16 boxbm transient pat301

8/2/2019 16 Boxbm Transient PAT301

1/44

WS17-1

PAT301, Workshop 17, December 2005

Copyright 2005 MSC.Software Corporation

WORKSHOP 17

BOX BEAM WITH TRANSIENT LOAD


2/44


3/44

WS17-3



Workshop Objectives

Perform a modal analysis for a linear dynamic model. Also,perform a linear transient analysis for the model. View theshape of the model over time. Create an X vs Y plot ofdisplacement vs time.

Problem Description Perform modal and transient analysis of plate element model

Cantilevered beam properties: include four concentrated

masses Transient load on tip of cantilevered beam = constant tip force *

function of time (f(t))

Software Version MSC.Patran 2005r2

MSC.Nastran 2005r2b


4/44

WS17-4



Key Concepts and Steps:

Database: open an existing MSC.Patran database for cantilevered beam

with static loading at free end of beam.

Elements: add four concentrated masses at free end of beam

Loads/BCs: modify static loading to constant force * f(t) Properties: define the 0D elements as CONM2 elements

Load Cases: create a time dependent field

Fields: create a non-spatial field for f(t)

Analysis: Solution Type = Nastran Normal Modes, Solution Sequence =103, Method = Full Run

Results: display the deformed shape (mode shape) for some normal modes

Analysis: Solution Type = Nastran Transient Response, Solution Sequence

= 112, Method = Full Run Results: display the structural shape over time, and displacement vs time

for some nodes


5/44

WS17-5



Step 1. Open Database cant_beam_transient.db

Open database.

a. File / Open.

b. Select cant_beam_transient.

c. Click OK.

b

c

a

NOTE: warning message $# Journal file: cant_beam_transient.db.jou does not exist is

created. This is not a problem. A journal file does notexist for this database because one was not created

when creating this database, i.e. File / Save a Copy

has a toggle Save Journal File Copy Also.


6/44

WS17-6



Step 2. Add Concentrated Masses to the Four Corners

Select the four corners of the

concentrated mass.

a. Elements: Create / Element /Edit.

b. Shape: Point.

c. Topology: Point.

d. Turn Auto Execute off.

e. Click on Node 1 = and

select the four nodes at thecorners of the free end of

the beam.

f. Click Apply.

Zoomeda

b

c

e

Add concentrated masses to

the four corners of the boxbeam at its free

(unconstrained) end. This is

done to create low frequency

modes that are predominantly

similar to beam bending in

nature.

Small triangles are drawn at the

nodes where the mass is created.

e

Note that node numbers may not be

identical when performing this exercise.

d

f


7/44

WS17-7



Step 2. Add Concentrated Masses to the Four Corners (Cont.)

Specify the mass of each of the

four concentrated masses.

a. Properties: Create / 0D /

Mass.

b. Entermass_prop for theProperty Set Name:.

c. Option(s): Lumped.

d. Click on Input Properties.e. Specify Mass as 0.65.

f. Click OK.

g. Click in Select Members

under Application Region.

h. Select Point element icon

in the picking filter menu.i. Select the four 0D mass

elements at the free end of

the beam.

j. Click Add.

k. Click Apply.

a

b

c

d

e

g

h

i

j

k

h


8/44

WS17-8



Step 3. Create a Group with Subset of Elements

Create a group with subset of

elements

a. Group / Create.

b. Entersubset_elm underNewGroup Name.

c. Check Make Current.

d. Group Contents: Add EntitySelection.

e. Select Entity Selection and

select a row of elements going

from one end to the other as

shown in the figure.

f. Click on Apply.

a

bc

d

e

f

e

The stresses will be calculated only for

elements in this group. This will reduce the

amount of calculations done, compared to

doing it for the set of all elements.

S C G S f (C )


9/44

WS17-9



Step 3. Create a Group with Subset of Elements (Cont.)

Include the nodes corresponding to

elements in the group subset_elma. Tools / List / Create.

b. Set the

Model/Object/Methodto

FEM/Node/Association.

c. Association: Element.

d. Click on Target List: A.

e. Select on Elementand

select the same row of

elements going from one

end to the other just as done

in the previous page.

f. Click on Apply.g. Add the list of nodes to the

group subset_elm by

selecting Add to Group.

h. Click on Apply.

aThe list of nodes will be placed

in the dialogue List A.

g

h

d

f

b

c

e

St 4 P t G b t l


10/44

WS17-10



Step 4. Post Group subset_elm

Post group subset_elm.

a. Group / Post.

b. Select subset_elm underSelect Groups to Post.

c. Click on Apply.

a

b

c

St 4 P t G b t l (C t )


11/44

WS17-11



Step 4. Post Group subset_elm (Cont.)

Display both the element and

node labels.

a. Display / Finite Elements.

b. Show All FEM Labels.

c. Click on Apply.

Display the entire model.

a. Group / Post.

b. Select default_groupunderSelect Groups to

Post.

c. Click on Apply.

d. Turn off all labels.

a

b

c

g

This also can be done

using Label Control icon.


12/44

Step 5 Create and Post Non Spatial Field (Cont )


13/44

WS17-13



Step 5. Create and Post Non-Spatial Field (Cont.)

Continue to create a non-spatial

field(function) that will be used asthe multiplier for the applied force.

a. Select row 29 forTime(t),

and enter1.1 in Input ScalarData. Press Enteron thekeyboard.

b. Select row 30 forTime(t),and enter3.0 in Input ScalarData. Press Enter.

c. Enter0.0 forValue in row 29and 30.

d. Click on OK.

e. Click on Apply.

d

c

a

b

Step 5 Create and Post Non Spatial Field (Cont )


14/44

WS17-14




a. Fields: Show.

b. Select delta_force underSelect Field To Show.

c. Select Specific Range.

d. Minimum: 0.0.

e. Maximum: 3.0.

f. No. of Points: 30.

g. OK.

h. Check Post XY Plot.

i. Click on Apply.

a

b

d

c

e f

g

i

h

Step 5 Create and Post Non-Spatial Field (Cont )


15/44

WS17-15




a. Click on Cancel.

a

Step 6 Create a Time Dependent Load Case


16/44

WS17-16



Step 6. Create a Time Dependent Load Case

Create time dependent load case

needed for time dependent loadcreation.

a. Load Cases : Create.

b. EnterTransient_1c underLoad Case Name.

c. Click on Make Current.

d. Load Case Type : TimeDependent.

e. Click on Apply.

a

bc

d

e

Step 7 Modify the Applied Force


17/44

WS17-17



Step 7. Modify the Applied Force

Modify the force to include t (time).

a. Loads/BCs: Modify / Force /Nodal.

b. Current Load Case:

Transient_1c. (Type: TimeDependent)

c. Select force underSelectSet to Modify.

d. Modify Data.

e. Change to

in Force.

f. Click in * Time/Freq.

Dependence and selectdelta_force underTime/Freq. Dependent

Fields.

g. Click on OK.

h. Click on Apply.

a

b

c

d

f

g

h

e

f

NOTE: the spatial and time dependentfunctions are multiplied, e.g.

* f:delta_force. Make

sure that force is assigned to LoadCase Transient_1c.

Step 8. Modal Analysis


18/44

WS17-18



Step 8. Modal Analysis

Create the Load Case to be

analyzeda. Load Cases: Create.

b. Load Case Name: modal.

c. Load Case Type: Static.

d. Click on Assign/PrioritizeLoads/BCs.

e. fix_end is to be includedunderAssigned Loads/BCs.

To do this select on

Displ_fix_end underLoads/BCs Selection.

f. Click on OK.

g. Click on Apply.

a

b

c

d

f

e

e

Step 8. Modal Analysis (Cont.)


19/44

WS17-19




Create job to analyze.a. Analysis: Analyze / Entire

Model / Full Run.

b. Enter

cant_beam_subset_modal_1 for the job name.

c. Solution Type.d. Select NORMAL MODES.

e. Click on OK.

f. Click on Subcases.

a

b

c

d

e

f



20/44

WS17-20



p y ( )

Continue to create the job for the

modal analysis.

a. Select modal under

Available Subcases.

b. Select modal underAvailable Load Cases.

c. Subcase Parameters.

d. Extraction Method: Lanczos.

e. Lower = 0.0(Hz).

f. Upper = 100.0(Hz).

g. Click on OK.

h. Click on Apply.

i. Click on Cancel.

a

b

d

e

f

g

h

c

i


21/44



22/44

WS17-22



p y ( )

Attach XDB File.a. Analysis: Access Results /

Attach XDB / Result Entities.

b. Click on Select ResultsFile.

c. Select and attach the file

cant_beam_subset_modal_1.xdb.

d. Click on OK.

