A numerical assessment of strain rate effects on the critical state of crushable granular materials

2022 ◽  
Vol 12 (1) ◽  
pp. 1-19
Author(s):  
S.K. Das ◽  
S.K. Verma ◽  
A. Das

The present study highlights the effects of strain rate on the critical state response of crushable granular materials. A set of drained triaxial tests is simulated using the discrete element method (DEM) to understand the rate effects on the stress-strain and volumetric behaviour of the granular sample. The DEM parameters are obtained by comparing the stress-strain and particle crushing behaviour of in-house experimental analysis on crushable coral sand under a slow strain rate. In DEM, the particles are subjected to varied strain rates under different initial confining pressures and initial densities to capture the rate effects on the macroscopic responses until the critical state. It is seen that crushing increases with increasing confining stress. However, a higher strain rate induces relatively lower crushing and higher strength in terms of both peak stress and residual stress. It is observed that in pressure-volume space, the critical state line alters with the increasing strain rate of the crushable samples, especially at high confining conditions, whereas strain rate effect on critical state seems to be negligible at low confining conditions due to the absence of particle crushing.

2007 ◽  
Vol 539-543 ◽  
pp. 3619-3624 ◽  
Author(s):  
K. Ogawa

Since titanium alloys are the most promising structural materials for the high velocity vehicles, the impact tensile strength of the materials is presently investigated. Three kinds of aging treatments on the beta-titanium alloy were performed, and the tensile deformation behaviors were identified in the wide range of the temperature and the strain rate. The stress-strain relations of the titanium alloy significantly depend on the temperature and the strain rate investigated. Thermally activated process concept was applied to explain the experimental results, and the stress-strain relations at high strain rates were well understood with taking account of adiabatic heating effect. It has been found that the stress-strain curves depend on the microstructures, while the temperature and the strain rate effects are almost independent of the different aging treatments.


2017 ◽  
Vol 17 (5) ◽  
pp. 04016115 ◽  
Author(s):  
Wei-Qiang Feng ◽  
Jian-Hua Yin ◽  
Xiao-Ming Tao ◽  
Fei Tong ◽  
Wen-Bo Chen

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