Math Exploration Task

A simple beam bridge that is flat across and supported at the two ends. A longer beam bridge can be held up along the middle by piers standing in the river. The weight of the bridge itself, plus the load that it carries, plus gravity are the downward forces are spread evenly across the length of the bridge. The upwards forces that hold the bridge up come from the piers. The Confederation Bridge in Canada is a famous beam bridge.

The first example of an external force is the static (dead) load, this refers to the gravitational forces acting on the bridge itself. Every structure has to be able to support the weight of its own materials in order for it not to collapse, this is before any live load is applied to it. Another example is dynamic (live) load which refers to traffic, from people or vehicles, which move across the bridge and apply additional weight to it increasing the magnitude of vertical forces acting on the bridge. But environmental factors such as changes in temperature, precipitation and winds can also create vertical and horizontal loads on the bridge. (Bagga

Each separate truss (of the dimensions 920x5x50mm) consisted of a Pratt truss with nine diagonal members on each side of the centre. The model was tested in sufficiently isolated condition by tutors. It successfully passed the initial weight test, and satisfactorily resisted horizontal forces. Once fitted onto the testing rig, loads were applied and increased incrementally. Slight deformation was observed before failing at 12.5 kg, at which force a collection of members failed in succession, concluding the test.

Several students are doing Science Fair projects at Woodstock Middle School and I am one of the seventh grade students. The topic I shall be doing is on how bridge structure affects the weight bearing capacity. I chose this specific topic to guide bridge builders in the right direction on what bridge is safest for public use. The key topics I plan to research on include the following: Beam, Warren Truss, suspension, cable-stayed, and arch bridges. I shall use the scientific method to guide me through this process.

Clark Eldridge, an engineer from Washington State, had designed a trusted, conventional suspension bridge that would cost eleven million dollars. He requested that amount from the Federal Public Works Administration. However, Leon Moisseiff developed a design modification that would make the total cost of building the bridge much less- only eight million dollars. He swapped out the twenty-five feet long sturdy trusses as the form of support for the much cheaper alternative of 8 foot long girders, which were proven to be an insufficient form of support from the collapse of this bridge. His design accounted for an overall thinner bridge; and since his was the cheaper option, it was chosen for construction. However, the width of the bridge in comparison to the length, as well as the absence of trusses which would provide stability, are both part of Moisseiff’s “cost-effective”, yet impractically unsafe design. Since his design was flawed, he is mainly responsible for the bridge collapse. However, the board of engineers who approved his design are also partially responsible for the bridge collapse, as this unsafe design was allowed to be constructed. Meanwhile, it is imperative to remember that theories on aerodynamics were not fully developed as of the time that this bridge was constructed. Therefore, the full effect of oscillating forces was not properly accounted for due to the

All are very effective and work well if built in the right conditions. The thing that separates these bridges from one another is that they all have different points of compression and tension. Tension is two forces of opposition that pull away from each other to keep it from being pulled together. If you imagine a rope in a game of tug-of-war, the rope has a lot of tension because it is being pulled apart, but the opposing force inside of the rope is trying to keep it together. The same can be applied to a bridge truss because the tension truss is opposing the compression truss by pulling the bridge apart. Tension also pulls the platform of the bridge by stretching it to keep the bridge from collapsing. Compression is two forces in opposition that push an object together to try to compress it. If you think of someone standing on a soda can, the soda can tries to resist being squished, but the weight of the person standing on the can still squashes it. This example can also pertain to the truss on a bridge. A compression truss opposes the tension truss by pulling the bridge together. Compression is also placed on the top of a truss and in its bases. The compression at the top of the bridge counteracts with the tension of the platform and balances out each force. The compression in its bases is from the weight of the platform and trusses. Bridge engineers calculate the tension and

We choose design #1 because the truss bridge is a bridge whose load bearing superstructure is composed of a truss, a structure of connected elements forming triangular units. The stressed from tension, and compression helps carry heavier masses. We chose the truss bridge, for it is a very rigid structure and it transfers the load from a single point to a much wider area. A truss is an arrangement of structural members that are connected together to form a rigid frame work. Modern trusses are made of structural steel. All bridges have 4 main characteristics: form, span, material, and travel surface in relation to the structure. A truss bridge is one form that a bridge can take and there are at least 30 different kinds of truss

A truss is a complex structure. Each piece needs to fit perfectly to perform its role, and anything less will mean that the truss will be unstable or simply does not hold an applied load. A truss bridge requires detailed construction and knowledge of how it distributes the forces. With the lack of this knowledge your truss could fail to withstand an applied force.

Students have had to see Newton’s laws at least once in their lives, and even with that they probably do not know their application to such things as bridges.

The use of support beams to connect each end may have contributed to bridge supporting power, preventing weaknesses at the ends, adding to complete bridge support. The use of stronger, fast drying glue may have aided in creating stronger connections between the features and bundles throughout the bridge. These stronger connections due to the use of better glue may have allowed for a greater load to be supported before cracking of glue would occur. Lastly, creating a shorter bridge length may have helped decrease area for a load to be supported. Our bridge was much longer than the average of other groups, which had supported higher loads, possibly demonstrating that a shorter bridge would be a factor in supporting higher

The masterful works of art, known as bridges, are some of the most complex structures people design. With absurdly complicated bridges, like the Lucky Knot Bridge in China, to an everyday bridge that you would see in North Carolina, engineers everywhere must go through the same process of making sure these bridges are safe and secure. The dedication and amount of hours that go into deciding the structure, what addons will overall make the bridge itself stronger, and what makes these bridges economical checks to see that they are universally safe, and to hopefully prevent another Tacoma Narrows Bridge tragedy.

The “Pratt” Truss bridge invented by Thomas and Caleb Pratt in the 1840’s is a unique bridge that combines lightweight and strong structural support providing a very supportive lightweight wide bridge. The bridge uses both diagonal and vertical beams forming a triangular structure. The diagonal and vertical shape of the beams are very strong and light because the triangular shape that the beams make are ridged, utilizing a minimal amount of timbers. The material used in these bridges is also a big part of what makes it unique to other bridges. In the early nineteenth century a majority of bridges was consisted of stone, but wood and iron were better than resisting tension, this is why the United States had many Truss bridges. Truss bridges can also be built basically anywhere. These bridges can span far or short as they want while maintaining structural integrity. To describe the Truss bridge in a few words or phrases, I would say that they are very economically friendly, strong, light, and very versatile.

Because of advancements in today’s technology in construction field, many types of bridges are being constructed depending on the requirement and their suitability for the situations.

Purpose: The purpose of this Physics Lab is to investigate what factors determine the amount of flexion of the cantilever. Hence, the objective is to establish a relationship between the length of a cantilever, which may give some insight into the physics of cantilevers.

Following tables and graphs show the result of the experiment. The tables will demonstrate the experimental and theoretical deflection for each case. The graphs will show the relationship between the load applied and deflection, in addition to compare the experimental deflection and theoretical deflection.