Importance of dynamics in small scale mechanical testing: Fast constant strain rate and ballistic testing

摘要

Recent advances in electronics have enabled nanomechanical measurements with very low noise levels at fast time constants and high data acquisition rates. Nanomechanical testers with sub-nanometer noise levels at a displacement time constant of 20μsare currently available which open the doors for a wide range of ultra-fast nanomechanical testing. It not only enables accurate measurement of materials' response during a dynamic event such as strain burst (pop-in) during micropillar or indentation testing, but also enables fast indentation tests. However, fast testing requires a precise understanding of the instrument's dynamic response along with the time constants of the measurement signals.