Google SketchUp

This week the first of my books arrived (The strains upon bridge girdersand roof trusses... by T. Cargill). This book is a scanned copy of quite an old book (1873) and some of the pages are damaged due to the wear of time. It does have some relevant sections on uniformly distributed weights, determining strains graphically, the strains upon the web of gidrers, and the lattice girder. I have started to read the relevant sections, and will use them to hepl me formulate my research question and hypothesis.

I also started working with google sketchup. I did the four beginners tutorials to learn the basics of the programm (http://sketchup.google.com/training/videos/new_to_gsu.html). the program is really interesting for this project as it will allow me to make a virtual 3D model of the bridge before i physically make it. Through the tutorials I made a chair using two different techniques.

More books

Today I put in an order for some books on my topic, some of which are quite general and some of which are very specific (written by university professeurs...). I am hoping that this will be usefull and will allow me to decide which specific aspects of girder bridge design I would like to test and help me formulate my hypothesis. I also plan to go to a toy shop soon and order some specific parts of meccano so that I may begin to get a feel of what will be possible with this construction medium.

The books I ordered are:

• The strains upon bridge girders and roof trusses: including the warren, lattice, trellis, boqstring and other forms of girders, the curved roof and simple compound trusses - T.Cargill
• Invention by design: how engineersget from thought to thing
• Structures: or why things don't fall down
• An introduction to the design of beams, girders, and columns in machines and structures with example

Meccano

I had an idea that meccano might be a good material to use for the structures being experimented on due to it's simplicity and its resemblance to steel members used in actual truss bridges. I had a breif play with some pieces and was able to make a simple truss shape quite quickly. if i were to use meccano though i will need a lot more so this will probably involve some research into ordering specific parts.

Meeting with Mr Rawson 18-1-11

Today I had a brief meeting with Mr Rawson. We discussed how far I was with the research and what was left to be done before I can start experimenting. Mr Rawson sugested downloading Google Sketchup so that I can make a 3D design of the truss bridge I plan to build to test before I actually start making the bridges I will test.

Initial research

Through the initial research of my extended essay I aim to gain enough knowledge to formulate a hypothesis on how changing one of the variables involved in constructing a lattice girder bridge will affect the bridges overall streingth.
I have found both online civil engineering lecture notes and civil engineering text books that have given me the basic knowledge of calculating the forces acting on steel members in lattice girders how the members act under tention and compression.
The main topics of my research have been:

• lattice girders
• tention and compression
• roof trusses
• steel bridge design

I took a trip to the university library of Basel to find aditional resources but was unable to find any as Basel University do not teach technical subjects. to resolve this problem i may have to travel to a library in Zurich or Muttenz.