scholarly journals Dynamic Mechanical Behavior and Numerical Simulation of Frozen Soil under Impact Loading

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Dan Zhang ◽  
Zhiwu Zhu ◽  
Zhijie Liu
Keyword(s):  
Mechanical Behavior ◽  
Impact Loading ◽  
Dynamic Mechanical Properties ◽  
Frozen Soil ◽  
Element Analysis ◽  
Dynamic Mechanical ◽  
Dynamic Mechanical Behavior ◽  
The Finite Element Analysis ◽  
Split Hopkinson ◽  
Impact Experiments

Split Hopkinson pressure bars (SHBP) were used to perform impact experiments on frozen soil under various impact velocities and temperatures to analyze the effect of these parameters on the mechanical behavior of the soil. Based on the Holmquist-Johnson-Cook constitutive model, the dynamic mechanical properties under impact loading were analyzed. The SHPB experiments of frozen soil were also simulated using the finite element analysis software LS-DYNA, and the simulation results were similar to the experimental results. The temperature effect, strain rate effect, and the destruction process of the frozen soil as well as the propagation process of stress waves in the incident bar, transmission bar, and frozen soil specimen were investigated. This work provides a good theoretical basis and technical support for frozen soil engineering applications.

scholarly journals Development of a True-Biaxial Split Hopkinson Pressure Bar Device and Its Application

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7298
Author(s):  
Shumeng Pang ◽  
Weijun Tao ◽  
Yingjing Liang ◽  
Shi Huan ◽  
Yijie Liu ◽  
...  
Keyword(s):  
Stress Wave ◽  
Impact Loading ◽  
Split Hopkinson Pressure Bar ◽  
Axial Stress ◽  
Dynamic Mechanical Properties ◽  
Stress Waves ◽  
Hopkinson Pressure Bar ◽  
Dynamic Mechanical ◽  
Split Hopkinson ◽  
Pressure Bar

Although highly desirable, the experimental technology of the dynamic mechanical properties of materials under multiaxial impact loading is rarely explored. In this study, a true-biaxial split Hopkinson pressure bar device is developed to achieve the biaxial synchronous impact loading of a specimen. A symmetrical wedge-shaped, dual-wave bar is designed to decompose a single stress wave into two independent and symmetric stress waves that eventually form an orthogonal system and load the specimen synchronously. Furthermore, a combination of ground gaskets and lubricant is employed to eliminate the shear stress wave and separate the coupling of the shear and axial stress waves propagating in bars. Some confirmatory and applied tests are carried out, and the results show not only the feasibility of this modified device but also the dynamic mechanical characteristics of specimens under biaxial impact loading. This novel technique is readily implementable and also has good application potential in material mechanics testing.

Dynamic Mechanical Properties of Porous Rock under Impact Loading

2011 ◽  
Vol 228-229 ◽  
pp. 5-9
Author(s):  
Yong Xiang Dong ◽  
Chang Jing Xia ◽  
Li Xing Xiao ◽  
Shun Shan Feng
Keyword(s):  
Mechanical Behavior ◽  
Impact Loading ◽  
Split Hopkinson Pressure Bar ◽  
Rock Fracture ◽  
Wave Theory ◽  
Hopkinson Pressure Bar ◽  
Dynamic Mechanical ◽  
Dynamic Mechanical Behavior ◽  
Rock Porosity ◽  
The Impact

Dynamic impact experiments of man-made rock were carried out with the Split Hopkinson Pressure Bar (SHPB) apparatus in this paper. The impact process was analyzed and the influence of rock porosity on dynamic mechanical behavior was investigated. The stress-strain curves in rock were obtained by the one-dimensional stress wave theory. The curve lays foundation for numeric simulation of rock fracture under impact loading. The damage profiles of rock specimen under the impact loading show that the man-made rock exhibits obvious shear damage under the impact loading because it is a typical porous medium containing large quantities of defects such as pores, cracks and grain boundaries at the microscale. The experimental results also indicated that rock porosity plays an important role in dynamic mechanical behavior.

scholarly journals The Role of a Succinyl Fluorescein-Succinic Anhydride Grafted Atactic Polypropylene on the Dynamic Mechanical Properties of Polypropylene/Polyamide-6 Blends at the Polypropylene Glass Transition

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1216
Author(s):  
Jesús-María García-Martínez ◽  
Emilia P. Collar
Keyword(s):  
Glass Transition ◽  
Mechanical Behavior ◽  
Succinic Anhydride ◽  
Polyamide 6 ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Atactic Polypropylene ◽  
Agent Based ◽  
Dynamic Mechanical ◽  
Dynamic Mechanical Behavior

