In laboratory 5, "Boom Construction Competition", the concepts of material failure, stress and strain were introduced, as well as booms and the work that they do.The students had been asked to construct a boom. The booms were tested, and competed within the lab. The ideal design was a boom that had a long arm, at least 1.5 meters, and was able to carry objects as heavy as possible.
The main principle of a boom is to transport heavy objects from one place to another place. Booms were frequently used in constructions. For example, cranes were very important tools that are used in most construction sites
There are two important considerations in the boom design. One is the maximum weight that the boom can lift/move, under the condition that the boom is mobile or stationary. The other one is that the maximum height that the boom can lift through.
Based on these two considerations, the material choices are very important. The most effective consideration of material choices is material failure. There are three modes of material failure.
This kind of failure usually is caused by the object's environment. When two or more objects react with each other, the original objects will be weakened and/or one or more new objects will be formed. The processes are called corrosion. Erosion refers to that the objects are affect by weather, such as wind or water.
2. Thermal Shock
This kind of failure mostly is caused by temperature changes. When the object is exposed to the big temperature changes, which is from high temperature to low temperature, during a short term of time, the object will be contract. The failure is not uniform that it usually occurs on the weakest part of the material.
3. Breakage under Load
This is the most common kind of failure. There is a maximum load that a material can undergo in both tension and compression. Overload will lead to either cracks (tension lo…