scholarly journals A Coupled Experiment-finite Element Modeling Methodology for Assessing High Strain Rate Mechanical Response of Soft Biomaterials

10.3791/51545 ◽  
2015 ◽  
Author(s):  
Rajkumar Prabhu ◽  
Wilburn R. Whittington ◽  
Sourav S. Patnaik ◽  
Yuxiong Mao ◽  
Mark T. Begonia ◽  
...  
Keyword(s):  
Finite Element ◽  
High Strain Rate ◽  
Finite Element Modeling ◽  
Strain Rate ◽  
Mechanical Response ◽  
High Strain ◽  
Element Modeling ◽  
Modeling Methodology ◽  
Soft Biomaterials

scholarly journals High-strain-rate mechanical response of HTPE propellant under SHPB impact loading

AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035145
Author(s):  
Heng-ning Zhang ◽  
Hai Chang ◽  
Jun-qiang Li ◽  
Xiao-jiang Li ◽  
Han Wang
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Impact Loading ◽  
Mechanical Response ◽  
High Strain

An Alternate Approach to SHPB Tests to Compute Johnson-Cook Material Model Constants for 97 WHA at High Strain Rates and Elevated Temperatures Using Machining Tests

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Chithajalu Kiran Sagar ◽  
Amrita Priyadarshini ◽  
Amit Kumar Gupta ◽  
Tarun Kumar ◽  
Shreya Saxena
Keyword(s):  
Finite Element ◽  
High Strain Rate ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
High Strain ◽  
Optimization Technique ◽  
Material Model ◽  
Computational Techniques ◽  
Fe Model

Abstract With advances in computational techniques, numerical methods such as finite element method (FEM) are gaining much of the popularity for analysis as these substitute the expensive trial and error experimental techniques to a great extent. Consequently, selection of suitable material models and determination of precise material model constants are one of the prime concerns in FEM. This paper presents a methodology to determine the Johnson-Cook constitutive equation constants (JC constants) of 97 W Tungsten heavy alloys (WHAs) under high strain rate conditions using machining tests in conjunction with Oxley’s predictive model and particle swarm optimization (PSO) algorithm. Currently, availability of the high strain rate data for 97 WHA are limited and consequently, JC constants for the same are not readily available. The overall methodology includes determination of three sets of JC constants, namely, M1 and M2 from the Split-Hopkinson pressure bar (SHPB) test data available in literature by using conventional optimization technique and artificial bee colony (ABC) algorithm, respectively. However, M3 is determined from machining tests using inverse identification method. To validate the identified JC constants, machining outputs (cutting forces, temperature, and shear strain) are predicted using finite element (FE) model by considering M1, M2, and M3 as input under different cutting conditions and then validated with corresponding experimental values. The predicted outputs obtained using JC constants M3 closely matched with that of the experimental ones with error percentage well within 10%.

scholarly journals Compressive Mechanical Properties of Porcine Brain: Experimentation and Modeling of the Tissue Hydration Effects

2019 ◽  
Vol 6 (2) ◽  
pp. 40 ◽  
Author(s):  
Raj K. Prabhu ◽  
Mark T. Begonia ◽  
Wilburn R. Whittington ◽  
Michael A. Murphy ◽  
Yuxiong Mao ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Water Content ◽  
Mechanical Response ◽  
High Strain ◽  
Peak Stress ◽  
Human Head ◽  
Element Analysis ◽  
Porcine Brain ◽  
Strain Behavior

Designing protective systems for the human head—and, hence, the brain—requires understanding the brain’s microstructural response to mechanical insults. We present the behavior of wet and dry porcine brain undergoing quasi-static and high strain rate mechanical deformations to unravel the effect of hydration on the brain’s biomechanics. Here, native ‘wet’ brain samples contained ~80% (mass/mass) water content and ‘dry’ brain samples contained ~0% (mass/mass) water content. First, the wet brain incurred a large initial peak stress that was not exhibited by the dry brain. Second, stress levels for the dry brain were greater than the wet brain. Third, the dry brain stress–strain behavior was characteristic of ductile materials with a yield point and work hardening; however, the wet brain showed a typical concave inflection that is often manifested by polymers. Finally, finite element analysis (FEA) of the brain’s high strain rate response for samples with various proportions of water and dry brain showed that water played a major role in the initial hardening trend. Therefore, hydration level plays a key role in brain tissue micromechanics, and the incorporation of this hydration effect on the brain’s mechanical response in simulated injury scenarios or virtual human-centric protective headgear design is essential.

Effects of hydrogen on the mechanical response of X80 pipeline steel subject to high strain rate tensile tests

2019 ◽  
Vol 43 (4) ◽  
pp. 684-697 ◽  
Author(s):  
Yuanyuan Zheng ◽  
Lin Zhang ◽  
Qiaoying Shi ◽  
Chengshuang Zhou ◽  
Jinyang Zheng
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Mechanical Response ◽  
High Strain ◽  
Pipeline Steel ◽  
Tensile Tests ◽  
X80 Pipeline Steel

scholarly journals FE Analysis of Critical Testing Parameters in Kolsky Bar Experiments for Elastomers at High Strain Rate

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3817
Author(s):  
Chaudhry ◽  
Czekanski
Keyword(s):  
Finite Element ◽  
High Strain Rate ◽  
Strain Rate ◽  
Pulse Shaping ◽  
High Strain ◽  
Kolsky Bar ◽  
Specimen Geometry ◽  
Strain Rates ◽  
Butadiene Rubber ◽  
Testing Apparatus

The main aim of this research is to present complete methodological guidelines for dynamic characterization of elastomers when subjected to strain rates of 100/s–10,000/s. We consider the following three aspects: (i) the design of high strain rate testing apparatus, (ii) finite element analysis for the optimization of the experimental setup, and (iii) experimental parameters and validation for the response of an elastomeric specimen. To test low impedance soft materials, design of a modified Kolsky bar is discussed. Based on this design, the testing apparatus was constructed, validated, and optimized numerically using finite element methods. Furthermore, investigations on traditional pulse shaping techniques and a new design for pulse shaper are described. The effect of specimen geometry on the homogeneous deformation has been thoroughly accounted for. Using the optimized specimen geometry and pulse shaping technique, nitrile butadiene rubber was tested at different strain rates, and the experimental findings were compared to numerical predictions.

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