Numerical study of the compressive behavior of concrete material at high strain rate with active confinement

2019 ◽  
Vol 22 (10) ◽  
pp. 2359-2372
Author(s):  
Zhicheng Ye ◽  
Yifei Hao ◽  
Hong Hao
2015 ◽  
Vol 55 (5) ◽  
pp. 935-950 ◽  
Author(s):  
H. Luo ◽  
Y. Du ◽  
Z. Hu ◽  
W. L. Cooper ◽  
H. Lu

Author(s):  
Ericka K. Amborn ◽  
Karim H. Muci-Küchler ◽  
Brandon J. Hinz

Studying the high strain rate behavior of soft tissues and soft tissue surrogates is of interest to improve the understanding of injury mechanisms during blast and impact events. Tests such as the split Hopkinson pressure bar have been successfully used to characterize material behavior at high strain rates under simple loading conditions. However, experiments involving more complex stress states are needed for the validation of constitutive models and numerical simulation techniques for fast transient events. In particular, for the case of ballistic injuries, controlled tests that can better reflect the effects induced by a penetrating projectile are of interest. This paper presents an experiment that tries to achieve that goal. The experimental setup involves a cylindrical test sample made of a translucent soft tissue surrogate that has a small pre-made cylindrical channel along its axis. A small caliber projectile is fired through the pre-made channel at representative speeds using an air rifle. High speed video is used in conjunction with specialized software to generate data for model validation. A Lagrangian Finite Element Method (FEM) model was prepared in ABAQUS/Explicit to simulate the experiments. Different hyperelastic constitutive models were explored to represent the behavior of the soft tissue surrogate and the required material properties were obtained from high strain rate test data reported in the open literature. The simulation results corresponding to each constitutive model considered were qualitatively compared against the experimental data for a single projectile speed. The constitutive model that provided the closest match was then used to perform an additional simulation at a different projectile velocity and quantitative comparisons between numerical and experimental results were made. The comparisons showed that the Marlow hyperelastic model available in ABAQUS/Explicit was able to produce a good representation of the soft tissue surrogate behavior observed experimentally at the two projectile speeds considered.


2017 ◽  
Vol 8 (2) ◽  
pp. 155-176 ◽  
Author(s):  
Xiangzhen Kong ◽  
Qin Fang ◽  
Hao Wu ◽  
Jian Hong

High strain-rate induced from intense dynamic loadings will cause an obvious enhancement of concrete material frequently used in civil and defense engineering, which plays an important role in correct numerical simulations of concrete members subjected to intense dynamic loadings. In this article, the existing three strain-rate enhancement approaches for concrete material are compared by three aspects, that is, flexibility of fitting data, consistency condition, and time-dependent behavior. The so-called “overstress approach” is found to be not flexible for fitting high strain-rate data and unable to well predict the strain-softening behavior but can capture the inherent viscidity of concrete material. The “consistency approach” can describe the strain-softening behavior and the inherent viscidity but may be inconvenient and time-consuming when fitting high strain-rate data. The “simplified approach” widely used in commercial concrete material models can describe the strain-softening behavior and fit high strain-rate data by a more convenient and direct way but cannot capture the inherent viscidity of concrete material. Examples of uniaxial stress including loading and unloading under constant and varying strain-rates are presented to demonstrate the above-mentioned findings, in which the updating algorithm of dynamic stress is presented in detail.


2018 ◽  
Vol 276 ◽  
pp. 140-147
Author(s):  
Martina Drdlová ◽  
Miloslav Popovič ◽  
René Čechmánek

This paper presents an experimental study on the high strain rate compressive behavior of micro-fibre reinforced ultrahigh performance cementitious composite, which is intended to be used as a matrix for slurry infiltrated fibre concrete (SIFCON). Cementitious composite specimens with 5 different types of microfibres, namely aramid, carbon, wollastonite, polypropylene and glass in amounts of 1.5-2.0% by volume were prepared and investigated. Split Hopkinson pressure bar (SHPB) equipment was used to determine the cementitious composite behavior at strain rates up to 1600 s-1. Quasistatic tests were performed, as well and ratios of these properties at high strain rates to their counterparts at static loading were compared. The dynamic increase factors were calculated. Strain rate sensitivity was observed - compressive strength was found to be increased with strain rate for all tested specimens. Peak stress values, critical compressive strain and post peak behaviour varies for specimens with different micro-fibre reinforcement, which allows to find the optimal reinforcement for high strain rate impacted structures.


2011 ◽  
Vol 82 ◽  
pp. 57-62 ◽  
Author(s):  
Sha Sha Wang ◽  
Min Hong Zhang ◽  
Ser Tong Quek

This paper presents a laboratory experimental study on the effect of high strain rate on compressive behavior of plain and fiber-reinforce high-strength concrete (FRHSC) with similar strength of 80-90 MPa. Steel fibers, polyethylene fibers, and a combination of these were used in the FRHSC. A split Hopkinson pressure bar equipment was used to determine the concrete behavior at strain rates from about 30 to 300 s-1. The ratio of the strength at high strain rates to that at static loading condition, namely dynamic increase factor (DIF), of the concretes was determined and compared with that recommended by CEB-FIP code. Fracture patterns of the specimens at high strain rates are described and discussed as well. Results indicate that the CEB-FIP equation is applicable to the plain high strength concrete, but overestimates the DIF of the FRHSC at strain rates beyond a transition strain rate of 30 s-1. Based on the experimental results, a modified equation on DIF is proposed for the FRHSC.


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