Topology & Geometry Manipulation in HyperMesh: Understanding Collectors, Repair, & Refinem, Notas de estudo de Engenharia Mecânica

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Altair HyperWorks 10.

Introduction to HyperMesh

Day 1

Adriano A. Koga

Getting Started

Opening and Saving Files

Working with Panels

Organizing a Model

Controlling the Display

Chapter 1: HyperMesh Introduction

Panels: General Layout

Some sub-panels are organized in columns

Each column is a different method

Work from top to bottom in the relevant column

• Example: surface edit : trim with surfs/plane sub-panel

1) What to do:

Pick a sub-panel

for the function

to be used

3) What to do

it to:

Select entities

that will be

affected

4) How to do it:

Give parameters

that define how

the function will

be executed

5) Do the

action:

Execute the

function

2) Method to

use:

Work in the

appropriate

column

Model Organization: HyperMesh Entity Types

Geometry

Points

Lines

Surfaces

Solids

Connectors (used for welding)

FE Model

Nodes

Temp Nodes (marks a node with a small circle)

Elements

Points

Lines

Surfaces

Nodes Elements

Temp Nodes

Solids

Model Organization: HyperMesh Entity Types

Coordinate Entities

Systems (coordinate axes)

Vectors

Reference Entities

Sets (a simple list of a particular type of

entity)

Blocks (a list of entities contained within a

box shape)

1D Element Cross Sections

Beam Sections (cross sectional

properties for a property collector)

Systems

Beam Section

Vectors

Model Organization: Collectors

The HyperMesh model is organized using “collectors”

There are many types of collectors

Most entities in HyperMesh must be placed in a collector

Each collector type holds a specific type of entity

Collector Types Can contain entity types:

Component Elements, Points, Lines, Surfaces, Connectors

Multibody Ellipsoids, Mbjoints, Mbplanes, Sensors

Assembly Components, Multibodies, Assemblies

Load Collector Loads, Equations

Material

none (materials and properties don’t contain other entities but are

still treated as collectors)

Property

System Collector Systems

Vector Collector Vectors

Beam Section Collector Beam Sections

Model Organization: Collectors

Model browser

View collectors and assemblies in a hierarchical

tree format

Create, delete, and rename collectors

Edit collector attributes

Organize collectors into assemblies

• Drag and drop

Right-Click on

Collector for

advanced

options

Model Organization: Collectors

New entities are created in the “current collector”

Creating a new collector automatically sets the current collector to that new

collector

Model Browser or can be used to change the current collector.

Include Browser can be used to change the current include.

Organize panel can be used to move entities into a different collector

Bold “Current Collector”

Bold “Current Include”

Display Control: Viewing: Toolbar

Pan

Center (C)

Rotate Left

Rotate Right

Rotate Up

Rotate Down

Rotate Clockwise

Rotate Counter Clockwise

Dynamic Rotate (A)

Dynamic Spin (R)

Manually rotate by “grabbing” a point and dragging

Rotate relative to the mouse cursor and screen center

Pan the model

Select and click on the screen to re-center model in

graphics window

Incremental rotations in respective directions

Importing and Repairing CAD

Generating Midsurface

Simplifying Geometry

Refining Topology to Achieve a Quality

Mesh

Chapter 2: Geometry Cleanup

Topology Repair: Surface Definitions

Fixed point (“Surface vertex”)

• Point associated with a surface
• Cannot be moved off the surface
• Can lie on a surface edge or the

“interior” of a surface

• Separates surface edges from each

other

• Forces a node to be placed at that

location during meshing

Surface edge

• Line associated with a surface
• Defines a surface’s boundary
• Cannot be moved off the surface
• Has a fixed point on both ends

Surface

Automeshing: What is “topology”?

Topology” is how surfaces connect to adjacent surfaces of a part

Surface connectivity is controlled by the associated surface edges

If a surface edge is associated with more than 1 surface, those surfaces are

considered to be connected (“equivalenced”)

Surface edges are categorized, named, and colored according to the number of

associated surfaces:

Free edge (red)

• Associated with only 1

surface

• Surfaces with a free edge

between them are NOT

equivalenced at that edge

Shared edge (green)

• Associated with 2 surfaces
• Surfaces are equivalenced

Suppressed edge (blue)

• Surfaces are treated as though

combined into 1 surface

T-junction edge (yellow)

• Associated with 3 or more

surfaces

• Example: surfaces forming a

T-connection

• Surfaces are equivalenced

Topology Repair: Viewing Topology

Toolbar > > Topology tab controls display of:

• Visibility of free, shared, t-junctions, and suppressed edges

Visibility of fixed points

Level of surface transparency

Topology Repair: What is it?

HyperMesh will attempt to properly clean up surfaces during import

Some types of geometry files have surface connectivity information which helps

HyperMesh. Typically native geometry files like Catia, UG, ProE, etc.

Geometry usually imports cleanly

Topology Repair consists of correcting connectivity errors between

adjacent surfaces

Possible errors include:

• Unconnected adjacent surfaces
• Duplicate surfaces
• Missing surfaces

The Goal of Topology Repair: Restore the surface data to a perfectly

clean representation of the part