Tutorial Software| jogjatutorial

Monday, July 02, 2007

Dome Cylindrical Structure

Click the File menu > New Model command to display the New Model form.
Click the drop-down box to set the units to ..
Click on the Shells button to display the Shells form. In that form:

Select Cylinder in the Shell Type drop-down list.
Accept the default Num of Divisions, Angular, 16.
Type 8 in the Number of Divisions, Z edit box.
Type 20 in the Cylinder Height edit box.
Type 10 in the Radius edit box.
Click the OK button.

Click in the “X” in the upper right-hand corner of the X-Y Plane @ Z=0 window to close it.
Click the Set Display Options button (or the View menu > Set Display Options command) to display the Display Options for Active Window form. In that form:

Check the Fill Objects box.
Click the OK button.

Click the Edit menu > Add To Model From Template command to display the New Model form. In that form click on the Shells button to display the Shells form. In that form:

Select Spherical Dome in the Shell Type drop-down list.
Accept the default Num Divisions, Angular, 16.
Type 4 in the Number of Divisions, Z edit box.
Type 10 in the Radius, R edit box.
Accept the default Roll Down Angle,T, 90.
Uncheck the Restraints check box if it is not already unchecked.
Click the Locate Origin button to display the Coordinate System form.

Note: The Coordinate System form is being used to define a location of the origin of a new coordinate system and its rotation with respect to the global coordinate system. The origin point of the template will be inserted at the origin of this newly defined coordinate system.

In the Coordinate System form:
- Select the 3D option.
- In the Translations area, type 20 in the Z edit box.
- Click the OK buttons on the Coordinate System and Shell forms to exit all forms.

Press the F7 key on the keyboard to toggle the grid lines off.

Wall Resisting Hydrostatic Pressure

Hydrostatic Loading
Joint Patterns

Click the File menu > New Model command to display the New Model form.
Click the drop-down box to set the units to .
Click on the Wall template button to display the Shear Wall form. In that form:

Type 30 in the Number of Divisions, X edit box.
Type 15 in the Number of Divisions, Z edit box.
Type 1 in the Division Space, X edit box.
Type 1 in the Division Space, Z edit box.
Click the OK button.

Click the “X” in the top right-hand corner of the 3-D View window to close it.
Click the drop-down box in the status bar to change the units to .
Click the Define menu > Materials command to display the Define Materials form. Highlight the CONC material and click the Modify/Show Material button to display the Material Property Data form. In that form:

Verify that the Modulus of Elasticity is 3600 and Poisson’s ratio is 0.2.
Click the OK buttons on the Material Property Data and Define Materials forms to close the forms.

Click the drop-down box in the status bar to change the units to .
Select all of the support joints at the bottom of the wall by “windowing.”
Click the Assign menu > Joint > Restraints command to display the Joint Restraints form. In that form:

Click the fixed base fast restraint button to set all degrees of freedom (U1, U2, U3, R1, R2 and R3) as restrained.
Click the OK button.

Click the Define menu > Joint Patterns command to display the Define Pattern Names form. In that form:

Type HYDRO in the edit box in the Patterns area.
Click the Add New Pattern Name button.
Click the OK button.

Click the Select All button on the side tool bar.
Click the Assign menu > Joint Patterns command to display the Pattern Data form. In that form:

Select HYDRO from the Pattern Name drop-down list.

Note: Press the F1 key on the keyboard for context sensitive help on the form illustrating the definition of the Constants. When finished reading the help, click the “X” in the top right-hand corner of the Help window to close it.

Type -1 in the Constant C edit box.
Type 15 in the Constant D edit box.
Click the OK button.

Click the Select All button .
Click the Assign menu > Area Loads > Surface Pressure (All) command to display the Area Surface Pressure Load form. In that form:

Select the By Joint Pattern option.
Select HYDRO from the Pattern drop-down list.
Type .0624 in the Multiplier edit box.
Click the OK button.

Click the Show Undeformed Shape button to remove the displayed joint force assignments.
Click the Run Analysis button to display the Set Analysis Cases to Run form. In that form:

Highlight (select) MODAL in the Case Name list and click the Run/Do Not Run Case button.
Verify that the DEAD analysis case is set to Run in the Action list.
Click the Run Now button to run the analysis.

When the analysis is complete check the messages in the SAP Analysis Monitor window (there should be no warnings or errors) and then click the OK button to close the window.
Right click on the center joint at the top of the wall and note the Y-direction displacement.
Click the Lock/Unlock Model button and click the resulting OK button to unlock the model.
Select the joints along the sides of the model by “windowing” each side separately.
Click the Assign menu > Joint > Restraints command to display the Joint Restraints form. In that form:

Click the fixed base fast restraint button to set all degrees of freedom (U1, U2, U3, R1, R2 and R3) as restrained.
Click the OK button.

Click the Run Analysis button to display the Set Analysis Cases to Run form. In that form, click the Run Now button to run the analysis.
When the analysis is complete check the messages in the SAP Analysis Monitor window (there should be no warnings or errors) and then click the OK button to close the window.
Right click on the center joint at the top of the wall and note the Y-direction displacement

Barrel Vaulted

Add To Model From Template
Response Combinations
New Model From Template

Click the File menu > New Model command to display the New Model form.
Click the drop-down box to the units to .
Click on the Shells button to display the Shells form. In that form:

Select Barrel Shell in the Shell Type drop-down list.
Accept the default Number of Divisions, Axial, 8.
Accept the default Number of Divisions, Angular, 8.
Type 40 in the Length, L edit box.
Type 35 in the Roll Down Angle, T edit box.
Type 20 in the Radius, T edit box.
Uncheck the Restraints check box.
Click the OK button.

Click in the 3-D View window to make sure it is active. The window is highlighted when it is active.
Click the Select All button on the side toolbar to select the entire structure.
Click the Edit menu > Move command to display the Move form. In that form:

Type 10 in the Delta Z edit box.
Click the OK button.

Click the Edit menu > Add To Model From Template command to display the New Model form. In that form click on the Shells button to display the Shells form. In that form:

Select Barrel Shell in the Shell Type drop-down list.
Accept the default Number of Divisions, Axial, 8.
Accept the default Number of Divisions, Angular, 8.
Type 40 in the Length, L edit box.
Type 35 in the Roll Down Angle, T edit box.
Type 30 in the Radius, R edit box.
Uncheck the Restraints check box if it is not already unchecked.
Click the Locate Origin button to display the Coordinate System form. In that form:
- Select the 3D option.
- Type 25 in the Z edit box in the Translations area.
- Click the OK buttons on the Coordinate System and Shells forms to exit all forms.

Click in the Y-Z Plane @ X=-20 window to make sure it is active.
Verify that the drop-down list for the Coordinate System shows on the Status Bar.
Click the Set Display Options button (or the View menu > Set Display Options command) to display the Display Options for Active Window form. In that form:

Check the Labels box in the Joints area.
Click the OK button.

Right click on joint 82 in the Y-Z Plane @ X=-20 window. The Point Information form is displayed.
Highlight the Y-coordinate (-17.2073) and press the Ctrl and the C keys on the keyboard at the same time to copy the value to the clipboard.
Click the Cancel button to close the Point Information form.
Click the Edit menu > Add To Model From Template command to display the New Model form. In that form click on the Wall button to display the Shear Wall form. In that form:

Type 8 in the Number of Divisions, X edit box.
Type 4 in the Number of Divisions, Z edit box.
Type 5 in the Division Width, X edit box.
Type 2.5 in the Division Width, Z edit box.
Uncheck the Restraints check box if it is not already unchecked.
Click the Edit Grid button to display the Define Grid Data form. In that form:
- Click the Locate System Origin button to display the Coordinate System form. In that form:
  - Select the 3D option.
  - Highlight the Y edit box in the Translations area and press the Ctrl and the V keys on the keyboard at the same time to paste the -17.2073 value from the clipboard.
  - Type 15 in the Z edit box in the Translations area.
  - Click the OK buttons on the Coordinate System, Define Grid Data and Shear Wall forms to exit all forms.

Verify that the drop-down list for the Coordinate System shows on the Status Bar.
Right click on joint 1 in the Y-Z Plane @ X=-20 window. The Point Information form is displayed.
Highlight the Y-coordinate (-11.4715) and press the Ctrl and the C keys on the keyboard at the same time to copy the value to the clipboard.
Click the Cancel button to close the Point Information form.
Click the Edit menu > Add To Model From Template command to display the New Model form. In that form click on the Wall button to display the Shear Wall form. In that form:

Type 8 in the Number of Divisions, X edit box.
Type 4 in the Number of Divisions, Z edit box.
Type 5 in the Division Width, X edit box.
Type 2.5 in the Division Width, Z edit box.
Uncheck the Restraints check box if it is not already unchecked.
Check the Use Custom Grid Spacing and Locate Origin check boxes.
Click the Edit Grid button to display the Define Grid Data form. In that form:
- Click the Locate System Origin button to display the Coordinate System form. In that form:
  - Select the 3D option.
  - Highlight the Y edit box in the Translations area and press the Ctrl and the V keys on the keyboard at the same time to paste the -11.4715 value from the clipboard.
  - Click the OK buttons on the Coordinate System, Define Grid Data and Shear Wall forms to exit all forms.

Verify that the drop-down list for the Coordinate System shows on the Status Bar.
Click in the Y-Z Plane @ X=-20 window to make sure it is active.
Click the View menu > Set 2D View command to display the Set 2D View form. In that form:

Select the X-Z plane option.
Type -11.4715 in the Y= edit box.
Click the OK button.

Select all of the objects in this view by “windowing.”
Click the View menu > Set 2D View command to display the Set 2D View form. In that form:

Select the X-Z plane option.
Type -17.2073 in the Y= edit box.
Click the OK button.

Select all of the objects in this view by “windowing.”
Click the View menu > Show Selection Only command.
Click the Perspective Toggle button .
Click the View menu > Show Grid command to toggle the grids off.
Click the View menu > Show Axes command to toggle the axes off.
Click the Draw menu > Draw Poly Area command to display the Properties of Object form. Verify that ASEC1 is shown in the Property drop-down box.
In the X-Z perspective view, click on joints 163, 195, 73 and 1, in that order, and press the Enter key on the keyboard to draw an area object.
Click the Set Select Mode button on the side toolbar to exit Draw mode and enter Select mode.
Click on the just drawn area object to select it.
Click the Edit menu > Mesh Areas command to display the Mesh Selected Shells form.
Fill in this form as shown in the figure and click the OK button.

Note: It is difficult to figure out whether to mesh shells 3 by 8 or 8 by 3. It is often easiest to just go ahead and try one way, and if it isn’t right, simply click the Undo button and mesh the shells the other way.

Select all of the objects in the X-Z perspective view by “windowing.”
Click the Edit menu > Replicate command to display the Replicate form. In that form:

Select the Mirror Tab.
In the Mirror About Line area select the Parallel to Z option.
In the Intersection of Plane with XY Plane area, type 0 in the x1 edit box if it is not already entered.
Type 1 in the x2 edit box.
Type 0 in the y1 edit box if it is not already entered.
Type 0 in the y2 edit box.
Click the OK button.

Click the View menu > Set 2D View command to display the Set 2D View form. In that form:

Select the X-Y plane option.
Type 0 in the Z= edit box if it is not already entered.
Click the OK button.

Select all of the joints at this level by “windowing.”
Click the Assign menu > Joint > Restraints command to display the Joint Restraints form. In that form:

Verify that the Translation 1, 2 and 3 boxes are all checked.
Click the OK button.

Click the View menu > Set 2D View command to display the Set 2D View form. In that form:

Select the Y-Z plane option.
Type 20 in the X= edit box.
Click the OK button.

Click the Show Undeformed Shape button to reset the window title.
Click the View menu > Show All command.
Click the drop-down box in the status bar to change the units to .
Click the Define menu > Materials command to display the Define Materials form.
Click on CONC in the Materials area to highlight it (select it), and then click the Modify/Show Material button to display the Material Property Data form. In that form:

Verify 3600 is entered in the Modulus of Elasticity edit box.
Verify 0.2 is entered in the Poisson’s Ratio edit box.
Click the OK buttons on the Material Property Data and Define Materials forms to exit all forms.

Click the drop-down box in the status bar to change the units to .
Click the Define menu > Materials command to display the Define Materials form.
Click on CONC in the Materials area to highlight it (select it), and then click the Modify/Show Material button to display the Material Property Data form. In that form:

Verify that 4.661E-03 is entered in the Mass per unit Volume edit box.
Verify that 0.15 is entered in the Weight per unit Volume edit box.
Click the OK buttons on the Material Property Data and Define Material forms to exit all forms.

Click the Define menu > Area Sections command to display the Area Sections form. In that form:
- Click the Modify/Show Section button to display the Area Section Data form. In that form:
  - Verify that the Material Name is CONC.
  - Verify that the Shell option is chosen in the Area Type area.
  - Verify that both the Membrane and Bending thicknesses are 1.
  - Verify that the Shell option is chosen in the Type area.
  - Click the OK buttons on the Area Section Data and Area Sections forms to exit all forms.

Click the Define menu > Load Cases command to display the Define Loads form. In that form:

Type LIVE in the Load Name edit box.
Select LIVE from the Type drop-down box.
Click the Add New Load button.
Click the OK button.

Click the Define menu > Combinations command to display the Define Response Combinations form. In that form:

Click the Add New Combo button to display the Response Combination Data form. In that form:
- Accept the default Response Combination Name, COMB1.
- Accept the default Combination Type, Linear Add.
- Select DEAD in the Case Name drop-down box (if it is not already selected) and type 1 in the Scale Factor edit box (if not already entered).
- Click the Add button.
- Select LIVE in the Case Name drop-down box.
- Click the Add button.
- Click the OK buttons on the Response Combination Data and Define Response Combinations forms to exit all forms.

Click in the 3-D View window to activate it. Be careful not to accidentally select any objects when you do this.
Click the View menu > Set Limits command to display the Set Limits form. In that form:

Type 25 in the Min edit box in the Set Z Axis Limits area.
Click the OK button.

Select all of the displayed objects in the 3D View window (i.e., all objects in the roof barrel) by “windowing.”
Click the Assign menu > Area Loads > Uniform (Shell) command to display the Area Uniform Loads form. In that form:

Select LIVE from the Load Case Name drop-down box.
Type .3 in the Load edit box.
Verify that Gravity is selected in the Direction drop-down box.
Click the OK button.

Click the Show Undeformed Shape button to remove the display of area uniform loads and to remove the limits that were set.
Click the Run Analysis button to display the Set Analysis Cases to Run form. In that form:

Click on MODAL in the Case Name list to highlight it.
Click the Run/Do Not Run Case button.
Click the Run Now button.

When the analysis is complete, check the messages in the SAP Analysis Monitor window (there should be no warnings or errors) and then click the OK button to close the window.
Click in the window entitled 3-D View to activate it.
Click the drop-down box in the status bar to change the units to .

Right click on the center joint of the upper barrel vault to see its self weight displacement in inches.
Right click on the center joint of the lower barrel vault to see its self weight displacement in inches.
Click the Show Deformed Shape button to display the Deformed Shape form. In that form:

Select COMB1 from the Case/Combo Name drop-down box.
Click the OK button.

Right click on the center joint of the upper barrel vault to see its self weight plus live load displacement in inches.
Right click on the center joint of the lower barrel vault to see its self weight plus live load displacement in inches.

Tutorial - Creating a view into the world of infrared

Tutorial - Creating a view into the world of infrared

Download the tutorial images: ir_tutorial.zip (1,633kb) filter_outline.zip (1,638kb)

This tutorial will take you through the steps of creating an image that serves as a good illustration of a view into the world of infrared. You will need one infrared photograph and one full color photograph taken from the exact same place (again, a tripod is ideal), a photograph of a filter, frame, or similar object, and Adobe Photoshop. For the purposes of this tutorial, I will be using Adobe Photoshop 5.0. The filter or frame will be used to frame the infrared portion of the image in the final composite. If you don't want to deal with finding, photographing, and masking the frame, you can use the one that I used in the above image.

First, open the image of the filter, or frame in Photoshop. You'll need to cut out the entire filter or frame, not including the center portion. If you do not know how to do this, use the filter included with this tutorial, and read up on masking later -- it's a good skill to have in your arsenal of image manipulation tricks.

Now, open both the color and infrared images. You'll probably want to auto-level the infrared image in Photoshop (Shift-Ctrl-L), or manipulate both images to make them look perfect before proceeding to the next step.


