Project 2- Parametric model of the International Waterloo Terminal -London, UK using DYNAMO - Visual Programming

Project 2 is an extended version of Project 1. 

My current model has faced many limitations, mainly computational time,  due to which it was not possible to show the required parametric relations.

In this version, exploring the extensive functionalities of DYNAMO, I was able to parametrically vary the spacing of the truss element on the curve, and also overcome the computational time issues to a greater extent. The following applications of DYNAMO are incorporated in this project.

• Placement of truss onto the curve 
• Randomizing the curtain panel system for 2 materials - glass and steel

Parametric Variation of Truss system on the terminal layout.

In project 1, it was time consuming to place each adaptive truss on the preset adaptive points on the curve. Using the visual programming tool-DYNAMO, I was able to achieve this goal without having to manually place the truss on the curve. 

In my dynamo program, the first step was to create points on the curve where the truss needs to be placed. Dynamo creates these points with the flexibility to change the spacing of these points such that the number of trusses can be varied. 

First step was to draw the curve in Revit. In dynamo using set model element, these curves are selected. The element type chosen for the selected lines is "Curve element". The output of the curve element is linked to the curve length and an integer slider is used to give the spacing between these points. The curve length and spacing parameter are then fed into a code, using CODE BLOCK, stating that the points begin at 0 length, ends at curve length with the curve spacing as a variable. 

This code is then connected to a function called "point at distance" allowing DYNAMO to give the output as points. Same procedure is followed for the other two curves. The output of the created points are listed using "List Create". This list needs to be transposed to get the 3 points on different curves as one set rather than having all points on one curve as a complete set. 

The transposed list is then linked to the family type of the truss using the function Family Types to define the loaded adaptive family and placement of this family type as adaptive points by using ADAPTIVE COMPONENTS BY POINTS function. On running this program, REVIT automatically places the trusses on the curve at the set spacing. Here are 2 more examples to show the placement of trusses with a spacing of 5ft, 10ft and 15ft. 

Now a second DYNAMO program is established to randomize the patterns of the panel system by material on the roof surface created. 

The roof surface is divided into horizontal and vertical grids and a rectangular panel is loaded onto the divided surface. An excel file is used to randomly place the panels. This project uses 2 materials-glass and steel. In DYNAMO code,  the "Divided surface families function is used to select the divided surface. A file path function is added to read the excel file. The excel file is a matrix of 0's and 1's which in accordance with the python script created is used to associate these numbers with the materials used. 

Materials by Name function is used to add the required materials which in this case are steel and glass. The excel file and the materials are linked to the python script which is further connected to element set parameter by Name which takes in the surface i.e the element, the material which is the parameter and value which is from python script to randomly place these materials on the panels of the selected surfaces. 

Blue - Glass

Grey - Steel

International Waterloo Terminal-London, UK

Introduction

The International Terminal at Waterloo in London, UK designed by Nicholas Grimshaw and Partners, is a 400 meters long massive curved train shed which varies sinuously in length, by gradually expanding towards the station end. The design is based on the concept of bio-mimicry, which is defined as the design and production of materials, structures and systems that are modeled on biological entities and processes. In this structure, the glass panels mimic the flexible behavior of scaly Pangolin. It is capable of responding to the changes in the air pressure as trains move through the terminal. 

Parametric Modelling:

The main parametric relationships involved in this project were the parameters defining its structural form relating the span and curvature of individual arches. It is a series of asymmetric trusses where the center point is displaced towards one of the sides enabling the arch to rise more steeply on the west side to clear the structural envelope of the train while gently inclining over the platform on the east. 

The complete roof model becomes a series of instances of one parametrically modeled arch, varying the span parameter. Two bowstring truss systems form the roof of this structure. .

The longer trusses have tension rods on the inside and the shorter trusses have them on the outside. Longer trusses have stainless steel cladding thus reducing solar gains and shorter trusses have glass cladding. The two primary elements involving in parametric expression for Waterloo train shed are the horizontal spanning distance B and C of minor and major axis respectively as shown in the figure 3. A scaling factor hx/H is used that can be computed as shown in Figure 3, using simple Pythagoras theorem for a right angled triangle.

Here are some of the images through the different stages of development of this model.

Truss 

Curve created for the path of the trusses using equations for 2 sine curves and a straight line and made to vary parametrically.

The truss elements are placed on the adaptive points of the curve such that lengths of each of the arch varies with the width of the terminal.Form is created on the outer edge of the longer truss and the inner edge of the shorter truss, such that the tension rods are placed accordingly.

Final model with the curtain panels made of glass on the roof of the structure.