Dynamic increase factor (DIF) for concrete in compression and tension in FE modelling with a local concrete model

•Two DIF-ε˙ curves for concrete compressive and tensile global DIF effects are chosen based on existing SHPB test data.•The compression DIF is a structural effect and no DIF should be included in FE modelling at meso‑scale with a local concrete damage model.•For concrete in tension, the DIF is a gen...

Full description

Saved in:
Bibliographic Details
Published in:International journal of impact engineering 2022-05, Vol.163, p.104079, Article 104079
Main Authors: Li, Xiao-qin, Chen, Qian-jun, Chen, Jian-Fei, Liao, Jun-zhi, Lu, Yong
Format: Article
Language:English
Subjects:
Concrete
DIF (dynamic increasing factor)
Finite element method
Impact tests
Local concrete model
Mathematical models
Mesh & rate dependence
Strain rate
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Two DIF-ε˙ curves for concrete compressive and tensile global DIF effects are chosen based on existing SHPB test data.•The compression DIF is a structural effect and no DIF should be included in FE modelling at meso‑scale with a local concrete damage model.•For concrete in tension, the DIF is a genuine material property.•The commonly adopted empirical tensile global DIF-ε˙ curves are not suitable for direct application in FE analysis without discrimination.•A “doubly-corrected” (mesh and rate) local DIF-ε˙ relationship is proposed and validated for FE applications. The dynamic increase factor (DIF) in the strength of concrete-like materials has been a subject of extensive investigation and debate for many years. It now tends to be generally accepted that the compression DIF as observed from standard sample tests is mainly attributable to the dynamic structural effect, whereas for concrete under tension the DIF is deemed to be governed by different mechanisms, probably more from the material and micro-fracture level. This paper presents a numerical study on the uniaxial compression and tension DIF, with a particular focus on how the DIF, irrespective of its cause, should be included in an appropriate manner in the finite element (FE) modelling with a local concrete model. The inevitable mesh-dependency issue due to numerical localisation and its implications on rate effects are examined in detail. A mesh-objective modification on the standard sample tested tension DIF is proposed with the aim to achieve relatively mesh independent analysis in the FE models where high strain-rate tension is involved. The results demonstrate that the proposed approach is effective, and reliable modelling results can be achieved with the proposed DIF modelling scheme for the local concrete model.
ISSN:0734-743X
1879-3509
DOI:10.1016/j.ijimpeng.2021.104079