Beam model with a not typical beam cross section

Introduction:


In this exercise the modeling with a beam element will be introduced. The method of modeling, meshing and a model analyzing will be shown. I am going to present, how to build a beam model with beam cross section which is not define be in the Femap software. In the exercise a frame model will be prepared. The theoretical model is presented below:

1. Model details

Dimensions:

A = 0.1   [m]
B = 0.03 [m]
C = 0.01 [m]
D = 1      [m]
E = 1,5   [m]
F = 0,2   [m]

Materials data:
For the model steel St36 is used.

E= 2.06e11 [N/m2]
υ= 0.3
ρ= 7.85e3 [kg/m3]

2. Geometry

To create geometry please follow the steps, most of the steps are the same as in the previous exercise so will be only decribed without a pictures:

In first step I am going to show how to prepare triangle shape:

- Creating a point:

Geometry => Point (fill in the points co ordinations in the window)

First point: 0,0,0 => OK
Second point: 0.1,0,0 => OK
Third point: 0.05,0.1,0 => OK

In the result , we receive 3 points which should be connected by the lines . The lines create a border of the surface. To create surface please follow the steps below.
Geometry => Surface=> Edge curves => (in window check 3-sides) => choose 3 edges => OK
Now do the same steps with the second profile.

-Creating a construction:
I am going to prepare a first quadratic section and copy it 3 times:
Create a points:
Geometry => curve-line => points
P1: 0,0,0
P2: 0.2,0,0
P3: 1.2;0,0
P4: 1.2,1,0
P5: 0.2,1,0

Now create lines between the points:


-Coping the edges:

Geometry => Copy => Curve... => select lines from quadratic section => in repetition window insert 4 and OK=> OK


3. Properties

To create properties please follow the steps:

-Creating materials:
Please create a material like on the previous exercises.

-Creating properties
Model=>Property => select beam as a element type => shape and follow the steps below

Now please do the same with the second profile.


4. Boundary conditions

-Creating constraints:

Model=> constraints => Create/ Manage Set => follow the instruction from exercise 1
Please choose the points which are shown on the picture below.

5. Meshing


To mesh geometry follow the steps below.

Mesh=>Mesh control=>default size=> fill 0.3 in size gap

Mesh=>Mesh control => Attributes along curve => select all => follow the steps from previous exercise

Mesh => Geometry => Curve => select all => OK

To see cross section use the button shown below:

Now we have completely meshed geometry with constraints and loads. Which should looks like on the picture below:

Frame model

Exercise:




Introduction:

In this exercise the modeling with a beam element will be introduced. The method of modeling, meshing and a model analyzing will be shown. I am going to present, how to a whole geometry and model analyzing in the Femap software environment prepare. In the exercise a frame model will be prepared. The theoretical model is presented below:

1. Model details

Dimensions:

a= 10 [m]
b= 5  [m]
c= 5  [m]
h= 5  [m]

Materials data:

For the model steel St36 is used.

E= 2.06e-11 [N/m2]
υ= 0.3
ρ= 7.85e3 [kg/m3]

Load:
Force = 1000 N

2. Geometry

To create geometry please follow the steps, most of the steps are the same as in the previous exercise so will be only decribed without pictures:

- Creating a point:
Geometry => Point (fill in the points co ordinations in the window)

First point: 0,0,0 => OK
Second point: 10,0,0 => OK
Third point: 5,5,0 => OK

In the result , we receive 3 points which give corners of triangle.

-Creating a line:

Connect the points in the way that give a triangle shape.
Geometry => curve-line => points 

-Coping the edges:
Geometry => Copy => Curve... => select all => in repetition window insert 3 and OK=> fill in like on the window => OK

In the result you have a model like on the picture below:

3. Properties

To create properties please follow the steps:

-Creating materials:

Model => Material

Please fill the STIFFNESS block as is shown on the picture below (that is minimum).

-Creating properties

Model => Property

To create beam property please follow the steps from the first exercise and pictures below.

Click Elem/Prop Type to choose the beam element.

Click OK and choose a shape button.

Now the beam property is created.


4. Loads and boundary conditions

-Creating loads:

Model=> Load => Create/ Manage Set => follow the numbers from the exercise 1 or try to do yourself

Model=> Load => on point(s) => choose a point (like on the picture below)

-Creating constraints:

Model=> constraints => Create/ Manage Set => follow the instruction from exercise 1
Please choose the points which are shown on the picture below.

