Redesign of Die Internal Structure Dr. Henry Tan School of Mechanical, Aerospace and Civil Engineering The University of Manchester
Finite Element Modeling Commercial software: ANSYS ABAQUS Thermal, structural analysis Mathematical details skipped
Model Cooling Process Sequentially coupled thermal/structural analysis: Input of structural analysis depends on the results from thermal analysis.
1 st step: Geometry/Mesh Generation
3D Mesh Generation Previous experience: 2D 3D Geometry description 3D mesh generation
Same Mesh for Thermal/Structural Analysis Same mesh Different thermal/structural element In sequentially coupled thermal/structural analysis: Geometry description
2 nd step: Coupled Fields Analysis
Basics for Thermal Analysis Solve the heat balance equation Finite element solution gives: Nodal temperature
Transient Thermal Analysis Time dependent cooling load 50C/hour, to 500C Initial temperature distribution (at all nodes) 900C Need to define: Boundary condition Initial condition
Thermal Stress Analysis Input: nodal temperatures that a transient thermal analysis calculates Output: thermal stresses Solve the force balance equation
Thermal Material Properties Temperature dependence -> Nonlinear thermal analysis Thermal conductivity, C C
Structural Material Properties Plasticity -> Nonlinear structural analysis 0.2% proof stress (as cast): 280 N/mm C, 195 N/mm C 110 N/mm C 80 N/mm C, 45 N/mm C Ultimate Tensile Strength: 470 N/mm C, 250 N/mm C, 145 N/mm C, 92 N/mm C, 53 N/mm C Thermal expansion coefficient:20-600C 17.8 x C 18.2 x C 18.9 x 10 -6
Results from Finite Element Modeling Temperature-time curves for selected locations (corners) Stress-time curves for selected locations (corners) distortion-time curves for selected locations (corners) Temperature field (picture) at selected cooling time Stress field at selected cooling time Deformation field at selected cooling time Animation for temperature evolution on the die surface Animation for stress evolution on the die surface Animation for deformation evolution on the die surface