Authors:C. Auguet, A. Isalgué, F. Lovey, F. Martorell, and V. Torra
The behavior of shape memory alloys (SMA) allows their use as a passive
smart material. In particular, the existence of a hysteretic cycle in the
domain of the elementary coordinates strain-stress-temperature (σ, ε, T) suggests its application for damping
in mechanical and/or in civil engineering. We are working in the application
of SMA as dampers for earthquakes in small houses as family homes. For dampers
installed in the inner porticos of the house, the suggested SMA is the CuAlBe
and, eventually, the NiTi. At room temperature the used SMA wires induces
forces situated between 2–3kN/wire. The properties related with the
damping applications for CuAlBe and NiTi, i.e., the SMA creep and the self-heating
will be presented, together with some other minor stress and temperature effects
on NiTi modifying the hysteretic behavior.
Authors:G. Carreras, A. Isalgue, V. Torra, F. Lovey, and H. Soul
The fatigue-life (traction-traction only) is experimentally studied mainly for pseudoelastic NiTi wire of 2.46 mm of diameter
for eventual application in damping of structures under wind or rain. Thermal effects are highly relevant in determining the
fatigue-life. The results shows that the fracture level overcomes 130000 cycles when the moving air is used for cooling. When
the number of working cycles overcomes 30000, the frictional energy decreases 40% vs. N roughly with an exponential behavior.
Authors:Richard DV. Espiritu and Alberto V. Amorsolo Jr.
Shape memory alloys (SMA) are metallic materials that undergo thermoelastic martensiticphasetransformation which demonstrates their ability to return to some previously defined shape when subjected to an