ISSN:
1662-7482
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The material assumptions made to facilitate Thermoelastic Stress Analysis (TSA) arelinear elasticity, material homogeneity and isotropy, and mechanical properties that are independentof temperature. The unusual shape memory and superelastic properties of near equiatomic NiTialloys complicate the application of any experimental stress analysis technique, and in the case ofTSA, make these assumptions invalid. This paper describes a detailed analysis conducted tocharacterise the material properties of NiTi shape memory alloys and to identify loading conditionssuitable for quantitative stress analysis using TSA. The mechanical behaviour of the material inthree distinct regions is considered and the suitability of each region for TSA is discussed. It isshown that the thermoelastic response is dependent on the mean stress when tested at roomtemperature in the pre-martensitic phase, due the presence of an intermediate R-phase. Theoreticalcalculations are used to confirm that this effect is related to the high temperature dependence of thematerial’s Young’s modulus
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMM.13-14.225.pdf
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