Finite element simulation of thick steel plate stamping
Sippola, Pekka (2011)
Sippola, Pekka
2011
Konetekniikan koulutusohjelma
Automaatio-, kone- ja materiaalitekniikan tiedekunta - Faculty of Automation, Mechanical and Materials Engineering
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Hyväksymispäivämäärä
2011-12-07
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-2011121514940
https://urn.fi/URN:NBN:fi:tty-2011121514940
Tiivistelmä
Finite element simulation is a convenient tool for optimising a stamping process. By using it in the design process, the quality of the product can be improved without the expense of constructing a physical model for experimental testing. This thesis was made for the purpose of studying the theory of finite element stamping simulation so that it could be implemented to study a simulation of a specific stamping process performed on a 30 millimeter thick steel plate. The thesis is focused on the numerical finite element simulation of stamping, not on the practical applications of performing these forming processes.
The literature study part of this thesis is mainly focused on the sources of nonlinearity and the solution methods for integrating the nonlinear dynamic equations. The nonlinearity is caused by metal plasticity, large displacements/strains and changing contact conditions. The practical simulation part is performed with Abaqus finite element analysis software suite using both Abaqus/Standard and Abaqus/Explicit codes. A simplified two-dimensional (2D) plane strain model is compared to a more costly, but more thorough, three-dimensional (3D) model. The explicit and implicit solution methods are compared with the different models. Also, a parametrical study on the material properties is performed with the 2D model.
It was found that the studied stamping process is unlikely to succeed in practice without major improvements on the geometry design of the tooling. The 2D model misses important details when compared to the 3D model although offering signifi- cant reduction in computational time. Therefore, it is recommended for use only in the initial design process for optimisation purposes. The 3D model is recommended for use in an almost complete design process to verify the results and to further improve the design. Complicated contact conditions caused the simulations with the shell element model to break down so that the simulation had to be performed with a solid continuum element model. The advantages of the explicit solution in the 3D model and the advantages of the implicit solution in the 2D model were recognized. The implicit dynamic solution offers advantages over the static implicit procedure by improved convergence of the iterations when hard contact is modelled. The choice of material model is also an important aspect in the simulation. /Kir11
The literature study part of this thesis is mainly focused on the sources of nonlinearity and the solution methods for integrating the nonlinear dynamic equations. The nonlinearity is caused by metal plasticity, large displacements/strains and changing contact conditions. The practical simulation part is performed with Abaqus finite element analysis software suite using both Abaqus/Standard and Abaqus/Explicit codes. A simplified two-dimensional (2D) plane strain model is compared to a more costly, but more thorough, three-dimensional (3D) model. The explicit and implicit solution methods are compared with the different models. Also, a parametrical study on the material properties is performed with the 2D model.
It was found that the studied stamping process is unlikely to succeed in practice without major improvements on the geometry design of the tooling. The 2D model misses important details when compared to the 3D model although offering signifi- cant reduction in computational time. Therefore, it is recommended for use only in the initial design process for optimisation purposes. The 3D model is recommended for use in an almost complete design process to verify the results and to further improve the design. Complicated contact conditions caused the simulations with the shell element model to break down so that the simulation had to be performed with a solid continuum element model. The advantages of the explicit solution in the 3D model and the advantages of the implicit solution in the 2D model were recognized. The implicit dynamic solution offers advantages over the static implicit procedure by improved convergence of the iterations when hard contact is modelled. The choice of material model is also an important aspect in the simulation. /Kir11