Article
Materials Science, Multidisciplinary
Puneeth Jakkula, Georg Ganzenmueller, Stefan Hiermaier
Summary: This study introduces a variation of the Hopkinson bar, called Direct Impact Tension Bar (DITB), which is well-suited for probing low-impedance materials at intermediate strain-rates. The DITB offers accurate force signals without detrimental oscillations, making it a reliable tool for studying strain-rate effects. Experimental results on polycarbonate specimens demonstrate the applicability of the DITB in dynamic tensile tests, providing high-quality data free from oscillations.
Review
Chemistry, Physical
Kamil Sobczyk, Ryszard Chmielewski, Leopold Kruszka, Ryszard Rekucki
Summary: The paper presents a review of crucial experiments and the latest publications on soil dynamic interaction using the Hopkinson bar technique from 2018 to 2021. The study found that the dynamic response of the soil is affected by factors such as density, cohesion, moisture, and grain structure. Further research is still needed in the field of SHPB experiments under modified conditions and a wide range of strain rates. Understanding the characteristics of different types of soil is emphasized for selecting structural design solutions for critical infrastructure.
Article
Engineering, Mechanical
Chenlin Liu, Xue Yang, Yi Ding, Haodong Li, Siqi Wan, Yazhou Guo, Yulong Li
Summary: In this paper, dynamic tension-torsion tests are performed using a newly developed C-THB system, and the initial yielding envelopes at different strain rates are revealed for the first time. Tresca, von Mises, and Hill yield criterion are established and evaluated, and a universal model describing the strain rate hardening of material under complex stress states is proposed. A modified Hill yield criterion for pure copper (TU00) is deduced based on this model, which fits well with the experimental yielding envelope at different strain rates.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Forestry
Mojtaba Hassan Vand, Jan Tippner
Summary: This article investigates the impact bending strength of different wood species after thermal-modification. The results show that thermal-modification significantly reduces the deflection and maximum longitudinal strain of the wood, resulting in a decrease in impact bending strength. However, at 180 degrees C, the impact bending strength does not exhibit a significant decrease.
Article
Engineering, Mechanical
Yu Qiao, Yan Chen, Fu-Hua Cao, Hai-Ying Wang, Lan-Hong Dai
Summary: This paper reveals the unusual simultaneous strength-plasticity enhancement and high strain rate embrittlement inhibition of CrMnFeCoNi HEA in impact tension through split Hopkinson tensile bar (SHTB) testing and high-speed photography. Microstructural analysis shows that the cooperation of twins and dislocations is the crucial mechanism for the synchronous enhancement of strength-plasticity in this alloy under impact tension. A thermo-viscoplastic constitutive model based on dislocations and twins evolution was developed to describe the dynamic mechanical behavior of HEAs at high strain rates.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2021)
Article
Materials Science, Characterization & Testing
H. He, Q. Deng, C. X. Wang, J. Li, K. X. Weng, Y. G. Miao
Summary: A methodology was proposed to achieve large strains under intermediate strain rates, with an experimental system constructed based on it. The system includes a striker bar generating continuous stress wave loading and a long polymethylmethacrylate bar as the transmitted bar, allowing for nearly constant amplitude loading stress wave with infinite duration. The measurement capacity was confirmed through loading a thermoplastic polyurethane with maximum strains up to 12% and 65% under different strain rates.
