Dynamic Response Tutorial Ver 611

8/13/2019 Dynamic Response Tutorial Ver 611

1/152012 Hormoz Zareh & Jenna Bell 1 Portland State University, Mechanical Engineering

Abaqus/CAE (ver. 6.11)Dynamic Response Tutorial

Problem Description

The two-dimensional bridge structure, which

consists of steel T-sections, has pinnedsupports at its lower corners, and subjected to

the following time varying load applied at the

lower mid-span point.

0

0.2

0.4

0.6

0.8

1

1.2

0 0.05 0.1 0.15 0.2 0.25

LoadAmplitude

Time [s]



Analysis Steps1. Start Abaqus and choose to create a new model database2. In the model tree double click on the Parts node (or right click on parts and select Create)

3. In the Create Part dialog box (shown above)a. name the partb. Select 2D Planarc. Select Deformabled. Select Wiree. Set approximate size = 20f. Click Continue

4. Create the geometry shown below (not discussed here)



5.Double click on the Materials node in the model treea. Name the new material and give it a descriptionb. Click on the Mechanical tabElasticityElasticc. Define Youngs Modulus (210e9 Pa) and Poissons

Ratio (0.25) (SI units)

d. Click on the General tabDensitye. Density = 7800 (kg)f. Click OK



6. Double click on the Profiles node in the model treea. Name the profile and select T for the shapeb. Note that the T shape is one of several predefined

cross-sections

c. Click Continued. Enter the values for the profile shown belowe. Click OK

7. Double click on the Sections node in the model treea. Name the section BeamPropertiesb. Select Beam for both the category and the typec. Click Continued. Leave the section integration set to During Analysise. Select the profile created above (T-Section)f. Select the material created above (Steel)g. Click OK


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012 Hormoz Zar

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15.Double click on the BCs node in the model treea. Name the boundary conditioned Pinned and select

Displacement/Rotation for the type

b. Click Continuec. Select the lower-left and lower-right corners of the geometry

and press Done in the prompt area

d. Check the U1 and U2 displacements.e. Click OK



16.Double click on the Steps node in the model treea. Name the step, set the procedure to Linear perturbation, and

select Modal dynamics

b. Click Continuec. On the basic tab, set the time period to 0.5 and the time increment

to 0.005 (total of 100 increments)

d. On the damping tab, apply a critical damping fraction of 0.05 to all50 mode

17. In the model tree double click on Amplitudesa. Select Tabular and name the amplitudeb. Specify a smoothing factor of 0.25c. Enter the time and amplitudes shown below



18.Double click on the Loads node in the model treec. Select Concentrated force and click Continued. Select the point in the middle of the lower membere. Set CF2 to -100000f. Choose the amplitude created above and click OK



19.Double click on the History output requests node inthe model tree

g. Name the history output, select the modaldynamics step, and click Continue

h. Set the domain to Set and select the setcreated above

i. For the frequency choose to output every 1increments

j. For the output select the U2 displacementk. Click OK

20. In the model tree double click on Mesh for the Bridge part, and in thetoolbox area click on the Assign Element Type icon

a. Select Standard for element typeb. Select Linear for geometric orderc. Select Beam for familyd. Note that the name of the element (B21) and its description are

given below the element controls

e. Click OK



21. In the toolbox area click on the Seed Edges icon.a. Select the entire geometry and click Done in

the prompt area

b. Select By Number for Method.c. Set Number of elements to 20. Click OK

22. In the toolbox area click on the Mesh Part icona. Click Yes in the prompt area

23. In the model tree double click on the Job nodea. Name the jobb. Click Continuec. Give the job a descriptiond. Click OK



24. In the model tree right click on the job just created (Linear_dynamics) and select Submita. While Abaqus is solving the problem right click on the job submitted (Linear_dynamics), and select

Monitor

b. In the Monitor window check that there are no errors or warningsi. If there are errors, investigate the cause(s) before resolving

ii. If there are warnings, determine if the warnings are relevant, some warnings can be safelyignored

25. In the model tree right click on the submitted and successfully completed job , and select Results


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012 Hormoz Zare

26.Displaa.b.c.

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29.Click on the arrows on the context bar to change the time step being displayeda. Click on the three squares to bring up the frame selector slider bar

30.Click on the Create X-Y Data icona. Select ODB history outputb. Scroll to find Spatial displacement: U2 at Node 3 in NSET MIDSPANc. Click Plot

Similar plots can be obtained for other parameters of interest. Also, the Data File tab from Job monitor

can be viewed to determine important parameters such as total mass of the system as well as effective

mass for individual degrees of freedom.

Dynamic Response Tutorial Ver 611

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Transcript of Dynamic Response Tutorial Ver 611