ASTM WK94258
New Test Method for Standard Test Method for Uniaxial Constant Force Repeated Thermal Cycling of Shape Memory Alloys
1. Scope
1.1 This test method defines procedures for repeated thermal cycling of shape memory alloy (SMA) materials and components under constant force through partial or full phase transformation. This method measures the effect of repeated thermal cycling under constant force on transformation properties, accumulated strain, residual strain, strain evolution, and functional and structural fatigue. This test is done to provide data for material design, quality control, the selection of shape memory alloy materials, design allowables, actuator design, and failure analysis. 1.2 The objective of this test method is to assess the ability of SMA material and components to meet life expectancy requirements in an actuator application. Life expectancy requirements may include structural and/or functional fatigue limits, as defined in this test method.Keywords
shape memory alloy; NiTi; Nitinol; actuation; fatigue; phase transformationRationale
A broad range of potential applications for exist for Shape Memory Alloy (SMA) based actuators, however their transition from prototype demonstration to production and commercial use is hindered by the lack of accepted industry and regulatory testing and certification standards. Approved test methods are needed to support the development of design allowables, supplier qualification, and regularity approval of SMA materials and components. A committee was formed with members from industry, government and academia to develop and publish standard test methods that are specifically intended to measure SMA actuation properties. The committee was organized within the Aviation Vehicle Systems Institute (AVSI). Under this committee standard test methods for Uniaxial Constant Force Thermal Cycling (UCFTC) and Uniaxial Pre-strain and Free Recovery (UPFR) were published in coordination with ASTM as E3097 and E3098, respectively. In light of this recent development additional test methods are still needed to fully support the transition of SMA actuators to production use. Here, there is a recognized need for a test method that defines and evaluates dimensional stability, the evolution of actuation properties and actuation lifecycles during repeated UCFTC.
Work Item Status
Date Initiated: 03-20-2025
Technical Contact: Douglas Nicholson
Item: 000
Ballot:
Status: