Draftsmen/Drafter.

Draftsmen draft. Just kidding. They do draft but they are better than that, well! Some are. The need for a draftsmen might be meek in an ideal European sense, with all the automations and sort. Even without the automations, a Structural Engineer is expected to be able to do the drafting himself/herself. 
But I don't live in Europe, do I? And the need also arises due to the sheer scale of some projects. The main task of Engineers is to design and analyse the structures. And it does take time. Hence, the need for draftsmen.

Now what does a Draftsmen do. They draft. They are expected to be good in drafting softwares, whether it be 2D, 3D or even 4D. Though I have never been a part of a 4D project YET. Some general softwares can be the CAD lineup, Revit, Dynamo, Sketchup and the list goes on. 
They should have the knowledge as how it all works. Some cases are not always general, and they have to come up with alternatives, just like Engineers in this case. For example, I had to import a DXF file of a Revit file into ETABS. Now ETABS don't read block elements, even if it's just a line. I had this dilemma and a draftsmen came up with the idea of breaking the lines into poly lines which should have been read by the ETABS theoretically. We couldn't solve the problem in that case and I had to draw many lines over the DXF file for ETABS to read. But you get the general idea.

As I said in my second blog, the final product of us, Structural Engineers are Drawings. Detailed by all the analysis and Design by the Engineers. Now in a general scenario, the Draftsmen does this job. Although we have to sit with them and tell of the particulars. If we use a particular beam size, the draftsmen should create it in the final Revit Model. I should tell the workflow for you guys to understand I guess. So here it goes. 

I am talking about the Revit Model
Architecture Model   ->   Preliminary Structural Model   ->    Revisions    ->    Engineers Input   ->
Final Model.
Revisions can be done both by the Architecture and Engineers. 

A Revit model can give all the required Drawings : Plan View, Sectional View, Schedules, Beam and Column sizes, Thickness of Slabs and Walls, Reinforcements Details. In short, all the information required for a report.
Here is an example from a Model I practiced upon. 

A 3D practice mode. 
Mini Bosses told me not to use actual Projects for my blogs.

Plan View of First Floor.

Second Floor.

The Beam sizes. I could only load Steel Beams.

A Sectional View.


It can also help with the Bill Of Quantities (BOQ), I just did one yesterday - 15th Dec. 

So yeah, this is the work of a Draftsmen in a nutshell. 

Comments

Post a Comment

Popular posts from this blog

Ritz and Eigen.

Image
Ritz, not Rizz and Eigen Vector are two ways of solving a Modal Analysis problem. It is what ETABS use while doing the Modal Analysis. Today's blog will be about the difference between these two. EIGEN-VECTOR : It determines the undamped free-vibration mode shapes and frequencies of the system. What free-vibration means in our term is that there is no external loads acting on it for any period of time, just the initial conditions. The idea of bending a ruler and allowing it to reverberate. The natural modes obtained through this provide an excellent insight into the behaviour of the structure.  But remember, it's the free-vibration response while the structures will be under various different loads. What should be done then? Here comes the Ritz Vector. RITZ-VECTOR : Research has indicated that the natural free-vibration mode shapes are not the best basis for a mode-superposition analysis of structures subjected to dynamic loading : Wilson, Yuan and Dickens, 1982. I stole this l...
Read more

Modifiers.

Image
This is one of the coolest concepts I have properly learnt at my job. I do know I will learn lot more on this. It's the Stiffness Modifiers.  It is a modification factor that is generally used in the properties of cross-section such as Moment of Inertia, Shear Area, Torsional Constant etc. It can also be used for Mass and Weight as per requirement. Modifiers for a typical Beam. Now why is it used? As the loads act on the structure, it will tend to generate cracks on the tension zone. Thus, reducing the area of cross section and stiffness of the member. 1 means the structure would take all of the loads, while 0 won't be taking any. It is kind of a paradox; the structure would resist all the loads if it is not cracked, and we know it will crack. In other way, we want the structure to not take the load as it will eventually crack. Concrete is weak in Tension. As per codes, IS Code ACI Code Now I have two great examples for putting my case. One is related to a torsion modifier I st...
Read more

Slab On Grade in ETABS.

Image
First let's know what an SOG is. The full form is Slab on Grade/Ground. One use for it to create an equal level for construction. Imagine a large area foundation with minimal area at a lower level. It is easier to provide reinforcement in a single plane; hence the lower level can be raised by filling it with soil or some other substances. Then it acts as one level foundation. I came across a scenario where I had to model an elliptical tank like structure, no columns in between. It was to be filled with soil. As you can see, I have attached an image, the slab span is quite large in between. The plan of the model. Imagine an ellipse with R1 = 37 m and R2 = 65 m. Now if you run the model as a normal slab, which it kinda is, one can easily guess the response. You can guess with experience that is, or a different case if you are a genius. I will tell you how the response would look like if you run it as a normal slab. You would get lots of local modes (I am assuming you know what local ...
Read more