This paper discusses excessive vibration of propulsion plants and analyses global experience in practical application of the propellers made of composite materials with improved acoustic performance. ...The author points out that composite materials and additive technologies could be a viable path towards marine propellers with improved acoustic and vibration properties.
World trends and prospects of development of technological equipment complexes are considered. The applied stages and phases of machining equipment design are analyzed by means of constructing design ...schemes traditional for machine mechanics. It is proposed to create technological machine tool complexes by layout synthesis with the help of element base, which should contain functional technological and service modules, and the service purpose of the machine tool should include the nomenclature of manufactured surface modules. It is shown that the prospects of application of energy flows for intensification of machining processes should be analyzed at the early stages of design, using thermal and electrophysical criteria to study the emerging relations in the system. It is suggested to start designing mechatronic systems of machine tool complexes from the analysis of structural relations of information technologies in hybrid production including traditional and additive technologies.
An approach to the experimental and computational study of the shear properties of honeycomb cores (HC) produced using Fused Deposition Modeling (FDM) technology is proposed. The experimental ...approach is based on a new sample type for testing HCs for shear. This sample contains two HCs and three steel plates. Shear tests are carried out in the TiraTest 2300 universal tensile testing machine. The HCs are made of ULTEM 9085 and PLA with FDM technology, which is implemented in the 3D Fortus 900 system. The tests resulted in obtaining the shear properties of the HCs by averaging the stress-strain curves of five samples. As follows from the analysis of the experimental results, brittle destruction of an HC is observed. Before its destruction, the value of shear deformation for samples made of PLA was 0.0134, and for samples made of ULTEM, 0.0257. The experimental analysis was accompanied by numerical finite element (FE) modeling of shear experiments, taking into account the deformation of the equipment. With the FE modeling of the experiments, to describe the behavior of the samples, it is necessary to take into account the influence, on the measurements of the shear properties, of the equipment and the deformation of each honeycomb cell. The deformation of three plates was taken into account; the elastic properties of the adhesive joint were not taken into account. A computer model of the deformation of the HCs with equipment was built using ANSYS Design Modeler. With FE modeling, only the elastic behavior of the HCs was considered.
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