Benchmark Simulation Results: Channel Draw/Cylindrical Cup 2-Stage Test (Benchmark 3)

Transcription

1 Benchmark Simulation Results: Channel Draw/Cylindrical Cup 2-Stage Test (Benchmark 3) Thaweepat Buranathiti and Jian Cao * Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 628. * Corresponding author. Tel.: ; Fax: ; jcao@northwestern.edu INTRODUCTION In this third benchmark of NUMISHEET25, there is only one model participated. The following cover sheet (Table C-1) is reproduced and numbered BM3.8. The cover sheets provide participant information, computer code name, basic model information, and computation time. The readers are encouraged to review the cover sheet together with the figures to study the benchmark. Parameters of interest in this benchmark study are the punch load curve during stage 1 forming, sidewall curl radius after stage 1, major and minor true strains after stage 1, residual stresses through the sheet thickness after stage 1 unloading, the punch load curve during stage 2 forming, and true stresses and strains after stage 2 at particular locations. The participating submission is compared to experimental data corresponding to each material (AKDQ, DP6, HSLA5, and AL622-T4). It is noted that there is no analysis report of this benchmark problem. Fig. C1 Fig. C2 Fig. C3 Fig. C4 Fig. C5 Figs. C6-C7 Figs. C8-C9 Figs. C1-C13 Figs. C14-C15 Figs. C16-C19 Punch loading curves during stage 1 forming for AKDQ and DP6. Punch loading curves during stage 1 forming for HSLA5 and AL622-T4. Sidewall curl radius (mm) after stage 1 forming. Major true strain at P3 after stage 1 forming. Minor true strain at P3 after stage 1 forming. Residual stress (MPa) through sheet thickness after stage 1 forming. Punch loading curve during stage 2 forming for specimen A True stresses and net true strains along X and Y at P4 after stage 2 forming for specimen A Punch loading curve during stage 2 forming for specimen B True stresses and net true strains along X and Y at P4 after stage 2 forming for specimen B 1121

2 Table C-1: NUMISHEET 25 Benchmark 3: BM3.8 Channel Draw/Cylindrical Cup 2-Stage Test Benchmark participant: Affiliation: Address: Phone number: Fax number: Name of the FEM code: General aspects of the code: Basic formulations: Element/Mesh technology: Number of elements: Type of elements: CPU type: CPU clock speed: Number of CPU 1 Main memory: Operating system: CPU-Time: L. F. Menezes, J.L. Alves, A.J. Baptista and M.C. Oliveira Departament of Mechanical Engineering, FCTUC, University of Coimbra Polo II, Pinhal de Marrocos, Coimbra, Portugal luis.menezes@dem.uc.pt, jlalves@dem.uminho.pt, antonio.baptista@dem.uc.pt, marta.oliveira@dem.uc.pt DD3IMP Fully implicit (single iterative loop to treat non-linear elastoplasticity and contact with friction) Elasto-plastic formulation with isotropic and kinematic hardening, several yield criteria and an augmented Lagrangian approach to treat contact with friction (Coulomb's law); tools modelled by Bézier surfaces Phase 1: 192 FE, 322 nodes; Phase 2: About 87 FE, 12 nodes Isoparametric 3D brick elements with selective reduced integration technique Intel Pentium GHz 2. GB RDRAM Windows XP Phase 1: About 1 hours; Phase 2: About 78 hours Which type of draw bead is used in your draw simulation, line bead (1) or physical bead (2)? Enter 1 or 2 in Column B: 2 Describe the material model that is used for each metal (Include model parameters if different from the Standard Material File) Yield Function/Plastic Potential AKDQ 3 DP 6 3 HSLA 5 3 AL 622-T4 3 Hardening Law (Isotropic/or form of Kinematic) AKDQ 1 DP 6 1 HSLA 5 1 AL 622-T4 1 Stress-Strain Relation AKDQ 2 DP 6 2 HSLA 5 2 AL 622-T

3 Remarks: Due to material and part symmetry in Phase 1 only one quarter of the total part was simulated. For similar reasons, in Phase 2 only one half of the total part was simulated. The washer was not considered in the simulation of Phase 2. Instead the tool geometry was corrected according with the washer thickness. The friction coefficient considered for Phase 2 is the value recommend for each material. The sheet is discretized with 3 FE layers throughout thickness in both phases. Since the sidewall curl is not constant the value reported was evaluated for Point 3. Phase 1 delivered strain values correspond to eigenvalues 1 and 2. Stress values are in the global X and Y directions (X-In plane TD, Y -In plane RD). Phase 2 delevered strain and stress values are in the global X and Y directions (X-In plane TD, Y -In plane RD). Strain values corresponds to the accumulated (Phase 1+Phase 2) values. 1123

