This page has only limited features, please log in for full access.
In this work, the fracture mechanics properties of polyamide (PA) specimens manufactured by the selective laser sintering (SLS) technology are investigated, in which an embedded crack-like notch was inserted in the design and produced during the additive manufacturing (AM) phase. To cover a wide variety of mode I/II mixity levels, the inclined asymmetrical semicircular specimen subjected to three points loading (IASCB) was employed. The investigation was carried out by analyzing the full displacement field in the proximity of the crack tip by means of the digital image correlation (DIC) technique. To characterize the material, which exhibits a marked elastic-plastic behavior, the quantity J-integral was evaluated by two different methods: the first one exploits the full fields measured by the DIC, whereas the second one exploits the experimental load–displacement curves along with FEM analysis. The DIC methodology was experimentally validated and proposed as an alternative method to evaluate the J-integral. It is especially suited for conditions in which it is not possible to use the conventional LDC method due to complex and possibly unknown loading conditions. Furthermore, results showed that the AM technique could be used effectively to induce cracks in this type of material. These two aspects together can lead to both a simplification of the fracture characterization process and to the possibility of dealing with a wider number of practical, real-world scenarios. Indeed, because of the nature of the additive manufacturing process, AM crack-like notches can be sintered even having complex geometry, being three-dimensional and/or inside the tested structure.
Tommaso Brugo; Ivo Campione; Giangiacomo Minak. Investigation by Digital Image Correlation of Mixed-Mode I and II Fracture Behavior of Polymeric IASCB Specimens with Additive Manufactured Crack-Like Notch. Materials 2021, 14, 1084 .
AMA StyleTommaso Brugo, Ivo Campione, Giangiacomo Minak. Investigation by Digital Image Correlation of Mixed-Mode I and II Fracture Behavior of Polymeric IASCB Specimens with Additive Manufactured Crack-Like Notch. Materials. 2021; 14 (5):1084.
Chicago/Turabian StyleTommaso Brugo; Ivo Campione; Giangiacomo Minak. 2021. "Investigation by Digital Image Correlation of Mixed-Mode I and II Fracture Behavior of Polymeric IASCB Specimens with Additive Manufactured Crack-Like Notch." Materials 14, no. 5: 1084.
This work investigates the fracture behavior of maraging steel specimens manufactured by the selective laser sintering (SLS) technology, in which a crack-like notch (sharp notch) was directly produced during the additive manufacturing (AM) process. For the evaluation of the fracture toughness, the inclined asymmetrical semi-circular specimen subjected to three points loading (IASCB) was used, allowing to cover a wide variety of Mode I and II combinations. The effectiveness of manufacturing crack-like notches via the SLS technique in metals was evaluated by comparing the obtained experimental results with the ones obtained with pre-cracks induced by fatigue loading. The investigation was carried out by using the digital image correlation (DIC) technique, that allowed the evaluation of the full displacement fields around the crack tip. The displacement field was then used to compute the stress intensity factors (SIFs) for various combinations of Mode I and II, via a fitting technique which relies on the Williams’ model for the displacement. The SIFs obtained in this way were compared to the results obtained with the conventional critical load method. The results showed that the discrepancy between the two methods reduces by ranging from Mode I to Mode II loading condition. Finally, the experimental SIFs obtained by the two methods were described by the mixed mode local stress criterium.
Ivo Campione; Tommaso Maria Brugo; Giangiacomo Minak; Jelena Janković Tomić; Nebojša Bogojević; Snežana Ćirić Kostić. Investigation by Digital Image Correlation of Mixed Mode I and II Fracture Behavior of Metallic IASCB Specimens with Additive Manufactured Crack-Like Notch. Metals 2020, 10, 400 .
AMA StyleIvo Campione, Tommaso Maria Brugo, Giangiacomo Minak, Jelena Janković Tomić, Nebojša Bogojević, Snežana Ćirić Kostić. Investigation by Digital Image Correlation of Mixed Mode I and II Fracture Behavior of Metallic IASCB Specimens with Additive Manufactured Crack-Like Notch. Metals. 2020; 10 (3):400.
