Pulse Shaper and Dynamic Compressive Property Investigation on Ice Using a Large-Sized Modified Split Hopkinson Pressure Bar

Abstract

The dynamic compressive behavior of ice is investigated using a large-sized (37 mm in diameter) modified aluminum split Hopkinson pressure bar (SHPB) with pulse shaper at the strain rate from 500 s -1 to 1200 s -1 . A series of relatively stable experimental results of dynamic compressive strength versus strain rate and a linear fitting curve have been obtained by controlling data scatter within 25%. The composition of incident wave has been discussed. The effects of pulse shaper diameter and velocity of striker bar have been tested. The properties and principles of incident wave in different stage has been elaborated when using pulse shaper. A theoretical analysis of pulse shaper and bar size effects on the rising time of incident wave has been conducted. Results show the thickness of pulse shaper is proportional to the rising time. Enlarging the diameter and reducing the velocity of the striker bar could increase the rising time and suppress the dispersion. The diameter and wave impedance of bars also contribute to the rising time.

Effect of strain rates on the mechanical response of whole muscle bundle

“…However, the transmission signal of soft biological materials is very weak. To solve this problem, the transmitted bar is a hollow rod with an inner diameter of 18 mm [21,22]. The striker bar is connected to a pneumatic cylinder, and its movement generates a collision between the striker and incident bars.…”

“…In addition, a hollow transmitted bar solved the problem that the waves on the transmitted bar were too weak as mentioned above. The transmitted pulse passing through the hollow bar created an ampli ed strain signal, which the sensors could measure easily [21,22]. It was noted that, unliked experiments at quasi-static strain rate, the recorded strain ranges were smaller.…”

Problems Associated with Making Mechanical Measurements on Water–Ice at Quasistatic and Dynamic Strain Rates

“…One way of achieving this is to increase the rise time of the loading pulse by placing a piece of copper shim on the impact end of the input bar ( Fig. 8) [24,25,[74][75][76][77]. We used colloidal graphite lubricant paste to attach the shim to the bar end.…”

In-Situ Damage Evaluation of Pure Ice under High Rate Compressive Loading

“…One of the main questions related to this kind of work is whether ice exhibits strain rate sensitivity at high rates of loading. There are published reports [4,5,6,7,8] on the measurement of the high strain rate properties of ice using the Split Hopkinson Bar method, which is a well-established technique for the measurement of material responses in the strain rate region of 100 s −1 to 10,000 s −1 [9]. These previous works have concentrated on measuring the strain rate sensitivity of the maximum strength of ice and the analysis has been mainly carried out based on the measured macroscopic stress-strain curves.…”