Lot has been spoken about structural design software. Many would have also spoken why software knowledge alone is not sufficient to be a successful civil & structural engineer.
I have written a blog before about the need of improving the basics in structures along with learning a structural engineering software. In another blog I have also written about gaps in education that civil engineering students should cover along with learning ETABS tutorials
Many ask me if ETABS is better than StaadPro. Though each software has its own advantages,
In this blog am focusing on why ETABS is popular than other analysis and design software.
1. GLOBAL USEAGE FOR STRUCTURAL DESIGN
(Note : Dont miss the last point!)
ETABS comes from CSI - Computers & Structures Inc., one of the most reputed company offering structural engineering software and Earth Quake engineering software .The ETABS software is used by thousands of engineering firms in more than 160 countries as per the CSI website. CSI is a brand established in 1975 and they have decades of experience in software development. CSI products are used for the most prestegious projects in the world including the One World Trade Center in New York. CSI has engineers with practicing experience and established academicians on research jobs and consistently improves their tech. The technical support is quite spectacular and the kind of online ETABS Course available on the web is quite world class that lets you master the software quickly.
2. EASE OF STRUCTURAL MODELLING
ETABS has one of the most easy and intutive interfaces for modelling. ETABS allows the user to model with a very friendly graphical mode. There is also an editor mode which rarely needs to be used as the graphical interface gives you sufficient options to model complicated structural models with ease.
You have options to model slabs as membranes for the yield line theory behavior or as shells for replicating more realistic stiffness based load distribution.
ETABS is flexible and powerful for generating auto lateral loads as per any popular code. Seismic mass generation,diaphragm defenetion etc are very easy. Those who has used older software products will get a feel that ETABS improved up on the shortcomings of other old products. To put it in another way, they are leaders since the user feed back of a predecessor leader was accounted in producing this world class structural software product. Basically the modelling mode in etabs allows user to create the real technical structural condition of the members as in site. It also allows the user to modify properties to match with the site behavior. An example of this is stiffness modification of members.Another example is the option to release compatibility torsion in beams that helps achieve the real structural behavior and do away with thumb rules and therby economising the structural design.
ETABS also gives a powerful but an easy way to simulate soil structure interaction. Many times people ask,if they should fix or pin the base of a column. In reality it is neither of this. You can bring in fairly matching soil properties for the support conditions by using ETABS. There are many more advantages in learning ETABS which I will be updating in this blog after a while.
3. CUSTOMISED FOR LEVELLED BUILDINGS
ETABS is customised for levelled buildings. RCC multi levelled building is the most common building structure that you will find across the globe. When a software is custom made for suiting just that, it is bound to be popular. The customisation allows replication of levels quickly.
ETABS is compatible with many CAD formats like AutoCAD and it is super easy to draw a plan in CAD and then import that in to ETABS. You can also get different layers in AutoCAD separate in ETABS and choose what you want to import. Same way ETABS model can be taken back to AutoCAD. This is more useful if we use plugins and tools like CSI Detailer or CSI XCAD for producing drawings.
CSI also have a plugin that allows interoperatability with REVIT. Though many experts dont recommend using this feature unless absolutely needed,some body who likes to have that option can easily interlink etabs and Revit using the plugin.
If you are interested to know what Revit can do in structural design cycle, watch the video provided in our Revit course page
5. EASE OF SHELL RESULTS INTERPRETATION
This is my best one! The real reason I abandoned many other software and embraced etabs!!
I need to mention and explain a bit of history to explain why I score ETABS high on this !
Way back in 2002-2005, I worked in 2 of the most leading Bangalore based structural consulting firms. In one among them, I had to model a few buildings which used mivan technology for its construction. Probably for the first time in Bangalore this technology was being used for construction. How is it related to structural modelling - Well! when you have the entire walls as RCC , we should account for its stiffness in analysis.There is no separate columns.Every thing is a wall. All enthusiasm and energy drained when we realised that the software we had at that time could not handle this.We failed to conceptualise it in any other way than modelling all the walls. The software we had took more than 24 hours for analysis. Have had days when we worked overnight! Overnight working and a bit of support from the software company helped a bit. Then came the realisation that when all walls and slabs are shells and when the windows and door positions needs to be accounted accurately for proper meshing interconnectivity of slabs and walls. What if architects revise the door positions! Yes that finally happened and that started happening more often. The time that we have spent to stitch the joints after revisions to avoid connectivity error was huge! At that time we had NO ETABS!
Experiencing the biggest difficulty in meshing shells in early phase of my career makes me thank ETABS many times for the way it handles shells.The way the edge constraints work in ETABS is a boon for the new generation engineers. Also note that meshing is internal in etabs and probably its only in etabs that this is internal. (For those who did not understand what I mean by this,please go to the ETABS Training page in this website and fill the contact form and mention there that you want to know about this. I will help you to understand.)
Let me conclude by stating some more features that I like in ETABS
It allows design of all members super correctly and easily.
Sway Index of columns will be calculated by ETABS to determine if a column is sway or non sway. No conventional structural analysis software does this.Effective length of column is determined by software based on stiffness and not based on thumb rules. In most other software,user need to input if a column is braced or unbraced.
Super easy features to design slabs as strips.
Analysis & Design of footings as shell is possible
There are many more advantages using a structural design tool like ETABS.One point I want to mention again - Use it with the right, sound basic principles.ETABS is as good as you! It gives you all the right options to adopt to achieve the real conditions that you need to simulate.How you use it is what matters.Understanding of all the essential basics in structural engineering is a pre requisite to use any software and ETABS is not any different!