Chicago/Turabian StyleIvo Campione; Tommaso Maria Brugo; Giangiacomo Minak; Jelena Janković Tomić; Nebojša Bogojević; Snežana Ćirić Kostić. 2020. "Investigation by Digital Image Correlation of Mixed Mode I and II Fracture Behavior of Metallic IASCB Specimens with Additive Manufactured Crack-Like Notch." Metals 10, no. 3: 400.
Three-dimensional thermography is a recent technique—with various fields of application—that consists of combining thermography with 3D spatial data in order to obtain 3D thermograms, high information objects that allow one to overcome some limitations of 2D thermograms, to enhance the thermal monitoring and the detection of abnormalities. In this paper we present an integration methodology that can be applied to merge data acquired from a generic thermal camera and a generic laser scanner, and has the peculiarity of keeping the two devices completely decoupled and independent, so that thermal and geometrical data can be acquired at different times and no rigid link is needed between the two devices. In this way, the stand-alone capability of each device is not affected, and the data fusion is applied only when necessary. In the second part, the real effectiveness of our approach is tested on a 3D-printed object properly designed. Furthermore, one example of an application of our methodology in the cultural heritage field is presented, with an eye to preservation and restoration: the integration is applied to a marble statue called Madonna with the Child, a fine work of the Florentine sculptor Agostino di Duccio (1418–1481). The results suggest that the method can be successfully applicable to a large set of scenarios. However, additional tests are needed to improve the robustness.
Ivo Campione; Francesca Lucchi; Nicola Santopuoli; Leonardo Seccia. 3D Thermal Imaging System with Decoupled Acquisition for Industrial and Cultural Heritage Applications. Applied Sciences 2020, 10, 828 .
AMA StyleIvo Campione, Francesca Lucchi, Nicola Santopuoli, Leonardo Seccia. 3D Thermal Imaging System with Decoupled Acquisition for Industrial and Cultural Heritage Applications. Applied Sciences. 2020; 10 (3):828.
Chicago/Turabian StyleIvo Campione; Francesca Lucchi; Nicola Santopuoli; Leonardo Seccia. 2020. "3D Thermal Imaging System with Decoupled Acquisition for Industrial and Cultural Heritage Applications." Applied Sciences 10, no. 3: 828.
Although large-sized ceramic slabs have become a common market product nowadays, their finishing processes still lack proper analyses and optimizations. The finishing is carried out on energy-consuming polishing machines by a train of rotating abrasive heads, which oscillates in a transverse direction on translating slabs. In this paper, a computational method able to investigate the effect of the kinematics on the texture distribution is proposed. Its algorithms allow to map the number of contacts and the scratching angles, relevant factors in the definition of the polished surface quality, but also, differently from the previous studies, the easy use of any preferred law of motion. After validation, the method is applied to a traditional polishing machine in order to assess the optimal process parameters as the forward motion of the conveyor belt and the transverse oscillation of the beam carrying the rotating head with the fickerts. An enhancement in terms of surface quality and machining process is evident. In particular, results suggest to adopt a specific frequency value for the transverse motion, nearly the half of the original one: in spite of a very similar texture, a significant reduction of energy is permitted. Finally, the optimization of motions and processes may lead to other general benefits, such as a reduction of the tool wear and mitigation of possible issues as mechanical vibrations or noise.
Ivo Campione; Cristiano Fragassa; Alberto Martini. Kinematics optimization of the polishing process of large-sized ceramic slabs. The International Journal of Advanced Manufacturing Technology 2019, 103, 1325 -1336.
AMA StyleIvo Campione, Cristiano Fragassa, Alberto Martini. Kinematics optimization of the polishing process of large-sized ceramic slabs. The International Journal of Advanced Manufacturing Technology. 2019; 103 (1-4):1325-1336.
Chicago/Turabian StyleIvo Campione; Cristiano Fragassa; Alberto Martini. 2019. "Kinematics optimization of the polishing process of large-sized ceramic slabs." The International Journal of Advanced Manufacturing Technology 103, no. 1-4: 1325-1336.