Thermal-mechanical Metal-forming Simulations in LSDYNA (revisited)

1. Thermal-mechanical Metal-forming Simulations in LSDYNA (revisited) Rudolf BötticherTMB GmbH www.rudolf-boetticher.de 

2. Motivation • Assess adaptive (space, time) coupled simulations (SOLN=2) with plastic heating for nodal pressure tetraheadrons (ELFORM=13) and EFG elements. • 1. Methods and Keywords • 2. Adaptive 3D (EFG) Tets • 3. Adaptive axi-2D • 4. Conclusions www.rudolf-boetticher.de

3. Caution: SMP vs. Serial! Using Real DMF solver and MMD ordering stiffness matrix data -------------------------------------------------------------- number of equations = 4957 stiffness coefficients = 0.1 Mw expanding memory to 1671039 imfisgy sym. storage 1 expanding memory to 1675184 imfisgy sym. storage 3 Memory Requirements: incore out-of-core TOTAL for linear algebra = 1.7 0.5 Mw TOTAL for entire job = 3.3 2.1 Mw TOTAL available = 20.0 20.0 Mw expanding memory to 19802133 imfisgy numeric storage ic an INCORE solution will be performed Symbolic Factorization CPU = 0.000E+00 seconds Numeric Factorization CPU = 1.000E+00 seconds Using Real DMF solver and MMD ordering stiffness matrix data -------------------------------------------------------------- number of equations = 3640 stiffness coefficients = 0.0 Mw expanding memory to 1572951 imfisgy sym. storage 1 expanding memory to 1591753 imfisgy sym. storage 2 expanding memory to 1602395 imfisgy sym. storage 3 Memory Requirements: incore out-of-core TOTAL for linear algebra = 0.9 0.3 Mw TOTAL for entire job = 2.4 1.8 Mw TOTAL available = 20.0 20.0 Mw expanding memory to 19897094 imfisgy numeric storage ic an INCORE solution will be performed Symbolic Factorization CPU = 0.000E+00 seconds ******************************************************** * - WARNING - * * 544 negative eigenvalues detected during * * factorization of linear equation system. * ******************************************************** Implicit needs no mass scaling. Thermal always implicit! www.rudolf-boetticher.de

4. Keywords • *CONTROL_ADAPTIVE • *CONTROL_REMESHING • *SECTION_SOLID_EFG 1,41 1.4,1.4,1.4,,,4,3 • *CONTROL_IMPLICIT_GENERAL/AUTO • *CONTROL_THERMAL_SOLVER/TIMESTEP www.rudolf-boetticher.de

5. Single frames printed as *.jpg and mounted with Gifmerge. Scripting critical. 3D Remarks: LSPP Windows: saving of juxtaposed animation impossible. EFG has a mesh. Not adaptive alone. Adaption may fail at complicated surfaces. Results of explicit, implicit, adaptive and explicit EFG are sound. www.rudolf-boetticher.de

6. 2D-axi Remarks: Better concept for displaying plastic strain at a given point for adaptive needed for LSPP Adaptive EFG works in explicit. Severe constraints on time step for mass scaling. Plastic strain is projected correctly during adaption. Element and node numbers are reused! EFG www.rudolf-boetticher.de

7. 2D-axi Remarks: 971.7600 projects plastic heating during adaption faulty. www.rudolf-boetticher.de

8. Concluding Remarks • Lacking a more intuitive definition of SPC boundary conditions and forcing functions that are robust unter switching between implicit, explicit and adaptive. • Advantages of EFG often limited. • Projections of plastic heating for axi-2D false. • LSPP on Windows has still room for improvements. www.rudolf-boetticher.de