FINITE ELEMENT ANALYSIS OF AN EARTH DAM SUBJECTED TO BLAST-INDUCED LOADING USING A HIGH STRAIN-RATE BOUNDING SURFACE MODEL

2015 ◽  
Author(s):  
Tianhua Xu ◽  
Limin Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Earth Dam ◽  
Surface Model ◽  
Bounding Surface ◽  
Element Analysis

A computational investigation on the influence of the l/d ratio and strain rate on the deformation behavior of rolled and homogeneous armor steel in the split Hopkinson pressure bar test process

2021 ◽  
pp. 095440892110365
Author(s):  
Ambuj Saxena ◽  
Shashi Prakash Dwivedi ◽  
Ashish K Srivastava ◽  
Shubham Sharma ◽  
Nitin Kotkunde
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Strain Rate ◽  
Strain Rate ◽  
Deformation Behavior ◽  
High Strain ◽  
Stress Strain ◽  
Element Analysis ◽  
Armor Steel ◽  
Strain Responses

The present investigation deals with the finite-element analysis of the high strain rate deformation behavior of the quenched and tempered armor-grade rolled and homogeneous armor steel. The rolled and homogeneous armor steel is extensively used in civil and military structures such as battle tanks, armament combat vehicles, combat helicopter, etc. The dynamic deformation behavior of rolled and homogeneous armor steel, that is, resistance against ballistic circumstances relates to its mechanical behavior under high strain rate conditions. In the present research work, a finite-element analysis investigation (using Abaqus finite-element analysis code) has been carried out to evaluate the influence of specimen l/d ratios and high loading strain rates on the deformation behavior and stress–strain responses of the rolled and homogeneous armor steel. Further, an attempt has also been made to check the high strain rate and specimen l/d ratio influence on the strain amplitudes of incident, reflected, and transmitted pulses. The numerical investigation has been carried out with the rolled and homogeneous armor steel specimen with l/d ratios of 1, 0.8, and 0.6. In addition, three high impact strain rates of 2130, 2907, and 3105 s−1 are considered to evaluate the stress–strain responses. The results revealed that the l/d ratio and strain rate have a significant influence on the specimen stress–strain response and the strain amplitudes of incident, reflected, and transmitted pulses. The peak stress value is increased with the increase in the l/d ratio and strain rate. The developed finite-element analysis model has predicted the stress–strain responses with <3% percentage error. The obtained finite-element analysis results have been validated with the experimental investigation with an l/d ratio of 0.6 and a strain rate of 3105 s−1 for rolled and homogeneous armor steel.

Research Progress on Finite Element Analysis Methods for Bonded Joints at Different Strain Rates

2014 ◽  
Vol 1049-1050 ◽  
pp. 892-900
Author(s):  
Zhe Min Jia ◽  
Guo Qing Yuan ◽  
David Hui
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Strain Rate ◽  
High Strain ◽  
Strain Rates ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Element Analysis ◽  
Adhesively Bonded Joints ◽  
Analysis Methods

Adhesive bonding is one of the effective ways to reduce the weight of structures. Researchers have done lots of numerical analysis and finite element analysis taking into account of the complex stress state in the bonded area, as well as the stress singularity occurs at the overlap edges with a view to efficiently predict the strength and rigidity of adhesively bonded joints. As they may suffer shock or impact loads in practice which leads to high strain rate in structures, analysis methods for adhesively bonded joints differ from that at quasi-static condition for two reasons: one is the mechanical properties of materials, including adhesives and substrates are different at high strain rates, the other is the additional consideration of elastic wave propagation in solid body. This article summaries several finite element analysis methods for adhesively bonded joints at high strain rate developed by domestic and foreign scholars and corresponding experimental standards for determining required parameters of each analytical method and raised some questions that need for further study.

Effect of temperature and punch speed on forming limit strains of AA5182 alloy in warm forming and improvement in failure prediction in finite element analysis

2017 ◽  
Vol 52 (4) ◽  
pp. 258-273 ◽  
Author(s):  
D Raja Satish ◽  
D Ravi Kumar ◽  
Marion Merklein
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Rate ◽  
Deep Drawing ◽  
Failure Prediction ◽  
Forming Limit ◽  
Element Analysis ◽  
Working Temperature ◽  
Warm Working ◽  
Punch Speed

Formability of AA5182-O aluminum alloy sheets in the warm working temperature range has been studied. Forming limit strains of sheets of two different thicknesses have been determined experimentally in different modes of deformation (biaxial tension, plane strain and tension–compression) by varying temperature and punch speed. A correlation has been established for plane strain intercept of the forming limit diagram (FLD0) with temperature, punch speed and thickness from the experimental results. This correlation has been used to plot the forming limit diagrams for failure prediction in the finite element analysis of warm deep drawing of cylindrical cups. The effect of strain and strain rate on material flow behavior has been incorporated using a strain rate–sensitive power hardening law in which the strain hardening exponent and strain rate sensitivity index have been experimentally determined. The predictions from simulations have been validated by warm deep drawing experiments. Large improvement in accuracy of failure prediction has been observed using the FLDs plotted based on the developed correlation when compared to the existing method of calculating FLD0 using only strain hardening coefficient and thickness. The results clearly indicate the importance of incorporating temperature and punch speed in failure prediction of Al alloys using FLDs in the warm working temperature range.

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%.

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