PEREIRA, F. F. R.; http://lattes.cnpq.br/2853417152559160; PEREIRA, Francisco Fernando Roberto.
Résumé:
In many situations, the bolts of a mechanical design are considered as having a
secondary importance, when in fact they have fundamental aspects of its operation,
once they are used within the loading limits established by the manufacturer. If not, the
bolts may failure through different manners. In order to solve or minimize these
problems associated with bolts, new materials have been studied, such as Shape
Memory Alloys (SMA). Such alloys belong to the class of active materials and have the
surprising ability to recover an "apparently plastic" strain through a subsequent heating
above a critical temperature. The application of these materials has increased on many
fields, due to the special properties of these alloys (Shape memory, superelasticity and
others). In this context, a possible alternative to minimize or even eliminate the
drawbacks associated with conventional bolts would be manufacturing these elements
from SMA. In this regard, the main objective of this work was to manufacture and test
bolts made of SMA from NiTi-system. The tests aimed to analyze the behavior of SMA
bolts from the viewpoint of Shape Memory Effect (SME), Superelasticity (SE), and
Transverse Cyclic Shear (TCS). Thus, to analyze the effects of many factors on the
response variable, some of the tests were carried out according to a methodology of
Design of Experiments (DOE). Based upon the results, one can establish that the SMA
bolts have a strong application potential and, in this way, it was possible to attest the
innovative nature of this work, which might be the basis for future studies on the field
of SMA fasteners.
