip from the workpiece. Controlling the chip separation and its patterning in a suitable form is the most important problem of the current industrial processes, which should be highly automated to achieve maximal production efficiency. The article deals with the chip root evaluation of two EN C45 and EN 16MnCr5 steels, focusing on the shear angle measuring and built-up edge observation as important factors influencing the machining process, because a repeated formation and dislodgement of built-up edge unfavorably affects changes in the rake angle, causing fluctuation in cutting forces, and thus inducing vibration, which is harmful to the cutting tool. Consequently, this leads to surface finish deterioration. The planing was selected as a slow-rate machining operation, within which orthogonal and oblique cutting has been used for the comparative chips’ root study. The planned experiment was implemented at three levels (lower, basic, and upper) for the test preparation and the statistical method, and regression function was used for the data evaluation. The mutual connections among the four considered factors (cutting speed, cutting depth, tool cutting edge inclination, and rake angle) and investigated by the shear angle were plotted in the form of graphical dependencies. Finally, chips obtained from both steels types and within both cutting methods were systematically processed from the microscopic (chip root) and macroscopic (chip pattern) points of view.

Truss structures are part not only technical practice but also our everyday life. It is very important to be designed safely. One of the tools that help a designer to avoid errors and to make the rightdecisions about a structure material, beam profile, shape of rod construction, etc. is virtual analysis. The article deals with the preliminary study of tower crane, which can be considered as the truss structure. Various types of structures are described in the introduction. The main part of the article is devoted to static analysis of the crane. The physical 3D model was prepared in reduced scale according to standards of European model trains NEM (Normen Europäischer Modellbahnen). Axial forces, stresses in beams, as well as the maximum possible load have been specified by analytical method. The strain analysis of crane has shown that the primary design of the structure was not acceptable and the construction would not be able to lift up required weight. Results were verified by virtual simulation insoftware Robot Structural Analysis. Therefore, the truss was reinforced by additional bars and newly remodelled tower crane has been tested to specify the maximum load of external weight.

This article explores the effect of carbon fiber content on the flexural strength of polymer concrete testing samples and compares the damping of polymer concrete and U-shaped steel profiles. The experiments involved and described herein consisted of flexural strength testing according to STN EN 12 390-5 Testing of Hardened Concrete, Part 5: Flexural Strength of Test Samples. The test results were evaluated graphically and by calculations and were further processed in various programs. The experimental results indicated that the highest flexural strength value was obtained by the test samples containing 12% of carbon fibers while culminating at 17.9 MPa. The results showed that the highest increase of flexural strength was caused by the addition of 3% of carbon fibers to the mixture, which increased the flexural strength by 4.2 MPa, or 26.75%. The results indicated that, based on the shape of the regression curve, flexural strength culminated at 13% carbon fiber content. The experimental results demonstrated that the tested polymer concrete test sample had a 6.87 times higher attenuation coefficient than the U-shaped steel profile. The results showed that the polymer concrete test sample No. 4 reduced vibration acceleration deviation by 93.5% in 0.005 sec and the U-shaped steel profile by 32.9%.

Lattice and gyroid structures are often subjected to additive technologies to produce various types of products, and the current market has a number of 3D printers that can be used for their production. The quality of the products produced in this way can be assessed on the basis of technical parameters and the filament used. Such an approach, however, is insufficient. In terms of quality, other product parameters need to be assessed, such as the surface texture and the internal structure’s porosity. For such an assessment, we can use the industrial tomography method and the method of roughness measurement via an optical microscope. The paper presents research on the assessment of the surface texture and porosity in lattice and gyroid structures. For the research, two types of test specimens—a specimen with a lattice structure and a specimen with a gyroid structure—were prepared. The obtained results proved that the 3D printing technology directly impacted the surface texture and porosity. For experimental specimens produced by SLS technology, we found that it was very important to carefully remove the excess powder, as unremoved powder can significantly affect the porosity results. For specimens produced by FDM technology, the research confirmed that some “gaps” between the layers were not pores but defects created during specimen production. When analyzing the surface using the Alicon Infinite G5 optical microscope, we found that the measured roughness results were directly impacted by the specimen’s surface color, the structure’s geometry, and the ambient light, which was confirmed by a red lattice experimental specimen, the surface of which could not be scanned. Based on the above, it can be stated that the selection of 3D technology for additive production needs must be given adequate attention regarding the quality of the created structures and textures.