Effect of Non-spherical Voids on the Mechanical Behavior of Shape Memory Alloys
The use of shape memory alloys has seen a steady increase since its discovery.
Understanding the mechanical behavior behind a ductile fracture of these materials
is important to further the applicability of shape memory alloys. Some research
on spherical microvoids in shape memory alloys has been conducted, but there is
not much literature on non-spherical voids.
The effect of non-spherical microvoids on the mechanical behavior of shape memory
alloys has been explored in this thesis. By running numerical simulations in
the commercial finite element software Abaqus, several different void shapes and
sizes were analyzed. The simulations were limited to uniaxial stress without superplasticity.
The results suggest that the width of the void, not the heigth/width
ratio or the void volume fraction, has the greatest influence on the transformation
stresses. Due to the limitations of this thesis, further studies should be conducted.
The results had some differences compared to similar studies. The nature of the
difference is unknown, and should be further explored. A more in-depth study
with more shapes and void volume fractions is also needed to confirm the findings
of this report. Both the effect of superplasticity, as well as a triaxial stress state
may produce different results. A study of the effect of superplasticity should be
emphasized, as plasticity is a very important part of a material?s behavior.
Place, publisher, year, edition, pages
Institutt for konstruksjonsteknikk , 2013. , 45 p.
IdentifiersURN: urn:nbn:no:ntnu:diva-22634Local ID: ntnudaim:8906OAI: oai:DiVA.org:ntnu-22634DiVA: diva2:650453
Zhang, Zhiliang, Professor