The ultimate goal of our research is to develop a bone transport device using a magnetostrictive alloy actuation system. The device is designed to be subcutaneously mounted on the periosteal surface of the tibia. The magnetomechanical behavior of Terfenol-D smart magnetostrictive material has been well investigated in the literature when a magnetic field is applied along the longitudinal direction of the Terfenol-D material (perpendicular to the material’s magnetic moment). However, the requirement of our device is to have the magnetic field transversely applied on the Terfenol-D material (along the material’s magnetic moment). Therefore, the objective of this work was to study the magnetomechanical behavior of Terfenol-D under a transversely applied magnetic field. Experimental work was performed and a Terfenol-D material constitutive behavior was investigated.