Numerical Simulation of Dynamic Tensile Extrusion Test of OFHC Copper

Abstract

The dynamic tensile extrusion (DTE) test offers unique possibility to probe material response under very large plastic strain, high strain rate and temperature to support constitutive modelling development. From the computational point of view, the DTE test is particularly challenging and a number of issues need to be assessed before proceeding with material modelling verification. In this work, an extensive and detailed computational work was carried out in order to provide the guidelines for accurate simulation of DTE test. Two constitutive models, the first phenomenological the latter physically-based, were used to simulated the behavior of fully annealed OFHC copper in dynamic extrusion at different velocities. Material models parameters were calibrated using uniaxial test data at different strain rates and temperatures. The number, size and shape of the ejected fragments at different velocity were used as validation metrics for the selected constitutive models. Results indicate that material behavior under dynamic extrusion can be accurately predicted limiting the influence of numerical parameters not related to the constitutive model under investigation. The physically based modelling allows a more accurate prediction of the material response and the possibility to incorporate microstructure evolution processes, such as dynamic recrystallization, which seems to control the response of OFHC copper in DTE tests at higher velocity.

Investigation on grain size effect in high strain rate ductility of 1100 pure aluminum

“…Preliminary numerical simulation using the MRK2 constitutive model were in good agreement with experimental results only for selected impact velocity probably due to the difference in the reference material flow curve at 0K that was derived from data reported in the literature. This result seems to confirm the use of DTE as robust test for material modelling validation as discussed in [5]. …”

“…Details on the derivation of these equations can be found elsewhere (Bonora, et al [5]). The parameters of the MRK2 model for AA1100-0 were calibrated using the experimental data given in Khan and Huang [6] and are reported in Table 1.…”

“…Ejected fragments were soft-recovered and the overall length of the jet was used as a measure of material elongation [4]. Preliminary numerical simulation of DTE test was performed in order to verify the predicting capabilities of the modified Rusinek-Klepaczko constitutive model [5].…”

Damage development in rod-on-rod impact test on 1100 pure aluminum

“…This model, which is physically based, assumes that the stress is the sum of the athermal, thermal and viscous drag terms. Details on the model formulation are given elsewhere (Bonora et al [11]). The BDM with pressure sensitivity of damage parameters was implemented in the code and used to predict the occurrence of damage development with varying impact velocity.…”

Celebrating 75 Years of the Society for Experimental Mechanics and the Study of Dynamic Behavior of Materials

“…The journal is highly international, publishing experimental and theoretical studies of metals [57], polymers [58], glasses [59], composites [60], granular materials [61], explosives [62], biological materials [63], geological materials [64], phase transitions [65], and structural response [66]. The journal includes application and development of techniques including split Hopkinson pressure bar/Kolsky bar [67], plate impact with light gas guns and powder guns [68], Taylor Anvil [69], Dynamic-TensileExtrusion [70], spectroscopy-and pyrometry-based shock temperature measurements [71], optical and X-ray imaging methods [72], interferometry and velocimetry techniques [73], dynamic fracture [74], laser based dynamic drivers [75], penetration and ballistics [76], equation of state [77], and spall failure [78].…”