In this article, the possibility and the pertinence of using 3D printed polymeric materials for models in modal tests on shaking tables were recognized. Four stages of the research have been linked: The material properties investigation, the field experiment on the modal properties of the reinforced concrete chimney (a prototype), the shaking table tests on the modal properties of the 3D printed polymer model of the chimney, scaled according to the similarity criteria, and the numerical calculations of the FE model of the 3D printed mockup. First, the investigation of the properties of 3D printed polymer materials revealed that the direction of lamination had no significant effect on the modulus of elasticity of the material. This is a great benefit, especially when printing models of tall structures, such as chimneys, which for technical reasons could only be printed in a spiral manner with the horizontal direction of lamination. The investigation also proved that the yield strength depended on the direction of the lamination of the specimens. Next, the natural frequencies of the chimney, assessed through the field experiment and the shaking table tests were compared and showed good compatibility. This is a substantial argument demonstrating the pertinence of using 3D printed polymer materials to create models for shaking table tests. Finally, the finite element model of the 3D printed polymer mockup was completed. Modal properties obtained numerically and obtained from the shaking table test also indicated good agreement. The presented study may be supportive in answering the question of whether traditional models (made of the same material as prototypes) used in shaking table tests are still the best solution, or whether innovative 3D printed polymer models can be a better choice, in regard to the assessment of the modal properties and the dynamic performance of structures.

In this study, we investigated the vibration of adhesively bonded composite cantilevers consisting of two beech wood lamella and a bondline of flexible polyurethane. The beams had a constant total height, while the thickness of the adhesive layer varied. We analyzed both the driven and free vibration of a single cantilever beam and a cantilever with an additional mass attached to its end. The eigenfrequencies were determined using Fourier analysis of a sweep load response, the response to an impact load excited using an impact hammer, and the response observed via the manual displacement of the beam’s tip. The system’s damping was estimated according to the recorded logarithmic decrement. Theoretical estimates of the fundamental natural frequency were obtained using the γ-method and employing a linear elastic theory of composite beams. A numerical modal analysis was carried out using the finite element method. Upon comparing the results of our experiments with the numerical estimates and theoretical predictions, a fair agreement was found.

Bus and tram traffic in urban environments generates mechanical vibrations that can threaten both the structural integrity of buildings and the well-being of residents. The intensity of these effects is determined by many factors, including the quality of roads or tracks, the type of vehicles used, the distance of buildings to vibration sources, and the speed of their travel. The question is, can speed have a decisive influence on the generation of ceiling vibrations and the comfort of its residents? The operation of buses and trams can cause significant discomfort, especially in residential areas located in the immediate vicinity of roads and tram tracks. Such disturbances can negatively affect the quality of life, causing sleep disorders, increasing stress levels, and reducing concentration or productivity. The presented work shows the results of experimental studies on vibration comfort in buildings, specifically regarding the speed of passing trams and buses.