Computational Material Models for TSCP Plastics Comparison of the Deformation Behavior with MAT 24 and MAT SAMP-1 with DIEM
The subject of this article is comparison of the deformation and stress response for two computational material models suitable for POM material. Both material models use erosion of finite elements, but in the first case *MAT_24 is used together with MAT_ADD_EROSION and with parameters combination and in the second case *MAT_SAMP-1 is used together with DIEM (Damage Initiation and Evolution Model). The new computation material model SAMP-1 was built based on the original experimental data used for *MAT_24 and additional tests (3-point bending test, puncture test, etc.). The strain rate effect is considered based on the experiments in defined range and other strain rate values were calculated based on the analogue with Johnson-Cook constitutive material model. The attention is focused on tensile/pressure definition of computational material model in plasticity. This is very important effect for good prediction of the cracks with using damage material model DIEM. The next characteristic is an accumulation of the damage which leads to rupture and finite elements deletion. This property is depending on the stress triaxiality. The results of deformation and stress response are very different for both approaches and SAMP-1 gives closer results to the experimental reality. The two types of the practical tasks are used for comparison of the stress and deformation behavior of these two computational material models. The first comparison checks deformation and stress response and second case tests difference between damage models. This work directly connects to previous articles for FSM (Fuel Supply Modules) introduced in preceding LS-DYNA conferences. We find some non-physical behavior of the *MAT_SAMP-1 for specific configuration. So, this article is appeal for LS-DYNA users and developers to propose of solving of this non-physical behavior *MAT_SAMP-1 in specific situation, like as contact, compression loading area.
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Computational Material Models for TSCP Plastics Comparison of the Deformation Behavior with MAT 24 and MAT SAMP-1 with DIEM
The subject of this article is comparison of the deformation and stress response for two computational material models suitable for POM material. Both material models use erosion of finite elements, but in the first case *MAT_24 is used together with MAT_ADD_EROSION and with parameters combination and in the second case *MAT_SAMP-1 is used together with DIEM (Damage Initiation and Evolution Model). The new computation material model SAMP-1 was built based on the original experimental data used for *MAT_24 and additional tests (3-point bending test, puncture test, etc.). The strain rate effect is considered based on the experiments in defined range and other strain rate values were calculated based on the analogue with Johnson-Cook constitutive material model. The attention is focused on tensile/pressure definition of computational material model in plasticity. This is very important effect for good prediction of the cracks with using damage material model DIEM. The next characteristic is an accumulation of the damage which leads to rupture and finite elements deletion. This property is depending on the stress triaxiality. The results of deformation and stress response are very different for both approaches and SAMP-1 gives closer results to the experimental reality. The two types of the practical tasks are used for comparison of the stress and deformation behavior of these two computational material models. The first comparison checks deformation and stress response and second case tests difference between damage models. This work directly connects to previous articles for FSM (Fuel Supply Modules) introduced in preceding LS-DYNA conferences. We find some non-physical behavior of the *MAT_SAMP-1 for specific configuration. So, this article is appeal for LS-DYNA users and developers to propose of solving of this non-physical behavior *MAT_SAMP-1 in specific situation, like as contact, compression loading area.
01_Dobes_Navratil_Robert_Bosch.pdf
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