Experimental investigation of the influence of the heating rate in an SMA actuator performance

• Experimental tests of shape memory alloys.
• Analysis of rate dependent behavior of shape memory alloys.
• Actuator displacement and force maximization by heating rate.
• Actuator energy efficiency.

The use of shape memory alloys (SMAs) as actuators has an increasing importance in several areas. In general, the shape memory effect and the two-way shape memory effect are employed in order to produce displacements and/or forces by heating the SMA actuator above the phase transformation temperature. This paper presents an experimental investigation on the heating rate influence on an SMA actuator. Basically, an experimental apparatus is built by considering NiTi wire connected to a steel spring and monitored by sensors. The heating rate varies from 2.9 °C/min to 385 °C/min by applying an electrical current in the SMA actuator. Several situations are investigated highlighting the general thermomechanical behavior associated with the influence of heating rate.