Numerical Simulation of Waveform Adjustment in high G Accelerometer Calibration System Using Hopkinson Bar

Linearity, dynamic linearity particularly, is an important parameter in measuring the performance of an accelerometer. The Hopkinson bar has been widely used in calibration of high g accelerometer and other high overloading conditions. Based on one-dimension stress wave theory and superposition theory of elastic waves, designed a Dual Warhead Hopkinson bar to demarcate the dynamic linear parameters of high g micro accelerometer accurately. A finite element model for Hopkinson bar calibration system was created, ANSYS/LS-DYNA was employed to simulate the operation process of Hopkinson bar, and the effects of the projectile's materials, adjustment pads materials and thickness on the acceleration waveform were found.

Download Full-text

Numerical simulation of dynamic TPB fracture test in a modified Hopkinson bar

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:20020711 ◽

2003 ◽

Vol 110 ◽

pp. 305-310 ◽

Cited By ~ 2

Author(s):

J. Loya ◽

J. Fernandez-Saez ◽

C. Navarro

Keyword(s):

Numerical Simulation ◽

Hopkinson Bar ◽

Fracture Test ◽

Modified Hopkinson Bar

Download Full-text

The Influence of Material Constitutive Constants on Numerical Simulation of Orthogonal Cutting of Titanium Alloy Ti6Al4V

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.375-376.182 ◽

2008 ◽

Vol 375-376 ◽

pp. 182-186 ◽

Cited By ~ 2

Author(s):

Jian Ling Chen ◽

Jian Feng Li ◽

Jie Sun ◽

Zhong Qiu Wang ◽

Zhi Ping Xu

Keyword(s):

Numerical Simulation ◽

Titanium Alloy ◽

Orthogonal Cutting ◽

Chip Morphology ◽

Hopkinson Bar ◽

Material Constants ◽

Metal Machining ◽

Split Hopkinson ◽

Titanium Alloy Ti6al4v ◽

2D Numerical Model

Johnson-Cook (JC) constitutive model is extensively used in the simulation of metal machining. There are several different sets of JC material constants for titanium alloy Ti6Al4V fitted by split-Hopkinson bar (SHPB) tests. However, few researches have been done to study their sensitivity on the behavior of cutting. In this work, four different sets of material constants were performed in a 2D numerical model to simulate the cutting process of titanium alloy Ti6Al4V. The effects of the four sets of material constants on the predicted cutting forces, chip morphology and temperature were studied. It is shown that all the considered process outputs are very sensitive to material constitutive constants. Some quantitive comparisons with experimental results reported in the literature were also made.

Download Full-text

Numerical simulation and experimental study of a mechanism for Hopkinson bar test interruption

The Journal of Strain Analysis for Engineering Design ◽

10.1243/03093247jsa206 ◽

2007 ◽

Vol 42 (3) ◽

pp. 163-172 ◽

Cited By ~ 7

Author(s):

Y El-Saeid Essa ◽

J López-Puente ◽

J. L Pérez-Castellanos

Keyword(s):

Numerical Simulation ◽

Experimental Study ◽

Hopkinson Bar ◽

Bar Test

Download Full-text

Dynamic Modeling and Calibration of the Acceleration Sensor Based on System Identification Theory

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.740.527 ◽

2015 ◽

Vol 740 ◽

pp. 527-530

Author(s):

Fu Jing Xu ◽

Tie Hua Ma

Keyword(s):

System Identification ◽

Response Speed ◽

Hopkinson Bar ◽

Dynamic Measurement ◽

Test System ◽

Calibration System ◽

Acceleration Sensors ◽

Measurement Results ◽

Dynamic Errors ◽

Identification Theory

In the process of acceleration dynamic measurement, the measurement results have quite large dynamic errors, due to the resonance of acceleration sensors. Using the system identification theory and combining with the dynamic calibration experimental data of acceleration calibration system based on Hopkinson bar, the dynamic model of the sensor is deduced, the dynamic compensation filter is designed. Simulation results show that the compensation filter can broaden the work band effectively. It improves the system dynamic response speed by nine times and advances the measuring accuracy of the test system.

Download Full-text

Numerical Simulation on the specimen dynamic plastic deformation behaviour in the torsional split Hopkinson bar test

EPJ Web of Conferences ◽

10.1051/epjconf/201818301020 ◽

2018 ◽

Vol 183 ◽

pp. 01020

Author(s):

Chen Gang ◽

Huang Xicheng ◽

Chen Junhong ◽

Zhong Weizhou

Keyword(s):

Numerical Simulation ◽

High Strain ◽

Hopkinson Bar ◽

Experimental Results ◽

Shear Behaviour ◽

Strain Rates ◽

Dynamic Shear ◽

Split Hopkinson ◽

Strain Stress ◽

Strain Signal

The torsional split Hopkinson bar (SHB) is an important method to study the dynamic shear behaviour and shear localization of materials under high strain rates. Different specimen sizes were used in literatures, and the size of the specimen might have an effect on the experimental results. Numerical simulation on torsional SHB tests was carried out with LS-DYNA. The strain signal on the incident and transmitted bars were obtained from the simulation just as the experiment. Then the numerical strain-stress relationship of the material was derived from the numerical strain signal using the experiments data process of torsional SHB. The agreement between numerically derived strain-stress results and the specimen material properties specified in numerical modelling indicates that the torsional SHB is applicable to study the dynamic shear behaviour of materials under high strain rates. The specimen gauge diameter has no significant effect on the dynamic torsional test result. However, higher adhesive strength is required to fix the larger gauge diameter specimen on the bars. The specimen gauge thickness has little effect on the experimental results with a modified formula to calculate the specimen stress. Still, the increase of specimen gauge thickness will lead to the increase of non-uniformity of specimen stress and strain (strain rate). Based on the simulation analysis, suggestions on the specimen size design are given as well.

Download Full-text