	Fig 4. The original infrared and color images (above), and the masked filter (left).

Our goal is to merge all three images into our final product. First, click on the window with the color photo to make it active. We're going to copy its contents into a new Photoshop document. Hit Ctrl-A to select the entire image, and then Ctrl-C to copy it to the clipboard. Now, create a new Photoshop document (Ctrl-N), accept the defaults in the window by clicking "OK" (it will automatically size to the size of the image you're copying), and paste the image into the new windows (Ctrl-V). You will see a copy of the color image in your new window. If you don't see the layers control window, select the menu item Windows->Show Layers to make sure it is visible. Double click the "Layer 1" layer and rename it to something more descriptive, like "Color Image". Now, save the new document and continue. I'm going to refer to this new document as the composite image from now on.

Now we need to copy the entire contents of the infrared photo into the composite image's window as a new layer. Copy the contents of the infrared photo into the new window by following the same steps above. Click on the infrared image's window, hit Ctrl-A and then Ctrl-C. Click the composite image's window, and hit Ctrl-V to paste in the new layer. You'll see a new layer labeled "Layer 1" appear in the Layers tab in one of the control windows. Double-click on "Layer 1" to change the name to something more descriptive, such as ""Infrared Image".

Do the exact same thing with the filter image, and rename the layer to "Filter".


Fig 5. The layers palette and current image

Now we have a document with three layers: a color image, an infrared version of the same image, and a filter. In the composite image's window, you should only see the infrared image with a filter on top of it because the color layer is being blocked by the ones above it in the list of layers.

Our next goal is to size the filter to an appropriate size, and then apply a mask to the infrared layer to let the color image through everywhere except for the area inside the filter. Select the "Filter" layer so that it is hilighted in the layers window. Now, select Edit->Transform->Scale from your menu bar. Click on one of the corner rectangles, and drag the cursor around while holding the mouse button down. When you let go of the mouse button, the filter will resize itself to fit in the bounding box you just specified. Note that you can hold down the Shift key while resizing to force the filter to stay circular. You can also move the filter around by clicking anywhere inside the box and dragging the cursor while holding the mouse button down. Adjust the size and position of the filter until you are happy. When you are done, double click anywhere in the box to commit your changes.

The final step is to reveal the color image in the area around the filter by creating a layer mask to control how different areas within the layer are hidden and revealed. In particular, we want to hide all portions of the infrared image outside of the filter, and reveal the portions inside the filter. We could just erase the entire area around the filter, but creating a layer mask lets us hide the area without actually destroying the original image. Click on the "Infrared Image" layer to make it active. Select the lasso tool from the control panel, and trace a circle along the ring of the filter while depressing the mouse button. Try to keep the lines from the lasso tool completely within the black area of the filter ring. When you've completed the ring, release the mouse button. You should see a moving dotted line along the path you traced. Don't be too concerned about drawing an exact circle -- the filter itself will hide any irregularities in the line.

Fig 6. The
lasso tool

Now that we've selected the portion we want to keep, we just have to create the layer mask. Select Layer->Add Layer Mask->Reveal Selection in the menu. The color image should suddenly appear around the filter, leaving us with our final image. Save the image now -- you're done!

Closing Notes

Infrared imaging has opened my mind to another way of looking at the world. Whenever I see the visual interaction of foliage with man-made object, I often try to imagine how the scene would look in other color spectra. I look up at trees framed by a brilliant blue sky, and imagine brilliant white forms against a black background.

With the quality of the current crop of new digital cameras, exploring infrared photography is finally a possibility for those of us who don't want to deal with the hassles of traditional infrared photography. While it is by no means a replacement for photography in the realm of visible light, it certainly adds a unique, creative twist to digital imaging.

Questions?Feel free to contact me at eric@echeng.com, or visit my website on digital infrared photography at http://www.echeng.com/photo/infrared/

Flat Plate In The X-Y Plane Wuth A Twist

Mesh Area Objects
“Trick” Problem

Click the File menu > New Model command to display the New Model form.
Click the drop-down box to set the units to .
Click on the Grid Only button to display the New Coord/Grid System form. In that form:

Select the Cartesian Tab.
In the Number of Grid Lines area, type 3 in the X direction edit box.
In the Number of Grid Lines area, type 3 in the Y direction edit box.
In the Number of Grid Lines area, type 1 in the Z direction edit box.

