Day 1 What is Engineering and Building Bridges
What do engineers do?
They define problems and design solutions.
18 Major types of Engineers
-Aerospace Engineer - Design and test aircraft, spacecrafts, satellites, missiles, and rockets
-Agricultural and Biological Engineer- use engineering practices towards farming
-Audio Engineer- Sound design
-Bioengineering and Biochemical Engineer- Used to clean up waste, study food supplies, apply knowledge of living systems to solve problems
-Biomedical Engineer- Medical machines and prosthetic
-Ceramic and Materials Engineers- Design things out of exotic materials like computer screens and phones
-Chemical Engineer- design plastics, paints fibers, medicines, papers, fertilizers, etc.
-Civil Engineer- Buildings, railways, bridges, roads, everything in our cities.
-Computer Engineer- Everything about computers
-Electrical Engineer- Works with power, power grids for cities, power for computers, all electronics
-Environmental Engineer- Works towards saving the environment and stopping pollution. Solar power, windmills, etc.
-Geological and Geophysical Engineer- Use earths structures and mining of minerals in other fields of engineering.
-Industrial/ Manufacturing Engineer- Find the most productive ways to produce products using people and machines
-Marine and Ocean Engineer- Design marine structures like boats, harbors, docks, platforms, etc.
-Mechanical Engineer- Work in every level of engineering. Design things like engines, roller coasters, toys, any type of machine or mechanics.
-Mining Engineer- anything to do with mining
-Nuclear Engineer- Nuclear power plants and harvesting nuclear energy.
-Petroleum Engineer- Oil, gas, and plastics.
Today lets talk about civil engineers
Civil Engineers help us design cities. They build our bridges, our roads, the infrastructure needed to maintain a city.
Today we are going to design and build bridges.
We will be using wood sticks to build Truss Bridges
A truss bridge is a bridge whose load-bearing superstructure is composed of a truss, a structure of connected elements usually forming triangular units. The connected elements (typically straight) may be stressed from tension, compression, or sometimes both in response to dynamic loads.
Project:
You will get into groups. On a piece of paper design your truss bridge. Once you have your design a TA will approve it or help you modify it. Once approved you will begin the building process. Use the wooden craft sticks and glue. Good luck.
Truss Types
This page lists the various types of trusses listed in the World Guide to Covered Bridges.
Figure 1.
Figure 1.
Figure 2.
Figure 3.
left. Kingpost.
right. Queenpost.
Multiple Kingpost. With odd number of panels, the center panel is open or has crossed braces as shown by the dashed lines.
Town Lattice, disposition illustrated on 1820 patent drawing shown (only two chords indicated thereupon; one at the top and one at the bottom of the truss.) For railroads and many highways, two secondary chords were made use of for additional strength.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Burr Arch. A multiple Kingpost truss with one or two arches added on inside and outside. Ends of the arch extend below the lower chord and rest on the abutments.
Arch, tied (shown), or two hinged (not illustrated), the latter where the ends of the arch are seated on the faces of the abutments, the present drawing indicating various arrangements of suspension: verticals, diagonals, and crossed X bracing.
Long, with 3 wood diagonals and double timber posts in each panel.
Paddleford. Ends of counterbraces cross both the kingposts and the chords. An inside arch is often added.
Howe, usual type. Three wood diagonals and 2 or 3 iron rod verticals.
Howe, single type. Dashed lines are iron rods.
Howe, western type. Center panel sometimes open.
Haupt, 1839 patent. One remaining example: the Bunker Hill Covered Bridge in Catawba County, North Carolina.
Warren. Single system is in solid lines, double system with added timbers indicated by dashed lines.
Pratt, revised design. Teco-Pratt designs usually have triple timbers. The California design has wooden posts and 2 iron rods as diagonals, crossed in center panel.
Childs, 1846 patent. Diagonals are mortised to chords.
Brown, 1857 patent. Diagonals are mortised to chords.
Figure 16.
Figure 17.
Figure 18.
Figure 19.
Figure 20.
Figure 21.
Figure 22.
Smith, type 2, 1869 patent. Type 3, no patent, reinforced as indicated by dashed center panel timbers.
Smith, type 4 improved, no patent.
Partridge, 1872 patent. Note addition of metal footplates. The seven surviving examples are modified designs with reinforcing rods and additional timber diagonals.
Post, 1863 patent. Iron rods indicated by dashed lines. The last example, the Bell’s Ford Bridge in Jackson County, Indiana, collapsed in 2006.
McCallum, 1867 patent. Posts are flared slightly. One example, the Powerscourt Bridge in Québec.
Suspension or Bowstring. Two examples, both in Ohio.
No Name Truss (neither a Haupt nor a modified Burr), two examples: Sayres Bridge in Orange County, Vermont, and Bath Village Bridge in Grafton County, New Hampshire.