In the result we get the model as on the picture below.

5. Meshing

To mesh geometry follow the steps below.

Mesh=>Mesh control=>default size=> fill 1 in size gap
Mesh=>Mesh control => Attributes along curve => select all => follow the steps from previous exercise

Mesh => Geometry => Curve => select all => OK

Now we have completely meshed geometry with constraints and loads. Which should looks like on the picture below:

6. Analyzing

Prepare the analysis set.

7. Results


To receive analysis results as a graphic figure follow the steps below.

F5=>Beam Diagram=> chose contour type => OK => OK

In contour choose "3167..Beam EndB Min Comb Stress"
To make a stress results more clear please push F6 button and open view options.

Finally you receive the following graph:

Results with Combined Stresses

Combine stress results with deflections

Extra exercise for individual performance:

Prepare and analyze model shown on the picture below:

Beam model tutorial

Short theory:


Beam element is a very versatile line-element; in general, it has six degrees of freedom at
each node, which include, translations and rotations along the x, y, and z directions, respectively. Figure 4.1 shows the positive directions of these displacements.

Beam element is employed to simulate a slender structure that has an uniform cross
section. The element is unsuitable for structures that have complex geometry, holes, and
points of stress concentration.
The stiffness constant of a beam element is derived by combining the stiffness constants
of a beam under pure bending, a truss element, and a torsion bar. Thus, a beam element
can represent a beam in bending, a truss element, and a torsion bar. In FEA it’s a
common practice to use beam elements to represent all or any of these three load types.
We will derive the element stiffness equation for a beam element by first deriving the
stiffness equation of a beam in bending, and then superimposing the stiffness of a truss
and a torsion bar element.

Exercise:

Introduction:

In this exercise the modeling with a beam element will be introduced. The method of modeling, meshing and a model analyzing will be shown. I am going to present, how to a whole geometry and model analyzing in the Femap software environment prepare. For the beginning exercise simple beam model will be used. The beam supported on the two ends will be prepared. All details are shown on the picture below:

1. Model details

Dimensions:
a= 150 [mm]
b= 100 [mm]
c= 5[mm]
h= 10 [mm]

Materials data:
For the model steel St36 is used.
E= 2.05e-5 [N/mm2]
υ= 0.3
ρ= 7.85e-6 [kg/mm3]

Load:
Force = 1000 N

2. Geometry

To create geometry please follow the steps:

Creating a point:
Geometry => Point (fill in the points co ordinations in the window)

First point: 0,0,0 => OK
Second point: 150,0,0 => OK
Third point: 250,0,0 => OK

In the result , we receive 3 points (yellow crosses).

Creating a line:
Geometry => curve-line => points (points can be chosen by clicking on them or by filling the empty places in the window).

First line: first click on the left point and next on the middle point.
Second line: first click on the middle point and next on the right point.

In the result you have two lines like on the picture below:

3. Properties

To create properties please follow the steps:

Creating materials:
Model => Material
Please fill the STIFFNESS block as is shown on the picture below (that is minimum).

Creating properties
Model => Property
To create beam property please follow the number on the pictures.

Now the beam property is created.

4. Loads and boundary conditions

Creating loads:
Model=> Load => Create/ Manage Set => follow the numbers

Model=> Load => on point(s) => follow the numbers

Creating constraints:
Model=> constraints => Create/ Manage Set => follow the numbers

Please chose the point on the left side of the beam.

This point is fixed.

For the other point the constraint will be prepared in the same way

The second end of the beam is blocked in two directions so the TX and TY displacement must be blocked.

In the result we get the model as on the picture below.

5. Meshing

To mesh geometry follow the steps below.
Mesh=>Mesh control=>default size=> fill 10 in size gap

Mesh=>Mesh control => Attributes along curve => select all =>

Mesh => Geometry => Curve => select all => OK
Now we have completely meshed geometry with constraints and loads.

6. Analyzing

To analyze model must be create analyze set. It can be done by following way.
Model=> Analysis

7. Results

To receive analysis results as a graphic figure follow the steps below.
F5=>Beam Diagram=> chose contour type => OK => OK

Finally you receive the following graph:

End of the beam model tutorial and good luck !