In the Grid Spacing area, type 4 the X direction edit box.

In the Grid Spacing area, type 6 the Y direction edit box.

Click the OK button.

Click the “X” in the top right-hand corner of the 3-D View window to close it.
Click the drop-down box in the status bar to change the units to .
Click the Define menu > Materials command to display the Define Materials form.
Highlight the CONC material and click the Modify/Show Material button to display the Material Property Data form. In that form:

Verify that the Modulus of Elasticity is 3600.
Verify that the Poisson’s Ratio is 0.2.
Click the OK buttons on the Material Property Data and Define Materials forms to close the forms.

Click the Define menu > Area Sections command to display the Area Sections form. In that form:
- Click the Modify/Show Section button to display the Area Section Data form. In that form:
  - Verify that the selected Material Name is CONC.
  - Verify that the Shell option is selected in the Area Type area.
  - Verify that both the Membrane and the Bending thicknesses are 12.
  - Verify that the Shell option is selected in the Type area.
  - Click the OK buttons on the Area Section Data and Area Sections forms to close all forms.

Verify that the Snap to Points and Grid Intersections button on the side toolbar is depressed.
Click the Draw Rectangular Area button on the side toolbar or the Draw menu > Draw Rectangular Area command to display the Properties of Object form. In that form:

Verify that the selected Property is ASEC1.

Click on upper left-hand corner grid intersection (Point “B” in the problem statement) and then click on the lower right-hand grid intersection (Point “A”) to draw an area object over the entire structure.
Click the Set Select Mode button to exit the Draw mode and enter Select mode.
Click on the area object to select it.
Click the Edit menu > Mesh Areas command to display the Mesh Selected Shells form.
Fill in this form as shown in the adjacent figure and click the OK button.
Select the joints that are labeled “A,” “B” and “C” in the problem statement.
Click the Assign menu > Joint > Restraints command to display the Joint Restraints form. In that form:

Uncheck the Translation 1 and
Translation 2 check boxes.
Verify that the Translation 3 check box is checked.
Verify that the Rotation about 1, 2 and 3 check boxes are not checked.
Click the OK button.

Click the Show Undeformed Shape button to remove the display of joint restraints and reset the window display (and title).
Click the drop-down box in the status bar to change the units to .
Click the Set Display Options button (or the View menu > Set Display Options command) to display the Display Options for Active Window form. In that form:

Check the Labels box in the Joints area.
Click the OK button.

Select joint 106 (coordinates 7, 12, 0) by clicking on it.
Click the Assign menu > Joint Loads > Forces command to display the Joint Forces form. In that form:

Type -814 in the Force Global Z edit box in the Loads area.
Click the OK button.

Select joint 16 (coordinates 1, 6, 0) by clicking on it.
Click the Assign menu > Joint Loads > Forces command to display the Joint Forces form. In that form:

Type -698 in the Force Global Z edit box in the Loads area.
Click the OK button.

Select joint 32 (coordinates 2, 3, 0) by clicking on it.
Click the Assign menu > Joint Loads > Forces command to display the Joint Forces form. In that form:

Type -901 in the Force Global Z edit box in the Loads area.
Click the OK button.

Click the Show Undeformed Shape button to reset the window display.
Click the Set Display Options button (or the View menu > Set Display Options command) to display the Display Options for Active Window form. In that form:

Uncheck the Labels box in the Joints area.
Click the OK button.

Click the Analyze menu > Set Analysis Options command to display the Analysis Options form. In that form:

Click the Plane Grid XY Plane button to set the available degrees of freedom.
Click the OK button.

Click the Set Default 3D View button to switch to a 3-D View.
Click the Run Analysis button to display the Set Analysis Cases to Run form. In that form:

Highlight (select) MODAL in the Case Name list and click the Run/Do Not Run Case button.
Verify that the DEAD analysis case is set to Run in the Action list.
Click the Run Now button to run the analysis.

When the analysis is complete check the messages in the SAP Analysis Monitor window (there should be no warnings or errors) and then click the OK button to close the window.
Click the Display menu > Show Forces/Stresses > Joints command to display the Joint Reaction Forces form. In that form:

Verify that the Reactions option is selected in the Type area.
Click the OK button and view the support reactions.

