### Define joints for a beam or truss study

```MEGN 424:
Computer Aided Engineering
LAB 6 - 2D Truss Analysis with
Slide1
Finite Element Analysis Process
1. Create a CAD model (completed in THW 3)
2. Configure and run an FEA study
3. Validate and understand the results
Slide2
Define Problem and Create Model
1. Create a CAD model (Completed in THW 3)
a. Define the problem to be studied
b. Specify units
c. Build a CAD model (in SolidWorks)
Slide3
2D Truss Structure FEA
3: (0,36)
2: (48,36)
2
750
3
y
1
x
1: (0,0)
Figure 1: A Simple 2D Truss Structure
(dimensions shown in inches)
Figure 2: Weldment profile crossSection (dimensions in inches)
• This system has three truss elements with the geometry shown.
• The three truss elements have a hollow rectangular x-sectional area of 2.089
in2 and wall thickness 0.25 in (shown on the right above).
• Use 1060 Aluminum alloy material
• The distance and coordinate units are inches.
• The x-translation is fixed at node 1, and the x- and y-translations are fixed at
node 3.
• The pin at node 2 is subject to an applied downward vertical force of 750 lbf.
Slide4
Open SolidWorks (SW), then open YI Truss LAB6.sldprt
from c:\scratch\yourinitials
Slide5
Configure and run FEA
2. Configure and run an FEA study
a. Choose a study type
b. Specify units
c. Define a mesh type
d. Define material
e. Define joints for a beam or truss study
f. Apply restraints
h. Define contact sets
i. Set meshing options
j. Mesh the part or assembly
k. Run the analysis
l. Create displays of results
Slide6
Select OK. You should see Simulation as a new tab in the
Slide7
Activate the Simulation tab near the top of the viewing
area.
Select Simulation (or Study Advisor) > New Study >
Static.
Name the study LAB6 your initials.
The software creates the study in the Simulation study tree.
Set the units in Simulation>Options>Default Options
tab to IPS units.
Slide8
Check Results Folders
Simulation>
Options
After saving the
file in
c:\scratch\your
initials
choose the
SolidWorks
document
folder.
It will
automatically
use c:\scratch\
Slide9
Check Reports Folders
Simulation>
Options
Select the
report folder.
It will
automatically
use
c:\scratch\your
Slide10
initials
Check Results Folder location
in the FEA Study
This should happen automatically
Slide11
Configure – Truss Elements
•
•
•
Select the structural
members, Right Click
Edit Definition
Choose Truss and OK
Slide12
Configure – Apply Material
Right click, Apply Aluminum:
1060 Alloy material to all
bodies
Slide13
Define joints
2. Configure and run an FEA study
a. Choose a study type
b. Specify units
c. Define a mesh type
d. Define material
e. Define joints for a beam or truss study
f. Apply restraints
h. Define contact sets
i. Set meshing options
j. Mesh the part or assembly
k. Run the analysis
l. Create displays of results
Slide14
Define the Joints (nodes)
Right click Joint Group
Slide15
Apply Restraints
2. Configure and run an FEA study
a. Choose a study type
b. Specify units
c. Define a mesh type
d. Define material
e. Define joints for a beam or truss study
f. Apply restraints
h. Define contact sets
i. Set meshing options
j. Mesh the part or assembly
k. Run the analysis
l. Create displays of results
Slide16
Apply Restraints (Fixtures)
3: (0,36)
2: (48,36)
2
750
3
y
1
x
1: (0,0)
Figure 1: A Simple 2D Truss System
(dimensions shown in inches)
Slide17
Apply z-Restraints to prevent rigid body motion
Select type: reference geom.
(Fixtures)


zero translation
to Front (z) Plane
Slide18
Apply x,y-Restraint to upper left Joint
Immovable Fixture = all translations fixed
Slide19
Apply x-Restraint to lower left Joint
Slide20
Check Restraints (Fixtures: Show All)
3: (0,36)
2: (48,36)
2
750
3
y
1
x
1: (0,0)
Figure 1: A Simple 2D Truss System
(dimensions shown in inches)
Slide21
2. Configure and run an FEA study
a. Choose a study type
b. Specify units
c. Define a mesh type
d. Define material
e. Define joints for a beam or truss study
f. Apply restraints
h. Define contact sets
i. Set meshing options
j. Mesh the part or assembly
k. Run the analysis
l. Create displays of results
Slide22
Slide23
Run and display results
2. Configure and run an FEA study
a. Choose a study type
b. Specify units
c. Define a mesh type
d. Define material
e. Define joints for a beam or truss study
f. Apply restraints
h. Run the analysis
i. Create displays of results
Slide24
Axial Stress Plot with probe values
Paste a screen shot of this plot into a MS Word document. See the following
slides for further LAB submission information.
Slide25
Verify and understand the results
3. Verify and understand the results
a. Use Mechanics of Materials (MOM)
fundamentals calculations to approximate
results
b. Verify the results
c. Understand the results
d. Assess the safety of the design
e. Report the results
Slide26
Draw a free body diagram
1. Do it on scratch paper. You don’t have to submit it.
2. Choose either compression or tension for each member.
3. Draw the force arrows at the end of each member for either tension or
compression.
4. Draw the reaction force arrows at each joint to be equal and opposite from
the force arrows at each end of the members.
5. Add symbols, dimensions, and force values.
F = -750 lbf
3 (0, 36)
3: (0,36)
F2
2: (48,36)
2
2 (48,36)
750
3
y
F3
1
F1
x
1 (0,0)
1: (0,0)
Slide27
Determine Forces
Determine R3y from the overall truss FBD
ΣFy = 0
ΣFy
R3y :== F0
R3y = 750 lbf
F = 750
R3ytension
= 750
Determine the internal
force
F3lbfin member
3 lbf
using the method
FR33y
:= :=
R3y
R3y 3
of joints:
F3 := R3y = 750 lbf
tension
F3
Determine internal forces F1 & F2 using the method of joints
applied to node 2:
F = -750 lbf
F1
F
=
3
5
F1 :=
5
3
 F = 1.25  10 lbf
3
compression
F2
2
3
F2
4
=
F1
5
4
3
F2 :=  F1 = 1  10 lbf
5
tension
F1
4
Slide28
Determine Stresses
A = 2.089 in2
σ1 :=
σ2 :=
σ3 :=
- F1
A
F2
A
F3
A
σ1 = -598.372 psi
Compressive stress
σ2 = 478.698 psi
Tensile stress
σ3 = 359.023 psi
Tensile stress
Slide29
Submit for LAB 6
1. MS Word file with: