In order to improve the steel structures protection against fire, the intumescent paint method can be applied along with other methods. The intumescent paints layers numbers have to be optimized though. An uniform layer of intumescent paint, foreseen to protect the whole structure, represents both a higher cost and an uneconomical solution. The authors started examination on this problem, by analyzing one of the most recommended steel joints from the earthquake-proof criteria. The conceived and realized original electric furnace allows both a high-accuracy tuning/adjustment of the temperature and a good-stability of its, by means of the original electronic command. In order to perform high-accuracy and full-field monitoring of the displacements, the authors used a modern optical non-contact system, the Video Image Correlation one. The obtained preliminary results are very promising and will be continued in the next period by this international team.

Nowadays, the real structures (considered as prototypes) subjected to fire are analysed by means of the behaviours of some reduced scale structures (defined as models). These prototype–model correlations are governed by the so-called dimensional analysis (DA) methods. These methods, starting from the Buckingham theorem, offer several dimensionless variables and based on them is the so-called Model Law (ML), which is able to foresee the predictable prototype’s answer based on the results of the experimental investigations performed exclusively on the model (usually manufactured at a reduced scale). Based on the MDA principles, in a previous paper the authors elaborated the complete ML for the heat transfer in beams with rectangular-hole cross-sections, considering unprotected as well as thermally protected structural elements. The authors, based on meticulous experimental investigations, obtained the validation of this ML for the unprotected steel members. In this contribution, the authors offer in a similar manner the ML validation for intumescent paint-protected steel members and thus the complete validation of their original ML. In their theoretical and experimental investigations, the authors involved both a real column’s element combined with its models manufactured at 1:2 and 1:4, as well as 1:10 scales too. Consequently, the obtained ML can be considered as generally valid, involving a real structural element and its model manufactured at the desired scale.

In this contribution, the authors continued their initial study on the efficiency of the analysis of experimentally obtained temperature curves, in order to determine some basic parameters that are as simple and reliable as possible, such as “m”, the heat transfer coefficient. After the brief review of the previous results, on which the present article is based, the authors offered a brief argumentation of the importance of dimensional methods, especially the one called modern dimensional analysis, in these theoretical-experimental investigations regarding the propagation of the thermal field of structural elements with solid sections, and especially with tubular-rectangular sections. It could be concluded that modern experimental investigations mostly follow the behavior of models attached to the initial structures, i.e., prototypes, because there are clear advantages in this process of forecasting the behavior of the prototype based on the measurement results obtained on the attached model.

By means of its facilities, AM brings several advantages in comparison with the classical manufacturing technologies. Nowadays, there are a huge number of unexplored directions, which assure AM will become a very powerful manufacturing process in the next period, with an undoubted low cost and reduced material consumption, as well as optimal stiffness and competitiveness technology. Between the unexplored (or less-explored) directions, one has to mention the dimensional methods’ involvement in gaining an optimal, highly competitive final product. This means that instead of the real structural element, named the prototype, the engineers will perform high-accuracy tests on the attached reduced-scale models, whose experimental results are extended to the prototype by means of the deduced model law (ML). The authors, based on their previous theoretical research as well as experimental investigations, offer a new approach, which is less implemented in AM technologies. Based on the obtained results, these dimensional methods are very promising, especially the last one, the so-called Modern Dimensional Analysis (MDA), conceived by Thomas Szirtes and described in the following paper. Starting with the nowadays-applied dimensional methods’ critical analysis, the authors will present evidence for the advantages of MDA, especially on the polymer-based AM technology. They will prove that MDA represents a very promising, as well as easy approach, which through its implementation can offer a higher competitiveness for AM technologies. As an illustration of the advantages of MDA, the authors conceived several MDA approaches for a given structural element’s case (a cantilever beam, with an internal-ribbed structure loaded at its free end by means of a vertical concentrated load), which, through their high accuracy in experimental-validated MLs, offer very good accuracy in model–prototype correlation. The deviations between the effective measured values of the displacements on the prototypes and those predicted, based on the values of the measurements on the models assigned to the prototypes by the validated MLs, were 1.06, 1.60, and 2.35%, respectively. In the authors’ opinion, MDA can represent a starting point for conceiving a highly competitive product with an optimal filling, as well as the deposition of layers using AM technologies. Based on the authors’ best knowledge, up to this moment, it seems that this engineering area does not fully apply the advantages of MDA, only in few limited cases, analyzed in the following.