Note: The reaction at the joint labeled “C” in the problem statement is virtually zero (0). The reason for this apparently odd result is that the resultant of all the applied loads lies on a line connecting the support points labeled “A” and “B,” and thus by simple statics, the reaction at support point “C” must be zero. Note that you could move the support point labeled “C” anywhere on the structure (except on the line connecting support points “A” and “B” because this would result in an unstable structure) and the resulting reactions would not change.

Sunday, July 01, 2007

Prestressed Concrete Beam

Response Combinations
Output Stations
Prestressing

Click the File menu > New Model command to display the New Model form.
Click the drop-down box to set the units to .
Click the Beam button to display the Beam form. In that form:

Type 1 in the Number of Spans edit box.

Type 30 in the Span Length edit box.

Click the OK button.

Click the “X” in the top right-hand corner of the 3-D View window to close it.
Click the Define menu > Materials command to display the Define Materials form.
Click on CONC in the Materials area to highlight it (select it), and then click the Modify/Show Material button to display the Material Property Data form. In that form:

Verify 0.15 is entered in the Weight per Unit Volume edit box.
Click the OK buttons on the Material Property Data and Define Materials forms to close all forms.

Click the drop-down box in the status bar to change the units to.
Click the Define menu > Materials command to display the Define Materials form.
Click on CONC in the Materials area to highlight it (select it), and then click the Modify/Show Material button to display the Material Property Data form. In that form:

Type 4400 in the Modulus of Elasticity edit box.
Verify .2 is entered in the Poisson’s Ratio edit box.
Type 6 in the Specified Conc Comp Strength, f′c edit box.
Verify 60 is entered in the Bending Reinf Yield Stress, fy edit box.
Type 60 in the Shear Reinf. Yield Stress, fys edit box.
Accept the other default values.
Click the OK buttons on the Material Property Data and Define Materials forms to close all forms.

Click the Define menu > Frame Sections command to display the Frame Properties form. In that form:

Click the drop-down box that reads Add I/Wide Flange and then click on the Add Rectangular item.
Click the Add New Property button to display the Rectangular Section form. In that form:
- Type CONBEAM in the Section Name edit box.
- Select CONC from the Material drop-down box.
- Type 30 in the Depth (t3) edit box.
- Type 18 in the Width (t2) edit box.
- Click the OK buttons on the Rectangular Section and Frame Properties forms to close all forms.

Click the Define menu > Load Cases command to display the Define Loads form. In that form:
- Type LIVE in the Load Name edit box.
- Select LIVE from the Type drop-down box.
- Click the Add New Load button.
- Type PRESTRES in the Load Name edit box.
- Select OTHER from the Type drop-down box.
- Click the Add New Load button.
- Click the OK button.
Select the line (frame) object by clicking on it.
Click the Assign menu > Frame/Cable/Tendon > Frame Sections command to display the Frame Properties form. In that form:
- Click on CONBEAM in the Properties list box to highlight it.
- Click the OK button.
Click the Draw menu > Frame/Cable/Tendons command to display the Properties of Object form. In that form,

Click the Line Object Type drop-down list and select the Tendon option.
Click on the joint at one end of the beam and then click on the joint at the other end of the beam to draw the tendon. The Tendon Data for Line Object 3 form will display when you release the mouse button.

