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.
Calculations were performed to determine the effectiveness of the design of the platform. Allowing for a safety factor of 1.5 times the design weight of 10kg and considering the bridge must not be overdesigned; plans were made for the bridge to fail at 25kg, 2.5 times that of the design weight. According to the calculations, the bridge would hold a load of over 15kg and experience failure at 20kg in the members. These calculations were later disproven in the testing, breaking 8kg earlier than expected, due to unforseen errors. An analysis of the bridge design and calculations has been included at the end of this report.
The Lift Coefficient CL is calculated using the graphs 1-6. In this report counting the squares method is used to calculate the area between the curves for pressure distribution on the upper surface and lower surface. The area gives the lift coefficient at particular angles
Adding additional uplift capacity to the stringers while minimizing changes to the beam cross section will be essential to preventing future damage to the stringers
In 1989, an earthquake caused the top deck of the bridge to collapse. This has raised concern in recent years in the case of a large scale earthquake. During an inspection in September of 2009, a 1.5 inch crack was found in a structural truss called an eyebar. The system of the truss is meant to distribute report will describe the tensile load from the weight of the bridge over 4 eyebars. One of them being broken, this same load was now distributed between only 3 eyebars. Because these eyebars were not designed to carry extra load, it became crucially important to repair the eyebar as soon as possible. However, because the bridge is so old, its mechanisms were more complex than what would be designed now in the current day. The engineering company C.C. Myers was contracted to do the repair. C.C Myers decided to repair the eyebar by welding a crossbar to the saddles which had been placed on each end of the broken eyebar (Alfrey, 2010). Four tie rods were then bolted to distribute the tensile load (Reid, 2010). This repair was completed in only 70 hours (Carlsen,
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
One thing that has been brought up as a concern for the hospital is using unistrut versus structural steel to hold booms from the ceiling. Unistrut tends to move too much and causes too much movement in the booms when doctors are in surgery. The engineer on the project has started to investigate this problem and has agreed to use structural steel instead of unistrut. In my Structural Systems I class, we learned how structural steel deflects with certain
Two weeks ago, there was an incident at Truss Construction Shop. A hoist operator was placed into an induced coma due to a large part of a Truss breaking apart during a QA Truss load test. The Truss broke apart because the testing was pushed beyond the threshold. This
The use of steel rebars was started in construction in 18th century. Cast iron was used in the earlier age. Cast iron rebars were of high quality, and there was no corrosion. The technique was refined by embedding the steel bars in concrete. Square twisted steel bars (deformed bars) were introduced in 1960s but these were phased out due to their inherent inadequacies. Later the steel rebars of high yield strength were produced by raising carbon (>0.5 and <1.0 wt% content) as well as manganese contents. Carbon was added to steels in order to achieve strength and later on it was realized that higher content of carbon created problem of brittleness and accelerated rate of corrosion (due to the presence of higher proportion of cementite phases
In addition to the primary and design load calculations required in bridge design, four design limit states must
After construction of the triangular base, we added connecting supporting pasta bundles throughout the base. Next, we constructed a square of pasta bundles in the center of the base, with a bundle going through the middle, creating two triangles. We added this additional support in the center of the bridge as a means to provide additional support to the area where the weight of the supporting load was to be applied during testing. After constructing a base of triangles, connecting bundles, and extra support in the center, we moved onto construction of the top. For the top of the bridge, we constructed a constant flat surface of spaghetti, laying each individual noodle
Note: This assignment contributes 10% towards your final mark. This assignment is due at 5pm on Tuesday, April 24th during Week 7. Submit your report to the assignment box on the 3rd floor outside of the drawing office in the Mechanical Engineering Building or via email by that time (firstname.lastname@example.org). Late assignments will not be marked unless a doctor’s certificate or equivalent is provided. Plagiarism will be dealt with in accordance with the University of Sydney plagiarism policy. You must complete and submit the compliance statement available online. Mathematical derivations are expected to be done by hand except where the use of Matlab
Heavier trains requiring stronger track have resulted in striking increases in the weight of rails. Because of heavier trains, joints in the tracks have become fragile. Designing engineers have sought to reduce the number of joints by lengthening the rails. The customary length when locomotives were introduced was three feet, but in the 1830’s this was increased to fifteen or twenty feet. Early in the 20th century the most common length for rails was thirty feet, when 40-foot freight cars become generally available.
The Tacoma Narrows Bridge was designed for a wind speed of 100 miles per hour and a static wind pressure of 30 pounds-force per square foot but unfortunately the bridge failed at a wind speed of less than half and a static wind pressure of one-sixth (Delatte, 2009). This phenomenon raises a big question mark on how this is possible. At first, resonance was suspected to be the main cause of the bridge failure (The New York Times, 1940). After some proper research and thorough investigations by engineers, they came up with several theories on how did the bridge collapse. The primary cause of the collapse lies in the general proportions of the bridge and the type of stiffening girders and floor. The ratio of the width of the bridge to the length of the main span was so much smaller and the vertical stiffness was so much less than those of previously constructed bridges that
Steel has an intricate past and present. When scientist discovered how to mass-produce steel the moment marked the modern society’s genesis. During that time, the United States Steel Corporation dominated the steel industry. Today, the steel industry sees competition not only from native business but from abroad as well. Steel is used in almost every major commercial load bearing structure. Combined global competition and mixed uses has increased the need for civil engineers to conduct specialized research.