The present article adequately supports a twofold objective. On one hand, the study of the dynamic mechanical behavior of polypropylene/polyamide-6 blends modified by a novel compatibilizer was the objective. This was previously obtained by chemical modification of an atactic polypropylene polymerization waste. On the other hand, the accurate predictions of these properties in the experimental space scanned was the objective. As a novelty, this compatibilizer contains grafts rather than just maleated ones. Therefore, it consists precisely of an atactic polymer containing succinic anhydride (SA) bridges and both backbone and terminal grafted succinyl-fluorescein groups (SFSA) attached to the atactic backbone (aPP-SFSA). Therefore, it contains 6.2% of total grafting (2.5% as SA and 3.7% as SF), which is equivalent to 6.2 × 10−4 g·mol−1. This interfacial agent was uniquely designed and obtained by the authors themselves. Essentially, this article focuses on how the beneficial effect of both PA6 and aPP-SFSA varies the elastic (E’) and the viscous (E’’) behavior of the iPP/aPP-SFSA/PA6 blend at the iPP glass transition. Thus, we accurately measured the Dynamic Mechanical Analysis (DMA) parameters (E’, E’’) at this specific point considering it represents an extremely unfavorable scenario for the interfacial modifier due to mobility restrictions. Hence, this evidences the real interfacial modifications caused by aPP-SFSA to the iPP/PA6 system. Even more, and since each of the necessary components in the blend typically interacts with one another, we employed a Box–Wilson experimental design by its marked resemblance to the “agent-based models”. In this manner, we obtained complex algorithms accurately forecasting the dynamic mechanical behavior of the blends for all the composition range of the iPP/aPP-SFSA/PA6 system at the glass transition of iPP.

Dynamic Constitutive Model of Concrete

2012 ◽  
Vol 450-451 ◽  
pp. 379-382
Author(s):  
Wei Wu Yang ◽  
Hai Feng Liu ◽  
Jian Guo Ning
Keyword(s):  
Constitutive Model ◽  
Mechanical Behavior ◽  
Failure Criterion ◽  
Impact Loading ◽  
Experimental Results ◽  
Dynamic Mechanical ◽  
Criterion A ◽  
Dynamic Mechanical Behavior ◽  
Model Predictions

Based on the damage and Ottosen failure criterion, a dynamic constitutive model is proposed to investigate the mechanical behavior of concrete subjected to impact loading. The model predictions fit well with experimental results. So it can be used to simulate dynamic mechanical behavior of concrete

Dynamic mechanical behavior of different coral sand subjected to impact loading

2020 ◽  
pp. 095440622096768
Author(s):  
Kai Dong ◽  
Huiqi Ren ◽  
Wenjun Ruan ◽  
Kui Huang
Keyword(s):  
Mechanical Properties ◽  
Bulk Modulus ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Impact Loading ◽  
Dynamic Mechanical Properties ◽  
Rate Dependency ◽  
Dynamic Mechanical ◽  
Coral Sand ◽  
Strain Rate Dependency

The mechanical performance of coral sand exhibits significant variation due to the different physical properties of coral sand sampled from individual coral reefs. In this paper, a split Hopkinson pressure bar (SHPB) apparatus is used to conduct impact tests on two types of coral sand to investigate mechanical behavior. Using this approach, compressive stress-strain curves of the one-dimensional strain state are obtained, with strain rates ranging from 460 s−1 to 980 s−1. The results show that the internal porosity of particles is the main influence factor on strain rate dependency of coral sand subjected to impact loading. Various crushing patterns of the two coral sands will result in different strength performance and friction effects, directly creating variations in the dynamic mechanical properties of moist coral sand. Crushing patterns also have a significant influence on yielding stress and the bulk modulus of the pseudo-elastic response but have little effect on the bulk modulus after yielding. In this paper, the varying dynamic mechanical properties are analyzed on typical brittle coral sand by investigating the dominant crushing pattern of the two sand varieties. The conclusions obtained also provide insight into the strain rate dependency of quartz sand.

Dynamic Mechanical Behavior of Hybrid Flax/Basalt Fiber Polymer Composites

2021 ◽  
pp. 305-312
Author(s):  
Arun Prasath Kanagaraj ◽  
Amuthakkannan Pandian ◽  
Veerasimman Arumugaprabu ◽  
Rajendran Deepak Joel Johnson ◽  
Vigneswaran Shanmugam ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Polymer Composites ◽  
Basalt Fiber ◽  
Dynamic Mechanical ◽  
Dynamic Mechanical Behavior
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