Scientific paper ID 2304 : 2022/3
VIBRO-ACOUSTIC ASSESSMENT OF TECHNICAL CONDITION OF 3D PRINTED SAMPLES
The task of the present work is to control the structure of 3D printed machine elements of PET-G material in order to achieve pre-justified mechanical properties. On the one hand, the setting of the technological mode of the printer by means of specialized software provides setting of detailed information and allows toachieve the desired by the user characteristics of the finished product. On the other hand, the performance of the finished product may change due to unreported deviations of the material, the printer, etc.
In order to achieve the set task, the mass and the natural frequencies of the elements are studied simultaneously. Data from vibro-acoustic analysis of tubes produced under different technological regimes, for which a change in the density of the material from 1132 to 1428 kg / m3 and the modulus of linear deformation - from 800 to 1965 MPa are used. They are introduced as input characteristics in a specialized engineering product for determining the resonant frequencies of printed machine elements. Resonant frequencies of the produced machine elements are determined theoretically. They are compared with the actual values of the machine elements and the results give a basis for assessing the technical condition.
The methodology was tested by examining a printed gear and rack. They are manufactured with large cavities on the inside of the parts and with relatively good surface quality on one side, leaving unclosed on the other side. The sound spectrum in the range up to 20 kHz was recorded and the resonant frequencies of the samples were determined. The masses were measured and the density of the material was calculated using the volume of the model. Based on the created empirical dependences, data on the modulus of linear deformation for each sample were obtained.
Research indicates that the methodology used is also applicable to the control of machine elements produced by energy-saving technologies. It would find application for non-destructive quality control of small series of responsible machine elements in order to reduce the time and resource for evaluation of mechanical properties.
безразрушителна вибро-акустична оценка на 3D принтирани машинни елементи.Non-destructive vibro-acoustic evaluation of 3D printed machine elements.Ivan Kolarov
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