Article
Engineering, Geological
Zhiwu Zhu, Tiantian Fu, Zhiwei Zhou, Chenxu Cao
Summary: This study investigated the dynamic characteristics of frozen soil with a water content of 20% and different freezing temperatures under the impact of a spilt Hopkinson pressure bar in cold area construction. The results showed that the improved nonlinear model can accurately describe the impact mechanics of frozen soil and predict the evolution law of typical mechanical indexes.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Mechanical
Yifei Meng, Yuting Yang, Weibin Wang, Qingbo Dou, Tao Suo
Summary: This study developed an improved high-temperature dynamic torsion experimental method for determining the shear mechanical properties of materials under the coupling effect of high strain rates and high temperatures. By optimizing the specimen design and strain measurement correction method, the accuracy and reliability of the tests were improved. Experimental results demonstrated the suitability of this method for strain rate testing at different temperatures.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
Longhui Zhang, David Townsend, Nik Petrinic, Antonio Pellegrino
Summary: This paper investigates the dynamic compressive behavior and failure of PA66-GF30 under uniaxial and multiaxial loading at different strain rates and temperatures. The material shows pressure sensitivity and exhibits micro cracks and macro strain localization after reaching maximum stress under high strain rate loading. Confined PA66-GF30 experiences adiabatic shear failure while unconfined material shows fiber pull-out in the fractured matrix. A modified Drucker-Prager model is proposed to describe the pressure-dependent compressive strength of PA66-GF30 under various conditions.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Engineering, Mechanical
Yifei Meng, Yuting Yang, Weibin Wang, Qingbo Dou, Tao Suo
Summary: An improved high-temperature dynamic torsion experimental method was developed in this study, utilizing an electromagnetic torsional Hopkinson bar equipped with a special system and proposing a double-flange thin-walled tubular specimen, achieving online heating and synchronous assembly successfully. This provides a new approach for studying the shear mechanical properties of materials under high strain rates and high temperatures.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
Mostafa Hassan, Kay Wille
Summary: This paper investigates the dynamic tensile behavior of steel fiber reinforced ultra-high performance concrete (SF-UHPC) under impact loading. The study designs a modified split Hopkinson tensile bar (SHTB) to obtain the dynamic behavior of SF-UHPC with different fiber volume fractions. The results provide average dynamic impact factors and suggest an equation to calculate the DIF of the tensile strength of SF-UHPC.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Construction & Building Technology
Yijiao Huang, Xianfeng Wang, Min Sheng, Dawei Qin, Jun Ren, Xiaoqing Zhou, Jihua Zhu, Feng Xing
Summary: This study investigated the dynamic behavior of microcapsule-based self-healing concrete under impact loading. It found that the dynamic mechanical properties of the self-healing concrete exhibit strong strain-rate dependency, with compressive strength and strain energy density increasing with increasing strain rate. Significant differences in post-test damage patterns were observed between control and experimental groups. The dynamic increase factor (DIF) of the self-healing concrete increases logarithmically with strain rate, with a strain-rate sensitivity threshold at 25.7 s(-1). Empirical DIF relations were proposed for predicting material behavior under static and impact loading.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Multidisciplinary
Shady Salem, Elamir Eissa, Eman Zarif, Sarah Sherif, Mostafa Shazly
Summary: This research experimentally assesses the compressive strain rate effects of concrete at different saturation levels and introduces calibration factors to account for the degree of saturation. The proposed calibrated equation shows more reliable predictions than the current equation used in the literature.
AIN SHAMS ENGINEERING JOURNAL
(2023)
Article
Construction & Building Technology
Chengjun Yue, Li Chen, Jiayi Yuan, Qiyao Li, Linfeng Xu
Summary: Using the split Hopkinson pressure bar (SHPB), the existing method for calculating the splitting tensile strain rate of a Brazilian disk test only considers the influence of tensile stress, leading to a large error compared to the actual measurement due to the combined effect of compressive stress and tensile stress. To address this issue, a new analytical method considering tension-compression coupling was proposed, which showed highly consistent results with numerical calculations and experiments. The existing method overestimates the strain rate and can lead to dangerous engineering design.
MATERIALS AND STRUCTURES
(2023)
Article
Engineering, Civil
Yang Cai, Hui-qi Ren, Zhi-lin Long, Rui-qi Guo, Kuang-min Du, Sha-sha Chen, Zhi-hao Zheng
Summary: This study investigates the dynamic mechanical properties of coral aggregate concrete (CAC) and compares it with ordinary Portland cement concrete (OPC). The results show significant differences between CAC and OPC in terms of failure pattern, particle evolution, and dynamic increase factor under high strain rate loading. Additionally, CAC exhibits a brittle-ductile transition under dynamic loading, with lower impact toughness and energy absorption capacity compared to OPC.
