Structural preliminary analysis


#1

This studio is a part of my Degree thesis in BIM Design ( Degree in Architecture and Building Engineering -University of Bologna) where I developed how is possible use BIM in all the design process (from the beginning to the end) to save money and time. I shown how it’s possible do preliminary analysis in Revit environment to give a right path where develop all parts of Architecture, Structure and MAP design.

In this little article I’d like show how is possible have a structural preliminary analysis that gets on with the architectural shape!

GOAL Understand the behaviour of structure with Dynamo tool. The purpose is to give a useful instrument to architects to understand the structural system that they need (material, structural dimension …)

CONSTRAINTS

<span style=“text-decoration: underline;”>Architectural Shape- </span>I started with a simple house with flat roof, so I outline a simple box. Now I have to Put the windows, and doors, but where?! So I decided to create a Dynamo path to introduce a parametric structure inside “the box”.

<span style=“text-decoration: underline;”>Structure-</span> I started to divide the space with a steel structure, to be precise structural framing: truss structure with brace.

Truss: Because I decided to do a simple dimensional analysis where it’s possible to study only the axial stress (compression and tension) where the bending moment is negligible .

• Circular pillar: to simplify the calculation of sections

• Steel :because has the same behaviour in compression and tension

Load Condition In a very simply way I decided to study the gravity load and wind load with a uniform distribution without any multiplier factor.

THE WAY !

I started to analyze for every geometrical plane the load condition and stress behaviour

1

load condition

2

stress behaviour

From the science of construction I know

s=N/A< s*

with

N= ql[Kg] axial stress

A=(3,14)r^2 [mm2]area of pillar

s*=430[Mpa] in this case I decide to use S275;Fe 430 (Italian code)

So I can have

A=N/s*

This give me the possibility to understand the dimension of the pillars in function of the geometry of the structure, of the load condition and of the material (? value) that I use. In a simplifying way I neglected the buckling of the structure.As you can see in the picture I created a dynamo path with the idea that I mentioned before.

variaz

Truss with symmetrical condition of load and geometrical

variaz

Truss with variation of symmetrical condition and geometrical

All the geometrical parameters and material can be variable. So in function for boundary conditions I can understand what can happen in my structure.

ADVANTAGE

With this Dynamo path the Architect in a simple way can understand the space that he needs for structure.So He can solve in a preliminary step the clash detection problems and define a good workflow information with Engineers.