In this webinar version of our live Night School events, Product Manager Glenn Whyte and Simulation Specialist Damon Tordini cover: - A walk-through of the stress analysis process: material definition, contacts and connections, loading, and fixtures - Generating and interpreting results - Productivity and automation tools that get you to a better design, faster and more efficiently - Troubleshooting steps and solutions for common problems - An overview of the Flow Simulation process, and answers to common questions Join the webinar here: http://www.hawkridgesys.com/events/live-product-webinars/solidworks-simulation-night-school-online-2014/

1. 1
3DS.COM©DassaultSystèmes|ConfidentialInformation|7/21/2014|ref.:3DS_Document_2012
Simulation Night School 2014
Glenn Whyte + Damon Tordini
Simulation Specialists

2. 2
Simulation Night School Agenda
Overview/SimulationXpress
The Analysis Process
Results and Result Interpretation
Intermission
Common Problems/Troubleshooting
SOLIDWORKS Flow Simulation

3. 3
Computer Specs
HP EliteBook 8570w Laptop
Windows 7 Professional x64 Edition
Intel i7 3630QM (2.6 GHz)
4 computing cores
8 GB RAM
nVidia Quadro K1000M (2GB)
SOLIDWORKS 2014 SP4.0 x64
SSD Hard Drive

4. 4
Overview of Simulation tools for everyone
Linear Static Stress Analysis
Simulation Xpress

5. 5
Linear Static Stress Analysis
Key Assumptions:
• Loads applied slowly, no inertia, no time-dependence etc.
• Dynamic analysis overcomes this assumption
• Linear material behavior
• Small deformations – constant stiffness matrix
• Nonlinear Analysis overcomes this assumption

6. 6
Matching Real-Life Results: Study Type
Linear Nonlinear
Static
Dynamic

7. 7
Stress/Strain Curves

8. 8
SOLIDWORKS SimulationXpress
Limitations:
• Linear static stress analysis on single-body parts.
• Uniformly distributed force or pressure loading
• Fixed-face restraints
• Global control of mesh density
• Result plots of Von Mises stress, displacement, and FOS
• Single-factor optimization

9. 9
SOLIDWORKS Analysis Products
SOLIDWORKS Simulation Premium
SOLIDWORKS Simulation Professional
Static
Frequency
& Buckling
Thermal Drop Test
Fatigue
Motion
Simulation
Optimization
Pressure
Vessel
Flow
Simulation
Electronic
Cooling Module
HVAC Module
Nonlinear
(static & dynamic)
Harmonic
Random
Vibration
Time History
Composites
Response
Spectra
Sustainability
Plastics
Professional
Premium
Advanced

10. 10
Building the FEA Model

11. 11
Analysis Process and Considerations
Material
Definition
Contact
Connectors
Fixtures
Loads
Meshing
Solving
Results/Post
Processing

12. 12
Materials Definition
• Start your mathematical
problem with a strong base.
• Common area of mistakes in
FEA problems
• The source for SOLIDWORKS
material properties is Metals
Handbook Desk Edition (2nd
Edition), ASM International.

13. 13
Custom Materials
•The default SOLIDWORKS material database cannot be
modified. This is by design.
•When creating a custom material, it is recommended to copy
an existing (similar) material, and modify.

14. 14
Elastic
Modulus
Poisson’s
Ratio
Yield
Strength
Density
SOLIDWORKS Material Library
Required for Linear
Static

15. 15
Meshing
Automatic Mesh Type Selection
Sheetmetal/Surfaces
Shell Mesh
Weldments
Beam
Everything Else
Solid Mesh

16. 16
Solid Elements
•Basic shape is a tetrahedron
•High Quality (default) Solid Elements will have 10
nodes: 4 corner nodes and 6 mid-side nodes. Edges
of HQ elements can better map curvilinear shapes.
•Draft Quality Solid Elements have 4 corner nodes
and linear edges.
•For both cases, each node has three degrees of
freedom, all translational.
Nodes
Draft High
Nodes 4 10
DOF per
node
3 3
Total DOF 12 30

