ANSYS 14 Structural Mechanics Composites

© 2011 ANSYS, Inc. November 22, 2011

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Composites modeling with ANSYS

Modeling Layered Composites the Simple Way


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Composites offer tremendous weight savings, increased performance, and design flexibility

The composites market is a relatively young, fast growing and technologically evolving market

Motivation


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Multiple materials, complex layups, large number of plies etc. makes the job difficult to design parts with these materials

Compared to homogenous materials like steel or plastic, composites are much more challenging to analyze

Challenges


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“The intuitive implementation of composite design development in ANSYS Composite PrepPost brought out a revolution in composite simulations. We are able to realize a continuous design process from simulation results to manufacturing including design modifications within the development.“

Hendrik Mester, Rotor Blade Development, REpower Systems AG


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Shell based composites


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Motivation

Analyzing Composites in R14.0

ANSYS Workbench provides superior CAD connectivity, meshing and a easy framework to perform design optimization

With R14.0, we greatly improve the workflow for analysis of composite components


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New at Release 14.0

Orthotropic stress/strain strength properties

Tsai-Wu, Puck, LaRc03/04 Constants

Properties available to ACP and Mechanical and MAPDL

Engineering Data Enhancements New in R14


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Manually Defining Layers on Simple Geometries

Users can define simple layered sections for a shell body as well as define thicknesses and angles as parameters


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Layered Section Object

Allows a user to define simple layered section for a shell body

Inserted under the Geometry folder from the toolbar or its RMB insert menu

Basic Layer Definition in Mechanical New in R14


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Details

Layered Section Object

Worksheet View to enter layer data

Thickness, angle values can be parameterized

Options to define offset and sequencing

Scope to bodies or faces

Graphics option to display specific layer to help verify correct offset, sequence, etc.


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Graphics : Section Thickness , Location

Layered Section Object Example


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Layer Control, Membrane/Bending Output

Postprocessing

Ability to choose which layer to view results

New Membrane-Bending stress results.


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Explicit Composite Example

Normal Stress in 3rd Ply, 45o to Bat Axis

CFRP Baseball bat with spiral CRFP reinforcement New in R14


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Defining Layers on Complex Geometries

For complex geometries, the ANSYS Composite PrepPost tool is used and layer definitions are imported in the assembly model in ANSYS Mechanical.

Courtesy of TU Chemnitz and GHOST Bikes GmbH


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ACP introduced as a component system inside WB

Like a typical WB system, file management and standard actions like Update, Duplicate

Consume materials from Engineering Data

Data Integrated ACP with WB New in R14


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ACP Pre system contains EDA, Geometry, Model and Setup (same as ‘Mechanical’ system)

Setup cell launches ACP Editor

Mesh (shell) is transferred from Mechanical into ACP

ACP then passes, discrete section data to Mechanical as ‘Imported Layered Section’ object

ACP-Mechanical Linkage New in R14


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ACP-Mechanical: Example Schematic

Implicit (MAPDL)

Explicit (Autodyn)

Parameter Support Include as part of Design

Exploration

New in R14


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You can define additional composite layers using the concept of fabrics, stackups and sub-laminates

Material Definition


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Complex Curved Structures

A system of rosette combination can be used to Define material reference directions

Manual definition


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Structures with high curvatures etc. produceability is a big factor in design

ACP can predict draping, fiber angle correction etc.

For Manufacturability, we can also interact with FiberSim (Vistagy)

Draping


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Verify model setup by viewing the stacking sequences or by generating a Ply-book

Validation

Cross-section views

Ply-Book generation


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ACP allows multi-orientations of the same region to support asymmetric laminate definition

Asymmetric Laminates


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tw(31) (0)

tw(31) (0)

tw(31) (0)

tw(31) (0)

State of the art post-processing

Identify critical parts by highlighting failure mode, failed layer and critical load case in one plot

Post-Processing


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VCCT

→In R14, ACP you can define a modeling-ply as a VCCT layer. When the solid-model is generated a VCCT layer is introduced between the corresponding plies.

Performance

→In R14, ACP now groups elements with similar or identical section-definition (based on limit-angle and –thickness). For most models this results in a drastic reduction of section-data which helps improve solver performance

Miscellaneous Enhancements New in R14


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Solid composites models


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Use CAD data to create cut-off rules

CAD data can be used to extrude plies from surface to SOLID mesh to model complex 3D shapes

Solid Extrusion


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In R13 ACP creates drop-off elements on all ply boundaries

With R14 ACP will now automatically collect non-overlapping plies and extrude them in one group in order to create smooth transition zones in between of them.

Auto Detect Butt-Joined Ply Boundaries

Three adjacent plies with intermediate drop-off elements (R13)

Three adjacent plies with smooth transition zone (R14)

New in R14


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In R14 ACP will detect free shared edges and automatically eliminate internal free edge ends to enable a fully automatic solid extrusion of a more general class of shell meshes.

Multi-Component Mesh extrusion

Three virtual components (R14)

Two-component tube assembly with two free shared edges

Solid extrusion in ACP 14 (illustration without butt-joined plies)

New in R14


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Appendix


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Explicit Solver Details Steps in ACP-Mechanical Workflow


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→Layered Shells (4 node/3 node shell)

→Orthotropic elasticity per layer or Isotropic elasticity + plasticity per layer

→Can have zero thickness ply's to represent ply drop offs

→Ply by Ply failure/progressive damage (based on Principal stress, strain or Tsai-Wu)

→Post-processing as per MAPDL plus display of failed layers for cases with progressive damage(via user defined results)

Layered Sections: Explicit Solver


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ACP-Mechanical Linkage- Mechanical Mesh

1) Create ACP Pre System 2) Specify Geometry Source 3) “Edit” Model Cell to open Mechanical 4) Create desired Named Selections for ACP 5) Mesh the Model


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ACP-Mechanical Linkage- Mechanical Transfer to ACP

1) Update the Model cell (to generate ACP Input file) 2) “Edit” Setup Cell to open ACP

Materials Transferred

Named Selections Transferred


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ACP-Mechanical Linkage-Imported Section Data back into Mechanical

1) Work in ACP to define the composite layups 2) “Update” ACP to generate imported Section

Data for Mechanical 3) Mechanical will then contain the Element by

element section data 4) Graphics, full structural Solver, and basic Post

Support inside Mechanical


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ACP-Mechanical Linkage- ACP Post

1) Create ACP Post System 2) Link from Structural Solution Cell into Post Results Cell to

transfer result file into ACP Post

Support for RMB “Transfer Data” actions to help user learn possible connections


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Shell Mesh sent to ACP. ACP extrudes into solids via CDB which can then be linked to MAPDL Component system.

ACP Post can be used to post-process the solid composites

ACP-MAPDL Linkage

ANSYS 14 Structural Mechanics Composites

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