Presentation on theme: " Each student has a file in their folder that will help guide the project. The file contains a rubric that explains how it will be graded. The project."— Presentation transcript:
Each student has a file in their folder that will help guide the project. The file contains a rubric that explains how it will be graded. The project will create at least 5 bridges. Pictures of the bridges and their written explanation will be submitted. Students get to choose which style of bridge to spend more time on.
The West Point Bridge Design software is a free program that you can download from the West Point College. Start the program and just keep pressing next/finished until it brings you to the design interface. You can come back later and experiment with different options. The system lets users save bridge files. However, the final product for this project will be a Word Document.
The bridge is made of joints and beams. The joints are where the beams join together. The designer can choose where the beams go. Also, the beams can be made of different thicknesses and different kinds of steel. These options combine to make any kind of structure.
Using MS Word and screenshots The project will be submitted in a Microsoft Word file. Students will submit 5 bridges with 5 descriptions. To get a picture of a bridge (or a picture of any window) use the keyboard and press the “Print Screen” button. This button is in the top right corner of the keyboard. Then, paste the screen shot onto the document.
WPBD: Getting Started Starting the Design Program Joints and Beams Using MS Word and Screenshots
It can be fun to make a spectacular design that costs a lot of money. A beam that is longer will cost more money. A beam that is thicker will cost more money. The more beams you have the more money it will cost. Also, options can be set up at the beginning of a design that will increase cost.
In reality people do not want to spend a lot on a structure. To enter the WPBD contest, making a bridge less costly is the main focus. Make each beam just strong enough to hold the weight it needs. Look at the data on the beam to see how close it is to breaking. The beam should be close to breaking, but not actually break.
People have different ideas on what a bridge looks like to make it beautiful. You can create a bridge to suspend letters or shapes. You can make a bridge using different colors of steel. You can make a bridge that moves in odd ways. Choose what you think is beautiful.
It is not easy to put the truck in the water. The bridge its self has weight, this is called dead weight. The truck has weight, this is called live weight because it moves. Try to make the bridge hold up from dead weight, but not live weight. By doing this, the truck will take a swim.
An expensive bridge A less costly bridge A Beautiful bridge A splash bridge
Excavation is when machines are used to remove large amounts of dirt and debris. By excavating the sides around a bridge, the bridge can be built lower. The lower bridge has less distance to cover. Excavation also creates more area for a bridge builder to place beams and joints. By choosing the excavation option, designers can be successful on any of the different kinds of bridges.
The length of the bridge is called a span length. Some times it is more cost effective to build a bridge that does not have to go as long. Reducing the span length reduces costs of steel and increases cost of excavation. Increasing span length increases the cost of steel and decreases the cost of excavation.
The simulation software enables designers to choose from three different types of steel. Carbon steel is the cheapest and least strong. High strength alloy steel is medium cost and strength. Quenched and tempered steel is the most expensive and most strong. The best bridge designs will use a mix of all three types.
Hollow tubes make use of steel without any material in the center. An engineer will save money because they will purchase less materials. However, the cost of producing hollow tubes is higher. In many cases hollow tubes are a better buy. Thick beams tend to be more cost effective.
The slenderness rating is a calculation of how thick a beam is compared to its length. A beam that is long and thin is more slender. A beam that is short and thick is less slender. Beams must not be too slender. The simulation will automatically report an error with a slenderness score above 300.
Compression is the physical force pushing things together. If the beam is thick enough, it will resist compression. A beam that is too thin will compress together and start to bend. Longer beams are more likely to compress. The simulator highlights compression problems in red.
Tension is the force that pulls things apart. Steel is very good at resisting tension. A steel cable or steel beam can often hold many tons of weight. In some cases, a bridge may have a beam break from tension. If a beam is pulling apart from tension, the simulator will highlight the beam in blue.
The data table shows numerical values of forces placed on the beams (members). When optimizing a beam for cost, it is good to have a beam that is nearly breaking. Try to have the compression and/or tension get near 100% without getting to 100%. In real life, the bridge would be built stronger in case of unforeseen events. However, for the program, if the truck works one time it is a good bridge.
Slenderness Compression Tension Using the data table
The written portion of the project requires text in paragraph form. Start out with a topic sentence. The topic sentence just repeats the question. For example, if a teacher asked what a “Splash Bridge” is, a student should start the paragraph mentioning the word splash bridge. “A splash bridge is the name used in the rubric for a bridge that has the truck fall into the water.”
The middle sentences of a paragraph should support the topic sentence. Try to use professional vocabulary and specific information. Avoid vague references that do not support the topic sentence. “The splash happens because the bridge can hold the dead weight, but not the live weight. This is why we test bridges in simulations first”
Just like an essay needs an ending paragraph, a paragraph should have an appropriate closing sentence. Some times a student can reword the topic sentence for a good closing. “By examining a splash bridge, engineers can see the how the bridge is effected by the truck’s weight.” Another way to end a paragraph is to make an “I” statement. “I enjoyed watching the truck fall in the water!”
There is a lot of opportunity for students who enjoy this kind of simulation. A student can go to the West Point web site and participate in the contest to win $5,000. A student can get a job as an engineer or an architect. Other similar programs that you might like are called Computer Aided Drafting.
Topic sentences Body sentences Closing the paragraph Opportunities for bridge designers