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Shell Elements
•Used for thin geometry
•Basic shape is a triangle
•High quality (default) Shell elements have 6 nodes: 3 corner
and 3 mid-side with 6 DOF per node (including rotational
freedom). Can better map to curvilinear shapes.
•Draft quality Shell elements have 3 nodes (corners only), with
6 DOF per node. They remain linear through deformation.
Draft High
Nodes 3 6
DOF per node 6 6
Total DOF 18 36

18. 18
Element Quality
Draft quality mesh will create an
analysis with the same fundamental
mesh structure, but less nodes/DOFs
Stress results will likely not be
accurate enough for final results
However, draft mesh is an excellent
tool for model preparation or
troubleshooting

19. 19
Why Use Shell Elements?
•Any model could be meshed with Solid Elements. However, to
get an adequate mesh for thin objects, the number of elements
can become unmanageable. More DOF = Longer Solve Time!
0
50000
100000
150000
200000
250000
300000
350000
1500 2500 3500 4500
Degreesof
Freedom
Von Mises Stress

20. 20
Beam Elements
•Used for slender objects with a constant cross-sectional
shape
• As of SOLIDWORKS 2011, tapered beams also supported
•Basic shape is a line element with two end points (nodes)
• Each node has 6 degrees of freedom; 3 translations and 3
rotations.
Nodes 2
DOF per node 6
Total DOF 12
Nodes

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Invalid for Beam Elements
•Beam elements support tapered
beams, but cross-section can only
shrink or grow proportionally
•For other invalid beams, see the
help file article titled: “Invalid
Tapered Beams”

22. 22
Contact
No
Penetration
Bonded
Virtual
Wall
Shrink Fit

23. 23
Contact/Gap Hierarchy

24. 24
Global Contact
•Bonded- Selected components or bodies behave as if they
were welded during simulation (no relative translation or
rotation).
•Allow Penetration – Selected components or bodies may
pass through each other.
•No Penetration-Selected components or bodies do not
penetrate each other during simulation. Surface to surface
contact formulation is applied by default.

25. 25
Global Contact Limitations
•Global contact will only be applied to
faces/entities that are coincident at the
start of the analysis.
(2014 allows some non-touching faces
in global contact, but have had limited
success with this function)
•Mixed mesh types: global bonded
contact does not always automatically
create connections
•Solution: Local Contact Sets!

26. 26
Contact Tools and Tips
• Interference detection – “Treat coincidence as interference”
does a great job of showing where parts are initially touching
• Contact Visualization Plot – New in SW2014, allows you to
visualize what contact has been created, and what type.
• Solver-based contact visualization will show contact
relationships between mesh elements.

27. 27
Bolts
Standard or Counterbore
with Nut
Countersink with Nut
Standard or Counterbore
Screw
Countersink Screw
Foundation Bolt

28. 28
Fixtures
 Used to represent how the given model is
attached to the rest of the world
– Fixed on a Surface, Edge or Point
– Free Sliding or Rotation
 Helpful for reducing the size of the problem
to a component level or subassembly level
 Ensures the problem is in static equilibrium
 Remove DOF in the model

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Degrees of Freedom
• Objects in 3-D space have 6 degrees of freedom (DOF)
•In Cartesian coordinates, there are:
•Three translational (x,y,z)
•Three rotational (about x, about y, about z)
• In SOLIDWORKS Simulation, the conditions of the
problem (fixtures, contact, mesh) determine how many
total DOF exist
• More DOF means a more complex problem,
requiring more computer resources

30. 30
Fixture Types
Standard
• Fixed Geometry
• Roller/Slider
• Fixed Hinge
Advanced
• Symmetry
• Circular Symmetry
• Use Reference Geometry
• On Flat Faces
• On Cylindrical Faces
• On Spherical Faces
• Bearing

31. 31
Fixtures Preview
Translation
Rotation

32. 32
No Fixtures Preview?

