Redesign of Die Internal Structure

Dr. Henry TanSchool of Mechanical, Aerospace and Civil Engineering

The University of Manchester

Finite Element Modeling

Commercial software: ANSYSABAQUS

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.

1st step:Geometry/Mesh Generation

3D Mesh Generation

Previous experience: 2D

3D Geometry description3D mesh generation

Same Mesh for Thermal/Structural Analysis

Same meshDifferent thermal/structural element

In sequentially coupled thermal/structural analysis:

Geometry description

2nd 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 load50C/hour, to 500C

Initial temperature distribution (at all nodes)900C

Need to define:

Boundary condition

Initialcondition

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, 10.5 W/Km @ 20 C 30 W/Km @ 1000 C

Structural Material Properties

Plasticity -> Nonlinear structural analysis

0.2% proof stress (as cast): 280 N/mm2@20C, 195 N/mm2@870C 110 N/mm2@900 C

80 N/mm2@1000 C, 45 N/mm2@1100 C

Ultimate Tensile Strength: 470 N/mm2@20C, 250 N/mm2@870C, 145 N/mm2@900C, 92 N/mm2@1000C, 53 N/mm2@1100C

Thermal expansion coefficient: 20-600C 17.8 x 10-6

20-800C 18.2 x 10-6

20-1000C 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