Civil Engineering Structural Concentration Essay

Civil Engineering Structural Concentration - Essay Example Basically, the properties and characteristics of a polymer depend upon its structure. The strength of the plastics can be determined from a measurement known as the Young’s modulus. Young’s modulus is the ratio of stress over strain, i.e. elasticity and is measured in units of Pascal (Pa). Unfilled plastics usually have a Young’s modulus of less than 3.5 GPa at room temperature (â€Å"Characterization and Failure Analysis of Plastics†, 53). Their strength is also temperature sensitive and can be affected by environmental factors as well. The strength can be improved by using fillers and fibers as reinforcements in order to enhance the mechanical properties of the plastic. The tensile strength of most plastics is less than 35 MPa. A lesser tensile stress means a lesser rigidity (MatWeb, n.pag.) but this can be increased by using resin of higher Young’s modulus so as to provide with better reinforcements. The designing of the plastic also has a signif icant role in improving the strength of the plastic (â€Å"Characterization and Failure Analysis of Plastics†, 53). Lower quality or recycled plastics have a lower tensile strength and can break at a very low magnitude of stress. This is because after recycling the plastics are â€Å"down cycled† causing them to become less rigid and more amorphous thereby causing them to break at a lower stress level. The load on the above hanger is caused by hanging clothes. In this case the force or load is caused by the weight of the clothes which depends upon the thickness of the fabric. On average clothes weigh about 2 to 5 pounds (lbs) with the weight being centered at the middle point of the hanger. Continuous weight on one point of the hanger results in breakage. The fracture shown in Figure 1 illustrates that breakage has occurred midway along the length of the hanger leaving 18.5 cm on both sides. The hanger being