e. Click on Apply.

a

b

c

d

e



23/44

WS17-23



Create deformation display for the

first mode.a. Results: Create /

Deformation.

b. Select MODAL, A2:Mode1:Freq.=13.441 underSelect Result Case(s).

c. Select Eigenvectors,Translational underSelectDeformation Result.

d. Show As: Resultant.

e. Click on Apply.

a

b

c

d



24/44

WS17-24



Create deformation display forother modes.

a. Select MODAL,A2:Mode2:Freq.=17.879 underSelect Result Case(s).

b. Click on Apply.c. Select MODAL,

A2:Mode3:Freq.=21.082 underSelect Result Case(s).

d. Click on Apply.

Step 9. Run the Transient Simulation


25/44

WS17-25



Before setting-up the simulation

under Analysis it is necessary tospecify the loads and boundary

conditions under Load Cases

a. Load Cases: Modify

b. Select the load case

Transient_1c underSelect

Load Case to Modify.c. The Loads/BCs

fix_end(constraint) andforce(time varying) must bespecified underAssigned

Loads/BCs. This can be

done by selecting them

underLoads/BCs

Selection(upper-left).

d. Click on OK.

e. Click on Apply.

a

b

c

Step 9. Run the Transient Simulation (Cont.)


26/44

WS17-26



Run the Transient Simulation.

a. Analysis: Analyze / Entire

Model / Full Run.b. Enter Job Name

cant_beam_subset_elm

c. Select Solution Type.

d. Choose TRANSIENTRESPONSE forSolution Type.

e. Formulation: Modal.

f. Click on SolutionParameters.

g. Eigenvalue Extraction.

h. Extraction Method: Lanczos.

i. Lower = 0.0 (Hz).

j. Upper = 100.0 (Hz).

k. Number of Desired Roots = 10.

l. Click on OK.

m. Click on OK.

n. Click on OK.

b

c

d

e

f

g

h

ij

k

l

m

a



27/44

WS17-27



Create transient loading subcase.

a. Select Subcases.

b. Solution Sequence: 112.

c. Action: Create.

d. Select Transient_1c underAvailable Subcases.

Automatically Transient_1c

should highlighted underAvailable Load Cases.

e. Subcase Parameters.

f. Select DEFINE TIMESTEPS.

g. No. of Time Steps = 3000.

h. Delta-T = 0.001.i. Click on OK.

j. Modal Damping: Crit.Damp. (CRIT).

k. DEFINE MODAL DAMPING.

l. Click on Add Row.

m. Enter0.0 and 100.0 forFrequency, 0.025 for bothValues.

n. Click on OK.

o. Click on OK.

b

c

d

e

f

g h

i

j

k



28/44

WS17-28



Select the output Requests.

a. Select Output Requests.b. Form Type: Advanced.

c. Select Element StressesunderSelect Result Type.

d. Select

STRESS(SORT)=ALL

FEM, underOutputRequests and make sure

that Displacement and

SPCForces requests appear

as well.

e. Now, choose subset_elmunderSelect Group(s)/SET.

This will change the Output

Request to

STRESS(SORT)=subset_elm,

f. In Options: select ByFreq/Time forSorting.

g. Click on OK.

h. Click on Apply.

i. Click on Cancel.

b

c

d

e

f

g

a



29/44

WS17-29



Select Subcase.

a. Select Subcase Select.

b. UnderSubcases Selected,only the desired subcase,

Transient_1c shouldappear. This can be

achieved by selecting names

in the upper and lower

boxes.

c. Click on OK.

d. Click on Apply.

a

b

c

d

Step 10. Access Results Under Analysis


30/44

WS17-30



Attach transient results XDB file.a. Analysis : Access Results /

Attach XDB / Result Entities.

b. Click on Select Results File.

c. Select and attach the file

cant_beam_subset_elm.xdb.

d. Click on OK.e. Click on Apply.

a

c

d

b

e

Step 11. View the Transient Deformation Results


31/44

WS17-31



View time dependent deformation

results at a single time.

a. Results : Create /Deformation.

b. Click on the View Subcases

icon.

c. Select

TRANSIENTTime=0.154

underSelect Result Case(s).

d. Select Displacements,Translational underSelectDeformation Result.

e. Show As: Resultant.

f. Click on Apply.

g. Show As: Component.

h. SelectYY only.

i. Click on Apply.

j. Look at other individual

times.The title in the upper left

corner of the viewport

gives the time and result

type.

a

c

d

b

e

Step 11. View the Transient Deformation Results (Cont.)


