NUMERICAL AND EXPERIMENTAL STUDY OF SHAPE EFFECT BEHAVIOR OF NITINOL WIRE

Abstract

The aim of this research, returned NiTinol wire to original length by activation. The experimental test and ANSYS v15 software were conducted to study the shape memory effect behavior for NiTinol wire has high temperature about 80°C±10°C. Full annealing of NiTinol wire was employed with a straight shape, this alloy it consists of (Ni-55%, H-0.001%, 0-0.05%, N-0.001%, C-0.05% and Ti-Balance). In this research, a NiTinol wire was implemented (2 mm diameter) and (100 mm length). The experimental results and ANSYS software were almost near. Shape memory effect data constants used in ANSYS software were extracted from the experimental test by applying linear interpolation. These data were hardening parameter (C1) about 900 MPa and elastic limit (C3) about 30 MPa. These data were temperature scaling parameter C4=0.89, maximum transformation strain C5=0.074%, martensite modulus C6=20000 MPa and dependency parameter C7=0. The amount of strain (7 %) applied in this test returned to zero after activation NiTinol wire, and that gives an indication that the permanent deformation is decline. The start austenite temperature (As) was about 58°C and finish austenite temperature (Af) was about 70°C . ANSYS software provided good results when compared with the experimental work.