Strain rate dependency of uniaxial tensile strength in Gosford sandstone by the Distinct Lattice Spring Model with X-ray micro CT

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:51

Article

Zhao, Gao-Feng¹  Russell, Adrian R.¹  Zhao, Xiaobao²  Khalili, Nasser¹ 

[1] Univ New S Wales, Ctr Infrastruct Engn & Safety, Sch Civil & Environm Engn, Sydney, NSW 2052, Australia

[2] Nanjing Univ, Sch Earth Sci & Engn, Nanjing 210093, Jiangsu, Peoples R China

关键词: Strain rate dependency;    Dynamic direct tensile strength;    Sandstone;    Distinct Lattice Spring Model;    X-ray micro CT;   

DOI  :  10.1016/j.ijsolstr.2014.01.012

来源: Elsevier

【 摘 要 】

Mechanisms causing strain rate dependency of the uniaxial tensile strength of Gosford sandstone are studied using the Distinct Lattice Spring Model (DLSM). The DLSM is built to have a microstructure which resembles aspects of the microstructure in a sample of the sandstone observed through 5 mu m resolution X-ray micro CT scanning. Numerical dynamic uniaxial tensile tests on the sandstone are performed using both X-ray micro CT based and homogenous particle models. The results indicate that there is an only negligible strength increase with increasing strain rate for the homogenous particle model. However, a significant strength increase is observed with increasing strain rate for the X-ray micro CT based particle model. Therefore, it must be the microstructure that causes a strain rate dependency. Moreover, the influence of viscosity and rate dependency of springs are also studied. Results reveal that the rate dependency of the springs rather than their viscosity is also a main cause of the rate dependency. (C) 2014 Elsevier Ltd. All rights reserved.

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