magneto strictive actuator has and active core of length L=20 mm. It is made of Terfenol D, a giant magneto strictive alloy of terbium, dysprosium and iron. If a field sufficiently large to saturate the core is applied, by how much will the core change in length? Use the mean value of the data for Terfenol D listed in Appendix A, Section A9, to find out.

Data From Appendix A9

Transcribed Image Text:

Table A.9 Magnetic, Magnetostrictive and Magnetocaloric Materials Hard Magnetic Materials Remanent Induction (T) Coercive Force (A/m) Max. Energy Product (MJ/m) Alnico Ferrites, hard 0.52-1.4 0.2-0.46 Neodymium iron boron 0.98-1.5 3600-6300 13,000-35,000 60,000-1,100,000 Samarium cobalt 0.78-1.2 33,000-82,000 9600-60,000 6400-41,000 190,000-180,000 110,000-250,000