33. 33
Loads
Standard
• Force
• Torque
• Pressure
• Gravity
• Centrifugal
• Bearing Load
• Temperature
Imported
• Flow Effects
• Thermal
Effects
Other
• Remote Load
• Remote Mass
• Distributed
Mass

34. 34
Force vs. Pressure
Both are external loads intended to represent other components or
environmental conditions acting upon your design.
Force Pressure
Defined in units of force (lbf, N) Defined in units of force per area (psi, N/m2)
Can be applied to faces, edges and
vertices
Can only be applied to faces
Can be applied normal to face or in
specified direction
Can be applied normal to face or in specified
direction
Components can be defined in all 3
vectors (local x,y,z)
Can only be defined in one vector
By default, Force values are distributed across the selected
geometry, while Pressure values are constant over the selected
geometry

35. 35
Force vs. Pressure.
Forces and Pressures can both represent the same load depending
on how you define them!
100 lbf / 1 in2 = 100 psi
100 psi * 1 in2 = 100 lbf

36. 36
Remote Mass vs. Distributed Mass
Two differences:
1. Remote mass adds stiffness to the model
as the component being replaced by the
remote mass is considered to be attached
by rigid bars.
2. The remote mass can have a non-uniform
distribution whereas the distributed mass
is always uniformly applied.
Please note: "Treat as remote mass" only considers
mass…so be sure to define gravity!

37. 37
Mesh Creation Tools
• Two mesh creation schemes – Standard and Curvature-Based
• Generally, Curvature-Based will create more elements, but better adapt
to complex geometry
• Curvature-based mesher takes greater advantage of multi-core CPUs
Standard Curvature
Elements 109 258 70 752
Time to Mesh 33 seconds 9 seconds
Percentage of distorted
elements
0.215 % 0.543 %
Mesh Control needed 133 faces 0 faces
• Mesh controls allow you to specify a smaller mesh resolution
for specific vertices, edges, faces, bodies or components

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Challenge Question: Mesh Options
•Which mesh options will give the most accurate result?
•Which will be the quickest to solve?
Max Von Mises (psi) Time to
(s)
Standard Mesher
Curvature-Based
Mesher
Standard Mesher
with Mesh Control
“True” Result

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Challenge Question: Mesh Options
•Which mesh options will give the most accurate result?
•Which will be the quickest to solve?
Max Von Mises (psi) Time (s)
Standard Mesher 2,354 4
Curvature-Based
Mesher
2,557 14
Standard Mesher
with Mesh Control
2,688 8
“True” Result 3,241

40. 40
Solving
FFEPlus – Uses an iterative approach to solve the equations
Direct Sparse – Directly solves the system of equations
Direct Sparse Large Problem DS FFEPlus
More efficient with No
Penetration Contact
Similar to direct
sparse with less
memory load
More efficient with
large problems, ie.
>250k DOFs
Uses more RAM for larger
problems, around 10x
more than FFEPlus
Efficient for large
problems, with good
multi-core capability
Better equipped to utilize
multiple cores
Better with significant
differences in materials

41. 41
Results and Result Interpretation
Result Quantities Available
Result Viewing Options
Failure Theories

42. 42
Result Quantities Available
• Stress
• Stress in X, Y, Z
• Shear stress about X, Y, Z
• Principal Stresses - 1, 2, 3
• Von Mises
• Stress Intensity (P1-P3)
• Energy Norm Error
• Contact Pressure
• Displacement
• Displacement in X, Y, Z, and resultant
• Reaction Forces
• Strain
• Strain in X, Y, Z, resultant
• Shear Strain about X, Y, Z
• Principal Strains
• Strain Energy Density

43. 43
Result Plots Available
• Contour Plots
• Section Clipping
• Iso-Clipping
• Probe
• List Results
• Reaction Forces/Free body forces
• Options, Settings and Definitions
• Now streamlined in 2014!