32/44

WS17-32



Next, look at how the model deforms

with time.

a. Results: Create / Deformation.

b. For the View Subcases icon

not depressed, select all thetransient subcases underSelect Result Case(s) using

the shift key. Or, can select all

or a subset of the transient

result cases by selecting the

View Subcases icon (see nextpage).

c. Select Displacements,Translational underSelect

Deformation Result.d. Show As: Resultant.

e. Check Animate.

f. Select Animation Options.

a

b

f

c

View Subcases

d

e



33/44

WS17-33



IfView Subcases icon is used to

select subcases, the followingsteps are to be followed:

a. Click on View Subcases

then Select Subcases.

b. Filter Method: GlobalVariable.

c. Variable: Time: Min:0.

d. Values: Above: Value:0.

e. Select Filter. This will fill outthe bottom of the dialogue.

f. Click on Apply.

g. Click on Close.

h. UnderSelect Result Case(s)

theres only one line for all

transient results, 3001 of

3001 subcases.

i. Select Displacement,Translational underSelect

Deformation Result.

j. Show As: Resultant.

k. Check Animate.

l. Select Animation Options.

b

cd

e

f

h

i

j

k

l



34/44

WS17-34



Continue to view transient

deformation results.

a. Animation Method: GlobalVariable.

b. Select Time underSelectGlobal Variable.

c. Set End Value to 3.0.

d. Select 3D underAnimationGraphics.

e. Number of Frames: 24.

f. Click on Apply.

a

b

d

e

f

c

Step 12. Create an XY Plot of Displacement Versus Time


35/44

WS17-35



Create XY plot of displacement

versus time.

a. Results: Create / Graph /Y vs X.

b. Select All result cases manuallyunderSelect Result Cases(s) by

using the Shift key .

c. Select Displacements,Translational underSelect YResult.

d. Quantity:Y Component.

e. X: Global Variable.

f. Variable: Time.

g. Select on Target Entities icon.

a

b

c

d

efg


36/44

Step 12. Create an XY Plot of Displacement Versus Time (Cont.)


37/44

WS17-37



View resulting plot.

a. The plot should look like thefollowing.

The XY plot is created for one

displacement, Node 44 Y-component.

Notice that the displacement follows the

applied force.

Step 12. Create an XY Plot of Displacement Versus Time (Cont.)


38/44

WS17-38



Create another XY plot

a. Add another XY plot by

selecting the node shown inthe figure.

The XY plot is created for two displacements.


39/44

Step 13. Customize the Appearance of the XY Plot (Cont.)


40/44

WS17-40



Continue to customize the

appearance of the XY plot.

a. XY Plot: Create / Title.

b. Title: Displ vs. Time .

c. Change X Alignment to

Percent(%) and setX Location (%): 39.

d. Y Location (%): 14.

e. Font Size: 18.

f. Click on Apply.

g. Modify / Legend.

h. Title: ND.

i. Click on Apply.

a

b

c

d

e

f

g

h

i



41/44

WS17-41



Continue to customize the appearance of

the XY plot

a. Modify / Axis.

b. Active Axis: X.

c. Scale

d. Assignment Method: Range.

e. Enter0.0, 3.0 forLower and UpperValues.

f. Enter10 forNumber of Primary TickMarks.

g. Click on Apply.h. Click on Cancel.

i. Tick Marks

j. Check both Primary and SecondaryforDisplay.

k. Click on Apply.

l. Click on Cancel.m. Grid Lines

n. Check both Primary and SecondaryforDisplay.

o. Click on Apply.

p. Click on Cancel.

a

b

c

d

e

f

g h

i

j

k l

m



42/44

WS17-42



Continue to customize the

appearance of the XY plot.

a. Active Axis:Y.

b. Title

c. Axis Title: Displ, Trans.

d. Click on Apply.

e. Click on Cancel.

f. Tick Marksg. Check both Primary and

Secondary forDisplay.

h. Click on Apply.

i. Click on Cancel.

j. Grid Lines

k. Check both Primary andSecondary forDisplay.

l. Click on Apply.

m. Click on Cancel.

a

b

c

d e

f



43/44

WS17-43



This ends this exercise.Exit MSC.Patran

a. File / Close.


44/44

WS17-44



16 boxbm transient pat301

Documents