UNIT 2
Activity 2.1.1 Centroids
Finding the centroid of a shape like a circle or square is very easy. However for an object such as a beam, the centroid is only represented by the geometric center if the material is uniform or homogenous. Beams and other materials are often reinforced with a different material. Such reinforcement likely changes the location of the centroid from the geometric center. It is important that engineers account for this in their designs.
Activity 2.1.2 Beam Deflection
Engineers must look for better ways to build structures. Less
material typically means that structures will be lighter and less
expensive. Knowing the moment of inertia for different shapes is an
important consideration for engineers as they strive to make designs
lighter and less expensive.
In 1981 at a Kansas City Hyatt, a walkway holding hundreds of people collapsed during a party. The collapse killed 114 people and injured 200 others. When building this walkway, designers and engineers made serious errors that allowed the collapse to occur under the weight of so many people. In such a design, every part must be analyzed to ensure that it can perform its intended function without failing. One planning tool that engineers can use is the free body diagram. Free body diagrams show all forces that act upon a body or part. The information identified in a free body diagram can be used to determine whether a part is adequate.
2.3.1 Stress Strain Calculations
On January 28, 1986, NASA launched a shuttle orbiter named Challenger. Approximately 73 seconds after launching, Challenger exploded, killing all seven of its crew members. Christa McAuliffe, a high school teacher, was one of the crew members aboard the Challenger. Why did the Challenger explode?
Engineers are technical problem solvers. The way in which engineers solve problems varies. In general engineers implement a logical approach, or method, in solving the problems that they encounter.
Engineers are technical problem solvers. The way in which engineers solve problems varies. In general engineers implement a logical approach, or method, in solving the problems that they encounter.
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