Workshop 5-1 NAS101 Workshops Copyright 2001 MSC.Software Corporation WORKSHOP 5 Stiffened Plate Subjected to Pressure Load

Workshop 5-1NAS101 WorkshopsCopyright 2001 MSC.Software Corporation

WORKSHOP 5

Stiffened Plate Subjected to Pressure Load


Workshop 5

1. Stiffened Plate Model

2. GOAL: model a stiffened panel using plate elements for the panel and BEAM elements for the stiffener


Workshop 5 (cont.)

1. Stiffened Plate Model2. We will model a plate which is .1

inches thick, 20.0 inches long, and 10.0 inches wide. The stiffener is shown below, along with the plate dimensions and loading

3. The model has pinned supports at the corners


Workshop 5 (cont.)

1. Stiffened Plate Model2. Material properties:

a. E = 10.3E+6 psib. Poissons Ratio = .3c. Density = .101 lb/in3 (weight

density)3. The stiffener will be modeled using a

BEAM with a PBEAML to define the cross-section

4. The GRID points will lie at the mid-plane of the plate, so the BEAM must be offset from the GRID points by 1.05 (half the BEAM height pus half the plate thickness)


Workshop 5 (cont.)

1. Stiffened Plate Model2. The Model


Workshop 5 (cont.)

1. Stiffened Plate Model2. PBEAML Entry

PBEAML,2,1,,I,2.,1.,1.,.1,.1,.1

1. Sample CBEAM

CBEAM 21 2 31 32 0. 0. 1. 0. 0. 1.05 0. 0. 1.05


Workshop 5 (cont.)

1. Stiffened Plate Model - Pressure Load Definition2. Pressure loads on plate and shell elements are defined using PLOAD2 or PLOAD4 entries

3. SID = Static Loading Set ID4. EIDi = Element ID5. P = Pressure (applied in element coordinate system)

PLOAD2,1,-.5,1,THRU,20


Workshop 5 (cont.)


Suggested Exercise Steps:1. Create a finite element model of the plate made of

CQUAD4 elements.The stiffener is made of BEAM element.

2. Define material properties. (MAT1)3. Define element properties and sectional properties

using the BEAM library. Apply loads and boundary conditions to the model.

4. Submit the model to MSC.Nastran for analysis.5. Post-Process results using MSC.Patran.


Create the first surface

a. Create / Surface / XYZ.

b. Enter <20 5 0> for the Vector Coordinate List.

c. Use [0 0 0] as the Origin Coordinate List.

d. Click Apply.

Step 1. Create Geometry: Create/Surface/XYZ


Create the second surface

a. Create / Surface / XYZ.

b. Enter <20 5 0> for the Vector Coordinate List.

c. Select the point option on the right for the origin Coordinate List and pick point 2 as the origin.

d. Click Apply.

Step 1A. Create Geometry: Create/Surface/XYZ


Create mesh seeds that will be used to guide the mesh.

a. Create / Mesh Seed / Uniform.

b. For the Number of Elements, input 5.

c. Select Surface 1.2 as the Curve List.

d. Click Apply.

Step 2. Finite Element: Create /Mesh Seed/Uniform

Surface 1.2

Surface 1.1

Surface 2.1


Repeat the previous procedures to create 2 more sets of mesh seeds

Create / Mesh Seed / Uniform.

a. Input 2 use the Number of Elements.

b. Select Surface 1.1 and Surface 2.1 as the Curve List.

c. Click Apply.

Step 2A. Finite Element: Create /Mesh Seed/Uniform


Step 2B. Finite Element: Create /Mesh/Surface

Create surface mesh based on the mesh seeds assigned in the previous steps.

a. Create / Mesh / Surface.b. Select Quad as the Elem

Shape.c. Select IsoMesh as the Mesher.d. Enter Surface 1 2 for Surface

List.e. Click Apply.


Step 2C. Finite Element: Create /Mesh/Curve

Create surface mesh based on the mesh seeds assigned in the previous steps.

a. Create / Mesh / Curve.b. Select Bar2 as the Element

Shape.c. Enter the curves by selecting

the curves off the screen Surface 1.4 1.2 2.2 for Curve List.

d. Click Apply.


