A coupled experimental/numerical approach for the characterization of material behaviour at high strain-rate using electromagnetic tube expansion testing

Jeanson, Anne-Claire; Bay, François; Jacques, Nicolas; Avrillaud, G.; Арригони, М.; Mazars, Gilles

doi:10.1016/j.ijimpeng.2016.07.002

Cited by 14 publications

(8 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…cycle. This is similar to the direct measurement of velocity using PDV technique is A1060 alloy [22]. The simulation of displacement predicts a diametral expansion of ~17 mm.…”

Section: Em Expansion Of Aa5052 Tubessupporting

confidence: 71%

“…The maximum displacement rates are greater than 100 m/s. There is significant difference in the rates of the two peaks which is in variance with the observation by Jeanson et al [22]. These differences could arise because of the simplifications used for simulations such as the use of 2D axi-symmetric model of tube, considering circular coils rather than helical and ignoring temperature dependency of the material.…”

Section: Em Expansion Of Aa5052 Tubesmentioning

confidence: 65%

“…This indicates that by increasing the current level the generated peak magnetic force in increased in magnitude in the initial few pulses. As a result, the ability of the gen- large strains under adiabatic conditions [22] which make the later more suitable for study of fragmentation. However the stresses are not uniaxial primarily because of axial inertial stress components creating a plane stress situation.…”

Section: Evolution Of Tangential Stresses In Expanding Tubementioning

confidence: 99%

See 2 more Smart Citations

Electromagnetic Expansion and Fragmentation of Hollow Aluminium 5052 Tube

Choudhary¹,

Gupta²,

Tiwari³

et al. 2020

JMMCE

View full text Add to dashboard Cite

Electromagnetic forming is a high-speed forming technology by which hollow profiles can be compressed or expanded. It is done with a pulsed magnetic field to apply Lorentz' forces at electrically conductive material. Electromagnetic hollow tube expansion is limited by the fragmentation tendency. This work attempts to use a combination of analytical and computational approach to compute the net tangential stress during tube expansion. A simplified analytical framework to estimate the temporal evolution of plastic stresses present in aluminium alloy AA5052 at low and high applied magnetic pressures is developed based upon dynamic imaging. The time resolved images captured using current synchronised high speed camera record the overall dimensional changes of the tube that is validated by multi-physics simulation of expansion process. Imaging of hollow tube expansions at two selected peak currents has been carried out at various current levels in the range 76-160 kA. The direct visualisation of the increase in the tube diameter at two current levels provided a comparison of the developing net tangential stresses in the hollow tube during the undamaged and fragmented expansion. Imaging of tube expansion also facilitates the estimation of the strain rate experienced by the tube and was in the range of ~1700 s −1 to ~1200 s −1. The propensity of fragmentation was found to be due to the level and duration of generated tangential stresses above the yield stress during expansion of the aluminium tubes. Presented study provides a mean of exploiting the enhanced formability of aluminium alloys using electromagnetic forming.

show abstract

“…cycle. This is similar to the direct measurement of velocity using PDV technique is A1060 alloy [22]. The simulation of displacement predicts a diametral expansion of ~17 mm.…”

Section: Em Expansion Of Aa5052 Tubessupporting

confidence: 71%

Section: Em Expansion Of Aa5052 Tubesmentioning

confidence: 65%

Section: Evolution Of Tangential Stresses In Expanding Tubementioning

confidence: 99%

See 1 more Smart Citation

Electromagnetic Expansion and Fragmentation of Hollow Aluminium 5052 Tube

Choudhary¹,

Gupta²,

Tiwari³

et al. 2020

JMMCE

View full text Add to dashboard Cite

show abstract

“…The popularity of computer simulations to study fragmentation problems is partly due to the elevated cost of fragmentation experiments, and the fact that there are only a few laboratories in the world with the equipment and skills required to perform such tests (e.g. high-velocity expansion of ring [28,9,2,47,15,3], thin-walled cylinders [35,14,7,48,16] and hemispherical shells [19]). In addition, the finite element calculations have the potential to provide information about the mechanisms which control multiple necking and fragmentation that is not accessible by experimentation.…”

Section: Introductionmentioning

confidence: 99%

“…Fig. A 16. shows the number of necks n as a function of the number of imperfections N for an imposed initial strain rate ofε 0 = 16667 s −1 (which corresponds to V r = 250 m/s).…”

mentioning

confidence: 99%

Multiple necking patterns in elasto-plastic rings subjected to rapid radial expansion: The effect of random distributions of geometric imperfections

Marvi-Mashhadi¹,

Rodríguez-Martínez²

2020

International Journal of Impact Engineering

View full text Add to dashboard Cite

In this paper we have investigated, using finite element calculations performed in ABAQUS/Explicit [1], the effect of ab initio geometric imperfections in the development of multiple necking patterns in ductile rings subjected to dynamic expansion. Specifically, we have extended the work of , who studied the formation of necks in rings with sinusoidal spatial perturbations of predefined amplitude and constant wavelength, by considering specimens with random distributions of perturbations of varying amplitude and wavelength. The idea, which is based on the work of El Maï et al. [4], is to provide an idealized modeling of the surface defects and initial roughness of the rings and explore their effect on the collective behavior and spacing of the necks. The material behavior has been modeled with von Mises plasticity and constant yield stress, and the finite element simulations have been performed for expanding velocities ranging from 10 m/s to 1000 m/s, as in ref. [33]. For each speed, we have performed calculations varying the number of imperfections in the ring from 5 to 150. In order to obtain statistically significant results, for each number of imperfections, the computations have been run with five random distributions of imperfection wavelengths.For a small number of imperfections, the variability in the wavelengths distribution is large, which makes the imperfections play a major role in the necking pattern, largely controlling the spacing and growth rate of the necks. As the number of imperfections increases, the variability in the wavelengths distribution decreases, giving rise to an array of more regularly spaced necks which grow at more similar speed. A key outcome is to show that, for a large number of imperfections, the number of necks formed in the ring comes closer to the number of necks obtained in the absence of ab initio geometric imperfections.

show abstract