With the Tendon Data for Line Object 3 form displayed, click the Parabolic Calculator button to display the Define Parabolic Tendon Layout for Line Object 3 form. In that form,
- Select 1 from the Quick Start drop-down list in the lower left corner of the form.
- Click the Quick Start button to update the Tendon Layout Data spreadsheet. An additional row of data will be added to the spreadsheet. In the spreadsheet area,
- Click the Refresh button to update the spreadsheet area and the graphical display area.
- Ensure that the Use Calculated Results for This Tendon check box is checked.
- Click the Done button to close the Define Parabolic Tendon Layout for Line Object 3 form and redisplay the Tendon Data for Line Object 3 form.
With the Tendon Data for Line Object 3 form redisplayed, click the Add button in the Tendon Loads area of the form to display the Tendon Load form. In that form,
- Select the PRESTRES load case from the Load Case Name drop-down list.
- Type 200 in the Force edit box.
- Ensure that all of the Friction and Anchorage Losses and Other Loss Parameters are zero. If necessary, type zero in the Curvature Coefficient, Wobble Coefficient, Anchorage Set Slip, Elastic Shortening Stress, Creep Stress, Shrinkage Stress and Steel Relaxation Stress edit boxes.
- Click the OK buttons on the Tendon Load form and the Tendon Data for Line Object 3 form to close those forms.
Click the drop-down box in the status bar to change the units to .
Click the Define menu > Combinations command to display the Define Response Combinations form. In that form:
- Click the Add New Combo button to display the Response Combination Data form. In that form:
  - Accept the default Response Combination Name, COMB1
  - Accept the default Combination Type, Linear Add.
  - Verify the DEAD Case is selected in the Case Name drop-down box.
  - Verify that 1 is entered in the Scale Factor edit box.
  - Click the Add button.
  - Select LIVE Case from the Case Name drop-down box.
  - Click the Add button.
  - Select PRESTRES Case from the Case Name drop-down box.
  - Click the Add button.
  - Click the OK buttons on the Response Combination Data and Define Response Combinations forms to close all forms.
Select the line (frame) object.
Click the Assign menu > Frame/Cable/Tendon Loads > Distributed command to display the Frame Distributed Loads form. In that form:
- Verify that the Load Case Name is DEAD.
- In the Load Type and Direction area, verify that the Forces option is selected and that the Gravity direction is selected.
- In the Uniform Load area, type 2.2.
- Click the OK button.
Select the line (frame) object.
Click the Assign menu > Frame/Cable/Tendon Loads > Distributed command to display the Frame Distributed Loads form. In that form:

Select LIVE from the Load Case Name drop-down box.
In the Uniform Load area type 1.6.
Click the OK button.

Select the line (frame) object.
Click the Assign menu > Frame/Cable/Tendon > Output Stations command to display the Assign Output Station Spacing form. In that form:

Type 4 in the Min Number Stations edit box.
Click the OK button.

Click the Show Undeformed Shape button to remove the displayed frame output station assignments.
Click the Analyze menu > Set Analysis Options command to display the Analysis Options form.

In that form click the Plane Frame XZ Plane button to set the available degrees of freedom.
Click the OK button.

Click the Run Analysis button to display the Set Analysis Cases to Run form. In that form:

Highlight (select) MODAL in the Case Name list and click the Run/Do Not Run Case button.
Verify that the DEAD analysis case is set to Run in the Action list.
Verify that the LIVE analysis case is set to Run in the Action list.
Verify that the PRESTRES analysis case is set to Run in the Action list.
Click the Run Now button to run the analysis.

When the analysis is complete check the messages in the SAP Analysis Monitor window (there should be no warnings or errors) and then click the OK button to close the window.
Click the Display menu > Show Forces/Stresses > Frames/Cables/Tendons command to display the Member Force Diagram for Frames form. In that form:

Select COMB1 from the Case/Combo Name drop-down box.
Select the Moment 3-3 option in the Component area.
Uncheck the Fill Diagram check box.
Check the Show Values on Diagram check box.
Click the OK button to display the moment diagram.

Note: You may want to print this moment diagram for comparison with the one obtained when 20 output stations are specified. To print the moment diagram, click the File menu > Print Graphics command.

Note: For response combinations, when force diagrams are plotted, exact values are only calculated at the ends of each output station. Those exact values are plotted and then they are connected with straight lines.

Click the Lock/Unlock Model button to unlock the model. Click the OK button when asked if it is ok to delete.
Select the line (frame) object.
Click the Assign menu > Frame/Cable/Tendon > Output Stations command to display the Assign Output Station Spacing form. In that form:

Type 20 in the Min Number Stations edit box.
Click the OK button.

Click the Show Undeformed Shape button to remove the displayed frame output station assignments.
Click the Run Analysis button to display the Set Analysis Cases to Run form. In that form, click the Run Now button to run the analysis.
When the analysis is complete, check the messages in the SAP Analysis Monitor window (there should be no warnings or errors) and then click the OK button to close the window
Click the Display menu > Show Forces/Stresses > Frames/Cables/Tendons command to display the Member Force Diagram for Frames form. In that form: