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MIDTERM #1

Terms in this set (31)

What kind of constraints did we put on the cantilever plate FEM in workshop 1?
a)Both translations and rotations
b)Translations only
c)None
d)Rotations only
a)Both translations and rotations
The FEM calculations using Nastran -- computes which of the following first?
a)None of the above
b)Displacement
c)Stress
d)Strain
b)Displacement
S/A: Why do we put the "%1" in the Start Block on Properties of the Patran icon?
The %1 will cause all files associated with that file to populate in the folder it is placed in and not some temporary folder in an unknown location.
The network of elements and nodes that discretize a region of geometry is called a _______
I don't know
Grouping
a. Union
b. System
c. Mesh
d. Model
c. Mesh
After we create materials, what is generally the next step in creating a FEM?
a. Create elements
b. Run the Nastran analysis
c. Check Load Cases
d. Assign Properties to the elements
e. Run the Patran analysis
d. Assign Properties to the elements
For 1-D modeling in Patran, it is always best to apply Loads and BCs to FEM "Nodes" instead of "Geometric Points".
a. True
b. False
a. True
Troubleshooting steps for Patran FEM include which of these? (select multiple if they apply)
a. Elements --- Equivalence/All/Tolerance Cube
b. Using the "L" label icon to view numbering of items
c. None of the Options
d. Elements --- Verify/Element/Boundaries
e. Loads/BCs ---- Plot Markers
f. All of the Options
f. All of the Options
The terms "Nodes" and "Grid Points" refer to the same thing in FEM.
a. True
b. False
a. True
The assembly of all the elemental stiffness matrices is sometimes called the "global stiffness matrix".
a. True
b. False
a. True
What are the actual numbers in an "elemental stiffness matrix" for a hand FEA of bar element (1-D), given these terms:
If L1 = 5, A1 = 3, E1 = 5000
(Hint: This is the number that you calculate to then insert into the matrix.)
a. 375
b. 1500
c. 3000
d. 60000
c. 3000
You see the message "unable to access results", after you have successfully performed an analysis on an earlier date. What step(s) do you do next ?
a. None of the options
b. Reattach the results
c. Delete the results and reattach
d. Start over
c. Delete the results and reattach
How can you tell if you have duplicate nodes ?
a. All of the options
b. Verify
c. Equivalence
d. Label nodes
e. None of the options
a. All of the options
A group labeled "default_group" is created automatically when a database is created.
a. True
b. False
a. True
Von Mises stresses are a combination of _______ and _______.
(Select all that apply)

a. None of the options
b. Concentrated stresses
c. Shearing stresses
d. All of the options
e. Normal stresses
f. Strains
c. Shearing stresses
e. Normal stresses
The actual numbers in an "elemental stiffness matrix" for a hand FEA of bar element (1-D), given these terms:
If L1 = 10, A1 = 4, E1 = 500
a. 200
b. 1250
c. None of the options
d. 2000
a. 200
To what do you typically compare your stress values from a FEA ?
a. Yield stress
b. I don't know
c. None of the Options
d. Ultimate stress
e. Shear stress
a. Yield stress
Margin of Safety easier to use than Factor of Safety.
a. True
b. False
a. True
The finite element method that we are using is called the ______ or ________ method.
a. Both Options
b. Stiffness
c. Neither Options
d. Displacement
a. Both Options
Pressure can be applied to 2-D elements in what ways ?
(Select all that apply)
a. None of the Options
b. Bottom surface
c. Top surface
d. Edges
b. Bottom surface
c. Top surface
d. Edges
A bar element, also known as a truss bar element or axial element, can be considered the simplest form of structural finite element.
a. True
b. False
a. True
Triangular, rectangular, tetrahedral, quadrilateral, and hexagonal shapes of elements are commonly used in FEA
a. True
b. False
a. True
1) Besides the Force matrix and displacement matrix, what other matrix is used in FEA calculations?
a. Stiff variable matrix
b. Time matrix
c. Global stiffness matrix
d. Nodal pressure matrix
c. Global stiffness matrix
What is a numerical approach that is well suited for digital computers?
Finite Element Analysis
To run a Normal Modes Analysis, you must enter a Force or Pressure Load on the model.
a. True
b. False
b. False
The Weight -Mass conversion for a normal modes analysis --- is what ?
a. 0.000259
b. 0.0259
c. None of these
d. 0.00259
d. 0.00259
For 2-D elements, why is it important to know where the positive Z axis is located in the elemental coordinate system?
a. Both of these
b. To ensure model integrity
c. Neither of these
d. To apply pressure loading
a. Both of these
Why do we run a normal modes analysis?
a. Both of these
b. To compute the natural frequencies for a structure
c. To determine the modes for a structure
d. Neither of these
a. Both of these
Why would we want to create a separate coordinate system ?
a. To add a pressure distribution
b. To define a displacement reference
c. All of these
d. To add a field
e. None of these
c. All of these
Which element is considered the simplest form of structural finite element?
a. A truss bar finite element.
b. A complex finite element.
c. A beam finite element.
d. A frame finite element.
a. A truss bar finite element. as known as axial element or bar element, truss bar element is known as the simplest form of structural finite element.
What are other names for a bar element?
a. Beam element
b. Truss element
c. Axial element
d. Geometry
a. truss element & c. axial element
In order to super impose two element stiffness matrices, k1 and k2, the matrices are multiplied together, and then the resulting matrix A is multiplied by an identity matrix of the same size.
a. True
b. False
False
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