Step 2D. Finite Element: Equivalence /All/Tolerance Cube

Merge all the coincident nodes by using Equivalence function.

a. Equivalence / All / Tolerance Cube.

b. Click Apply.

a

b


Step 3. Material: Create /Isotropic/ Manual Input

Create the material aluminum.a. Create / Isotropic / Manual

Input.b. Type in alum for the Material

Name.c. Click on the Input Properties

button to bring up the Input Option window.

d. Enter 10.3E6 for the Elastic Modulus , and 0.3 for Poisson Ratio,and 0.101 for the density.

e. Click OK to return to the main material menu.

f. Click Apply.


Step 4. Element Properties: Create /2D/ Shell

Create the element properties.a. Create / 2D / Shell.b. Enter plate as the Property

Set Name.c. Click on the Input Properties

button.d. Click on the alum in the

Material field on the bottom section of the Input Properties window.

e. Enter 0.1 as the thickness for the plate.

f. Click OK.g. Select element 1:20 for the

Application Region.(pick the element icon)

h. Click Add.i. Click Apply.


Step 4A. Element Properties: Create /1D/ Beam

Create the element properties.a. Create / 1D / Beam.b. Enter beam as the Property Set

Name.c. Toggle the button from General

section to Tapered Section. General section in NASTRAN means the CBAR element whereas Tapered section means CBEAM element.

d. Click on the Input Properties button.

e. Click on the alum in the Material field on the bottom section of the Input Properties window.

f. Under the section name we would select ibeam. On the next slide I will show you how to use the beam library.

g. Click OK.h. Select element 21:35 for the

Application Region.(pick the element icon)

i. Click Add.j. Click Apply.


Step 4B. Beam library: Create /Standard Shape/NASTRAN standard

Create the beam cross sectional using IBEAM .

a. Enter ibeam as the Section Set Name.

b. Click on Ibeam button.c. Input H,W1,W2,t,t1,t2 asd. 2,1,1,0.1,0.1,0.1e. Click on Calculate/Display,

then you will see the following section diagram on the next page

f. Click OK


STEP 4C: Display the Beam cross sectional area


Step 5. Loads/BCs: Create/ Displacement/Nodal

Create the boundary condition for the model.

a. Create / Displacement / Nodal.

b. Enter translations as the New Set Name.

c. Click on the Input Data.d. Enter <0 0 0> for the

Translation field.e. Click OK.f. Click on Select

Application Region.g. Select FEM as the

geometry filter..h. Select Node 1,6,31,36 for

the Application Region.These are the four corner nodes in the model.

i. Click Add.j. Click OK.k. Click Apply.


Step 5A.(cont.) Loads/BCs: Create Boundary Conditions

After you have completed previous steps,then you see the constraints on the model as shown below:


Step 6. Loads/BCs: Create/Pressure /Element Uniform

Apply pressure load to the model.a. Create / Pressure / Element

Uniformb. Enter pressure as the New

Set Name.c. Click on the Input Data

button.d. Enter 0.5 in the Top Surf

Pressure box.e. Click OK.f. Click on Select Application

Region button.g. Select FEM as the

Geometry Filter.h. Select Element 1:20 for the

Application Region.i. Click Add, and OK.j. Click Apply.


Step 6(cont.) Loads/BCs: Create Pressure Load

You can see the pressure load value of 0.5 is imposed on top of the plate.


Step 7. Analysis: Analyze/ Entire Model/Full Run

Submit the model for analysis.a. Analyze / Entire Model / Full

Run.b. Click on the Solution Type.c. Select LINEAR STATIC as the

Solution Type.d. Click OK.e. Click Apply.


Step 8. Analysis: Attach XDB/ Result Entities/ Local

Attach the XDB result file.a. Attach XDB / Result Entities /

Local.b. Click on Select Result File.c. Select the file called w5.xdbd. Click OK.e. Click Apply.


Step 8 (cont.) Results: Create/Quick Plot

Create a Quick Plot of the results.a. Create / Quick Plot.b. Select SC1 result case.c. Select Displacement,

Translational for the Deformation Result.

d. Click Apply.

Note: Maximum Deformation is 6.64E-2.

These information appear at the lower right hand corner of the plot.


Step 9 (cont.) Fringe Results: Create/Quick Plot

Create a Quick Plot of the results.a. Create / Quick Plot.b. Select SC1 result case.c. Select Stress Tensor for the

Fringe Resultd. Select Displacement,

Translational for the Deformation Result.

e. Click Apply.

Note: Maximum Stress value is 2.92E+3

Documents

Workshop 5-1 NAS101 Workshops Copyright 2001 MSC.Software Corporation WORKSHOP 5 Stiffened Plate Subjected to Pressure Load