Tutorial 01 - Creating a simple Box Shaped Barge
In this first tutorial we will walk you through the creation of a simple barge complete with swim ends.
First of, start Archimedes and single left click on the default title "Blank Hullform". It should become live and you can then edit it. Call it "Barge" and hit enter to confirm your change. You now have an empty model with a new title.
This barge is going to be 100m long, 25m beam and 5.50m deep. Swim end will be 10m long each end and taper to a 2.0m deep transom plate with the same taper on the bow. See image below for simple GA.
This barge can be modeled in Archimedes using only 4 sections, each one representing Aft Bhd, Aft Knuckle, Fwd Knuckle and Fwd Bhd. We will also flesh out the midbody with additional, equally spaced frames to show the process of defingin and adding a parallel section.
Creating the Root Appendage
First of we need to create a root appendage. A model can have as many appendages as you wish (within the limits of the memory on your machine). In the model tree right click and select "Add Appendage".
Next we will edit the appendage name in the same way we changed the name of the model. Left clicking the appendage name and change it from "New Appendage " to "Main Hull".
Note: There is no specific requirements, naming convention or limits when naming appendages. You only have to ensure that the use of characters "<" or ">" is used.
Defining a Section Using Offsets
We will define the first section, Aft Bhd, by directly entering the offsets. Change the name of the default "Blank Frame" to "Aft Bhd" and leave the longitudinal position as is. We will use the aft frame location as the origin of our Y axis (i.e. @ y=0.00m)
Change the left hand view from the model inspector to the offsets table and select the only offset there (0.00m, 0.00m). Then in the 2D body plan view (X and Z axis showing) hold the Ctrl key down and then left click to roughly create your rectangle representing the aft bhd cross section. You should then be left with something looking like Fig 03 below.
Tip: Selecting an offset and "shift clicking" interactively moves an offset to a new location.
We can then change the values to the following:
Flicking back to the Model Inspector page and left clikcing on the icon of the Main Hull appendage then righting clicking and adding a new frame we can edit the properties of this frame to "Aft Knuckle" @ 10.00m (hitting enter after each edit to confirm).
This time we will use snaps to enter the exact values interactively. Select File->Preferences->2D Tab and change X and Z snap to 0.50m as below:
By refering to the status bar along the bottom you can tell where the cursor is in 3d space at any time. Combined with the user defined snap settings allows the quick and accurate placement of offsets on a section.
Snap offsets can be toggled on and off by checking and unchecking the menu item View->Snap Offset. With snaps on, Ctrl clicking in the 2D section view will add an offset to the nearest point of intersection on an imaginary grid with horizontal and vertical spacing defined by the values in the x and z snaps on the preferences form.
To aid with the placement of additional offsets, you can turn on additional frames "ghosted" into the background in the 2D view. Select the frames tab and select the current frame you wish to operate on and check the ones you wished to appear in gray behind the live frame as shown below. You can check or uncheck as many additional frames as you wish.
So to define with a ghosts ection behind and snaps turned on you just need to Ctrl click in the approximate location of the new offset. The section at the Aft Knuckle can be quickly added. See image below:
Duplicating the Frames
Now we can take the existing frame for the Aft Bhd and copy it to the location of the fwd bulkhead. Archimedes MB has a versatile system fro modifying and duplicating frames and appendages. All operations can be distilled down into moving and scaling on a single entity or to an array of entities. Add to this the option of toggling the creation of a copy of the entity moved or scaled and you add the copy and mirror functionality.
Therefore we wish to create a copy of the Aft Bulkhead at the extreme fwd end of our barge so by selecting the Aft Bhd Frame (htereby making it current) and opening the "Transform" dialog, (Ctrl-T or Edit->Transform) we can tell Archimedes to create a copy of the current frame and move the copy 100m fwd along the Y axis and 0m along the X and Z axis. See screenshot below:
Note changes highlighted in red above. Pressing the execute button will leave you with a new bulkhead at the fwd end of your barge. Navigating to the Model Tree you can change the name of your new frame to Fwd Bhd. Note how it has been added to the end of the list of frames for the appendage. Frames are always sorted in order of increasing Y location.
Finally, we want to define the parralel midbody. Opening the "Create Element Array" dialog (Ctrl-A or Edit->Create Element Array), we can select the frame "Aft Knuckle" from the drop down box, toggle Y from pitch to total (clicking the button toggles between options) and asking Archimedes to create 10 copies along the length of the body. Execute button creates the new array.
This is a very simple use of this tool and it cna be used to create arrays of frames or appendages along lines differing increments across all 3 axis.
The end result should be the following (after some renaming of mid frames):
A link to the file may be found below: