ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # WS5B-1 Workshop 5B Localized Yielding Workbench-Mechanical Structural Nonlinearities

Workbench Mechanical – Structural Nonlinearities WS5B-2 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Goal Introduce Metal Plasticity to the Workshop 4A problem and compare its effect on results (contact pressure and preload) Model Description 2D Axisymmetric model of injection molding machine nozzle tip assembly Materials: – Tool Steel for Housing (760Mpa Yield Strength) – Copper alloy for Tip (280Mpa Yield Strength) – Titanium for Insulator Workshop 5B: Localized Yielding Housing Tip Insulator

Workbench Mechanical – Structural Nonlinearities WS5B-3 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Model Description (cont’d) Contact Pairs: A.Frictionless contact at Housing to Nozzle tip face seal B.Bonded contact at Nozzle tip To insulator C.Bonded contact at threaded connection between Housing and Nozzle tip (thread details not modeled) Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-4 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Model Description (cont’d) Thermal Boundaries: A.Hot 220C B.Cold manifold C.Nozzle tip band 80 Watts … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-5 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Model Description (cont’d) Structural Boundaries A.Frictionless Nozzle Housing Flange B.Frictionless Insulator Structural Loads –1 st loadstep reconciles interference fit between housing and tip face seal – 2 nd loadstep reads in temperatures from steady state thermal run – 3 rd loadstep applies pressure to melt channel wall. melt channel wall … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-6 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Steps to Follow: If you already have Workbench open from a previous run, start a new analysis with Utility Menu>File>New… Browse for and open “W5B-Offset.wbpj” project file. … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-7 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement The Project Schematic should look like the picture below. … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-8 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Highlight the Engineering Data Cell and double click to open – Verify the predefined material properties – Verify that the units are in Metric (Tonne,mm,…) system. – If not, fix this by clicking on… Utility Menu>Units>Metric(Tonne, mm,..) … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-9 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Highlight the Copper NL and Stainless Steel NL materials to confirm that the plasticity models have been defined with Bilinear Isotropic laws as show below. … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-10 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Return to the project schematic page Double click (or RMB=>Edit…) on the Thermal Model Cell to open Mechanical Session … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-11 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Highlight the Housing and Nozzle Tip components – In the Details Window, turn Nonlinear Effects ON to include the plasticity effects … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-12 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Execute a SOLVE – The convergence now takes over 20 iterations, up from just 9 (WS4A) when all materials were considered linear elastic. … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-13 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Post process the contact pressure – Notice the dramatic difference in pressure distribution at the seal face as well as the peak value when compared with same results published in workshop 4A … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-14 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Post process the preload at the frictionless contact resulting from the interference fit as before. Compare the preload with workshop 4A. – Note, the change in preload is not nearly as dramatic as that of the contact pressure. Why? … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-15 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Highlight the Solution Branch – RMB>Insert>Strain>Equivalent Plastic Strain – Note: Yielding is concentrated locally at the melt channel wall. Material remains elastic across most of the seal face. Hence, preload does not change very much. … Workshop 5B: Localized Yielding

Workbench Mechanical – Structural Nonlinearities WS5B-16 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. April 30, 2009 Inventory # Workshop Supplement Post process equivalent stress and compare to results published at end of workshop 4A. … Workshop 5B: Localized Yielding