44. 44
Failure Theories
Factor of safety plots can be viewed to show how the stresses
related to different failure theories compare to failure limits.
• For ductile metals (and also other situations)
• Von Mises
• Tresca (maximum shear stress)
• Von Mises is more commonly used, Tresca is more
conservative
• For brittle materials – Mohr Coulomb Stress theory/internal
friction

45. 45
Coming Soon to HawkWare Tools
Simulation Results Manager!
• Archive completed study results to
save disk space
• Clean up results directories for easier
sharing
Visit store.hawkridgesys.com for more
information

46. 46
Common Problems/Troubleshooting
Results Convergence
Matching Real-Life Results

47. 47
Mesh Convergence Practices
In stress analysis the quality of the result is directly dependent on the
quality of the mesh.
No stress result should be accepted as “correct” until you’ve proved that
the mesh is adequate.
This is done by proving that the stress results are “converged”

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What is Convergence?
• All FEA analysis is based on the concept of
discretization- breaking a model into individual pieces
that can be calculated (meshing).
• This inherently adds error to results- convergence is
the process of reducing mesh error

49. 49
Checking Strategies
Methods:
1. Manual Inspection
a) Run a Study > Refine Mesh > Review
Results (stress)
b) Utilize Trend Tracker
2. Design Study
a) Create a parameter linked to mesh
control or Global mesh size
b) Manually specify sizes or use
Optimization
3. Adaptive Meshing

50. 50
Checking Convergence – Manual Inspection
1. Run an analysis
2. Increase mesh density (either globally or locally)
3. Review key results
4. Repeat until key results don’t change within an acceptable
tolerance

51. 51
Checking Convergence – Adaptive Meshing
•The h-Method
•The concept of the h-method is to use smaller elements.
After running the study and estimating errors, the software
automatically reduces the element size in appropriate
areas.
•The p-Method
•The concept of the p-method is to add more nodes and
increasing the order of the element in regions with high
errors. After running analysis and estimating errors, the
program increases the order of elements in regions where
necessary.

52. Adaptive Finite Element Analysis
h-Adaptivity, p-Adaptivity
Refining the mesh (h-Adaptivity)
Changing the “order” of elements (p-
Adaptivity)
1st order
(Draft Quality)
2nd order
(High Quality)
… 5th order

53. 53
Concentrations & Singularities
No Singularity Singularities
No sharp geometrical discontinuity and
no concentrated load/fixture
Sharp geometrical discontinuity or
concentrated load/fixture
Will converge when mesh is refined Will not converge with refinement
Converged stress value can be trusted Stress values cannot be trusted
•Stress concentrations are areas of high stress
•Stress singularities are a type of concentration that displays
unrealistically high stress values due to mathematical phenomena
(displacements are not affected)
•Singularities generally occur in sharp corners

54. 54
Hawk Ridge Systems Knowledge Base
For more details on recommended
procedures and the mathematics behind
convergence, check out our guide at:
support.hawkridgesys.com/forums

55. 55
Matching Real-Life Results
•What are the SOLIDWORKS Simulation results
being compared to?
-Hand calculations?
-Experimental results?
-Other software?

56. 56
Hand Calculation Example
Stress/Strain calculation used to evaluate deformation of tank wall
under pressure
Formula predicts 0.485in, SOLIDWORKS predicts 0.501in for a single
plate.
However, once you add the other 3 walls, displacement is 0.19in
The 3d case is closer to fixed support than simple support.

57. 57
Matching Real-Life Results: Conditions
•Are you comparing to physical tests,
or real-world usage?
•Do you have a document that
explains the experiment setup?
•What materials are being used? Do
the mechanical properties of your
material match that which is found in
the SOLIDWORKS material
database?
•How realistic are your
restraints/fixtures?

