The industrial interest in additive manufacturing (AM) techniques is currently increasing for the realization of functional mechanical components. For this reason, the structural simulation of parts or complete structures made using this new manufacturing technique is gaining considerable importance. To realise accurate finite element models for the purpose of predicting the dynamic or static behaviour of the component printed and avoid unexpected failures, it is necessary to be aware of some mechanical and physical properties of the print material. Unfortunately, in the literature, it is very difficult to find all the data necessary to perform static or dynamic simulations of 3D printed parts. In this context, this activity aims to determine all these mechanical and physical properties for parts made in White-Pearl Polylactic-acid (PLA) Ultimaker filament using the Fused Filament Fabrication (FFF) technique. A set of printing parameters was chosen and kept constant in all tests which, based on literature data, maximizes the static strength and the fatigue limit of the component. Only the building direction was varied to increase the applicability of the obtained results to any geometry. The main results found for the horizontally moulded specimens (representing the best constructive solution) are the Ultimate Tensile Strength equal to 57.15 MPa, the elastic modulus 2606 MPa, the fatigue limit evaluated at $$2 \times 10^{6}$$2 × 10 6 cycles equal to 13.5 MPa, the damping and density of the material of 0.008 dimensionless value and 1.1246 g/cm³, respectively. Only thanks to the obtained results, finite element models can be developed for reliable static and dynamic analysis.

Additive manufactured structures are replacing the corresponding ones realized with classical manufacturing technique. As for metallic structures, 3D printed components are generally subjected to dynamic loading conditions which can lead to fatigue failure. In this context, it is useful, and sometimes mandatory, to determine the fatigue life of such components through numerical simulation. The methods currently available in literature for the estimation of fatigue life were originally developed for metallic structures and, therefore, it is now necessary to verify their applicability also for components fabricated with different materials. To this end, in the current activity three of the most used spectral methods for the estimation of fatigue life were used to determine the fatigue life of a 3D printed Y-shaped specimen realized in polylactic acid subjected to random loads with the aim of determining their adaptability also for this kind of materials. To certify the accuracy of the numerical prediction, a set of experimental tests were conducted in order to obtain the real fatigue life of the component and to compare the experimental results with those numerically obtained. The obtained outcomes showed there is an excellent match between the numerical and the experimental data, thus certifying the possibility of using the investigated spectral methods to predict the fatigue life of additive manufactured components.

In this paper, the mechanical behavior of concrete twin-shaft mixers is analyzed in terms of power consumption and exchanged forces between the mixture and the mixing organs during the mixing cycle. The mixing cycle is divided into two macro phases, named transient and regime phase, where the behavior of the mixture is modeled in two different ways. A force estimation and power consumption prediction model are presented for both the studied phases and they are validated by experimental campaigns. From the application of this model to different machines and by varying different design parameters, the optimization of the power consumption of the concrete twin-shaft mixers is analyzed. Results of this work can be used to increase productivity and profitability of concrete mixers and reduce energy waste in the industries which involve mixing processes.

This paper focuses on the effect of rapid annealing on Non-Grain Oriented Electrical Steel (NGO) in terms of microstructure, mechanical properties, and magnetic properties. The Ultra-Fast Heating (UFH) tests were performed by a transversal induction heater on NGO electrical steel samples (cold rolled down to 0.5 mm), varying the heating power (80 kW and 90 kW) and the speed of the strip through the induction heater. This allowed us to exploit heating rates (HR) in the range of 200–300 °C/s and targeting peak temperature (T_peak) up to a maximum of 1250 °C. The comparison between the microstructure as obtained by conventional annealing and the ultra-fast heating process highlights a clear effect in terms of grain size refinement provided by the UFH. In particular, the average grain size as obtained by UFH ranges two/three times lower than by a conventional process. The results show the possibility of applying UFH to NGO steels, targeting mechanical properties such as those obtained by the standard process, combined with the benefits from this innovative heat treatment in terms of green energy and the minimization of CO₂ emissions. Magnetic characterization performed by a single sheet tester (30 × 90 mm) showed that the values of core losses are comparable with conventional NGO grades.