4 Stage Punch load (kn) (AKDQ) (DP6) BM3.8 (AKDQ) BM3.8 (DP6) Punch displacement (mm) Figure C-1: Punch loading curves during stage 1 forming for AKDQ and DP6. Stage Punch load (kn) (HSLA5) (AL622-T4) BM3.8 (HSLA5) BM3.8 (AL622-T4) Punch displacement (mm) Figure C-2: Punch loading curves during stage 1 forming for HSLA5 and AL622-T

5 After Stage 1 BM Sidewall Curl Radius (mm) AKDQ DP6 HSLA5 AL622-T4 Figure C-3: Sidewall curl radius (mm) after stage 1 forming After Stage 1 BM3.8 Major true strain at P AKDQ DP6 HSLA5 AL622-T4 Figure C-4: Major true strain at P3 after stage 1 forming. 1125

6 After Stage 1 BM Minor true strain at P AKDQ DP6 HSLA5 AL622-T4 Figure C-5: Minor true strain at P3 after stage 1 forming. X-dir. (AKDQ) X-dir. (DP6) Y-dir. (AKDQ) Y-dir. (DP6) Position along sheet thickness (mm) Residual stress (MPa) Figure C-6: Residual stress (MPa) through sheet thickness after stage 1 forming. 1126

7 X-dir. (HSLA5) X-dir. (AL622-T4) Y-dir. (HSLA5) Y-dir. (AL622-T4) Position along sheet thickness (mm) Residual stress (MPa) Figure C-7: Residual stress (MPa) through sheet thickness after stage 1 forming. Stage 2, Specimen A (AKDQ) (DP6) BM3.8 (AKDQ) BM3.8 (DP6) Punch load (kn) Punch displacement (mm) Figure C-8: Punch loading curve during stage 2 forming for specimen A for AKDQ and DP

8 Stage 2, Specimen A 6 5 (HSLA5) (AL622-T4) BM3.8 (HSLA5) BM3.8 (AL622-T4) Punch load (kn) Punch displacement (mm) Figure C-9: Punch loading curve during stage 2 forming for specimen A for HSLA5 and AL622-T4. Specimen A, Stage2 BM3.8 9 True stress along X at P4 (MPa) AKDQ DP6 HSLA5 AL622-T4 Figure C-1: True stress along X at P4 after stage 2 forming for specimen A. 1128

9 Specimen A, Stage2 16 BM3.8 True stress along Y at P4 (MPa) AKDQ DP6 HSLA5 AL622-T4 Figure C-11: True stress along Y at P4 after stage 2 forming for specimen A. Specimen A, Stage2.1 BM3.8 Net true strain along X at P AKDQ DP6 HSLA5 AL622-T4 Figure C-12: Net true strain along X at P4 after stage 2 forming for specimen A. 1129

10 Specimen A, Stage2.3 BM3.8 Net true strain along Y at P AKDQ DP6 HSLA5 AL622-T4 Figure C-13: Net true strain along Y at P4 after stage 2 forming for specimen A. Stage 2, Specimen B 12 1 (AKDQ) (DP6) BM3.8 (AKDQ) BM3.8 (DP6) Punch load (kn) Punch displacement (mm) Figure C-14: Punch loading curve during stage 2 forming for specimen B for AKDQ and DP6. 113

11 Stage 2, Specimen B (HSLA5) (AL622-T4) BM3.8 (HSLA5) BM3.8 (AL622-T4) Punch load (kn) Punch displacement (mm) Figure C-15: Punch loading curve during stage 2 forming for specimen B for HSLA5 and AL622-T4. Specimen B, Stage2 BM True stress along X at P4 (MPa) AKDQ DP6 HSLA5 AL622-T4 Figure C-16: True stress along X at P4 after stage 2 forming for specimen B. 1131

12 Specimen B, Stage2 9 BM3.8 True stress along Y at P4 (MPa) AKDQ DP6 HSLA5 AL622-T4 Figure C-17: True stress along Y at P4 after stage 2 forming for specimen B. Specimen B, Stage2.3 BM3.8 Net true strain along X at P AKDQ DP6 HSLA5 AL622-T4 Figure C-18: Net true strain along X at P4 after stage 2 forming for specimen B. 1132

13 Specimen B, Stage2 -.1 BM3.8 Net true strain along Y at P AKDQ DP6 HSLA5 AL622-T4 Figure C-19: Net true strain along Y at P4 after stage 2 forming for specimen B. 1133