58. 58
Matching Real-Life Results: Loads
•Are you running the correct study? A static load
of value x may cause an object to react much
different than an impact load of value x.
•Are there other factors that you are omitting in
your analysis?
•Gravity
•Friction
•Damping

59. 59
Matching Real-Life Results: Study Type
Linear Nonlinear
Static SOLIDWORKS Premium Simulation Premium
Dynamic Simulation Premium Simulation Premium

60. 61
Where is error introduced?
5% 10% 65% 20%
<1%

61. 62
How to have confidence in results?
Validation examples
NAFEMS is an independent, not-for-profit organization
that sets and maintains standards in computer-
aided engineering analysis and, specifically, finite
element analysis (FEA).

62. 63
Matching Real-Life Results
• Remember: when using FEA, the end goal should not
always be to duplicate real world results.
• Garbage in, garbage out
• Significant value can come when using it to get relative
results (Trend studies, design decisions).

63. 64
SOLIDWORKS Flow Simulation
What is Flow Simulation?
• Embedded CFD (Computational Fluid Dynamics) analysis
tool inside SOLIDWORKS
• Evaluate designs for optimum flow rates, temperatures,
aerodynamics, and more
• Piping Systems
• Electronics Cooling
• Heat Exchangers
• Transportation

64. 65
Flow Simulation Procedure
Geometry Prep
Wizard
Boundary
Conditions
Materials/Heat
Sources/etc.
Goals
Solving
Results/Post
Processing

65. 66
Flow Simulation: Geometry Prep
•Simplify Geometry- not mandatory, but
usually smart
•Internal or External analysis?
•Check Solid/Fluid Volume
•Use Leak Tracker

66. 67
Flow Simulation: Boundary Conditions
•Important mainly for internal analyses
•Establish where fluid enters or leaves the
model
•Flow Openings: known inlet or outlet
condition
•Pressure openings: ?
•Applied to lids
•Always select inside face(s)

67. 68
Flow Simulation: Materials/Heat Sources/Etc.
•Important mainly for simulations with Heat
Conduction in Solids enabled.
•Many optional conditions: Two Resistor
Components*, Perforated Plates, Printed
Circuit Boards*
•Typical properties to enter:
•Thermal Conductivity, W/m2-K
•Heat Power, W
•No. of PCB layers
•Note: materials in Flow Simulation are
different than in SOLIDWORKS Material
library!
*Requires Electronics Cooling Add-on

68. 69
CircuitWorks and Flow Simulation
New for 2014: Import the following ECAD properties from
CircuitWorks to Flow Simulation:
• Heat Sources
• Conductivity
• Dielectric and Conductor Density
• Specific Heat
• Printed Circuit Board properties with the Electronic Cooling Module

69. 70
Flow Simulation: Goals & Solving
•Goals allow easy checking of key results
both during and after the simulation
•Verify what you’re trying to measure:
average vs. bulk average
•Ensure a certain level of accuracy in the
solver- “convergence”
•Solver can be run on local machine, or
on network- will use all available CPU
cores

70. 71
Flow Simulation: Results
•Both numerical and visual results are available to evaluate
design
Typical workflow:
1. Check if requirements are met via Goals, surface
parameters, etc.
1. Max CPU Temp? Pressure Drop?
2. Use Cut Plots, Surface Plots, Flow Trajectories to see
why, and how design should be modified.

71. 72
Hawk Ridge Online Training
• 8 current Simulation course offerings via GoToMeeting
• Visit www.hawkridgesys.com/training for more information

72. 73
Simulation Services
► One-On-One Mentoring
As an extension to our classroom training,
Mentoring provides customized training on
applying SOLIDWORKS Simulation tools to your
specific engineering problem.
► Analysis Consulting
Leverage the engineering and analysis expertise, experience and resources of our
team to execute your analysis.
► HRS Simulation Services Credit
25% of your simulation services fees can be applied to new SOLIDWORKS
Simulation software license purchases.
► Contact
Your Hawk Ridge Systems contact or Jared Conway, Simulation Services Manager
(jared@hawkridgesys.com, 650-230-7006).

73. Thank you for
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