Youngs modulus of nylon essay
Youngs modulus of steel in kg/cm2
If the range over which Hooke's law is valid is large enough compared to the typical stress that one expects to apply to the material, the material is said to be linear. With the measurement for the diameter being 0. This is the value that I would obtain by plotting any size of? The shear moduli of a few common materials are given in the table below. There is a clear elastic region at the start of the graph followed by a strain-hardening region. The layout of my apparatus in general also created reliability problems, as I had to make sure I was perfectly level with the bottom of the nylon thread to take an accurate reading, and with the amount of readings being taken it is likely that there was a mistake made during this process at some point. I am therefore going to conduct an experiment very similar to that of the original ones, but applying weights in intervals of 10g 0. Any real material will eventually fail and break when stretched over a very large distance or with a very large force; however all solid materials exhibit nearly Hookean behavior for small enough strains or stresses. For instance, it predicts how much a material sample extends under tension or shortens under compression.
Diameter of 0. Variation in Readings The breaking point of the nylon should always have been the same value. Enough readings were taken in each experiment to clearly highlight where anomalies had appeared, allowing these values to be discounted and therefore not influence any results or averages where applicable.
Experimental Technique Using a manual wooden ruler, accurate only to 1mm, left large room for error when taking readings in the experiments.
Youngs modulus experiment
My graphs indicate that the elastic region lies up to a force of 3. Other unintentional variables will also be present in the experiment, notably the cross-sectional area of the nylon wire, which will decrease as more strain is applied and the material stretched. At this point the material has begun to permanently deform and will no-longer return to its original point, however its strength is now increasing, as displayed by the reducing positive gradient of the curve plot. Some parts of the experiment however used better technique, for example the micrometer which was accurate to 0. Ranges from a length of 0. The Young's modulus directly applies to cases of uniaxial stress, that is tensile or compressive stress in one direction and no stress in the other directions. With this practice applied to the curve, it is clear that it does in fact follow the same sort of trend as the first graph. The graph of each experiment can be found on the next three pages. Region of Elasticity This region of the graph is identified as the part where the points most closely appear to form a straight line. Breaking Point. Maximum Strength This is the point at which the strain-hardening curve reaches its peak point.
After this point the curve will begin to drop, representing the necking region and the approach to breaking point. Other unintentional variables will also be present in the experiment, notably the cross-sectional area of the nylon wire, which will decrease as more strain is applied and the material stretched.
Youngs modulus of nylon
Hence, the force required to increase the length of a thin wire of steel is much larger than that required for aluminum or copper. For example, as the linear theory implies reversibility , it would be absurd to use the linear theory to describe the failure of a steel bridge under a high load; although steel is a linear material for most applications, it is not in such a case of catastrophic failure. Breaking Point. Enough readings were taken in each experiment to clearly highlight where anomalies had appeared, allowing these values to be discounted and therefore not influence any results or averages where applicable. The reference wire A is used to compensate for any change in length due to a change in the temperature of the room. It is also worth noting that at this point a substantial amount of weight will be dropping so arms and feet should be kept back from below the experiment and all persons in the vicinity should be on their feet to allow them to move back quickly if required. Further, a vernier scale is attached to a pointer at the bottom of wire B and the scale M is fixed to reference wire A. This is the point at which the material has weakened to rupturing point and displays the stress required to break the material. The graph of each experiment can be found on the next three pages. The experiments all seemed very vulnerable to sources of human error and so in future investigations I believe the set-up and technique needs to be adjusted to reduce the reliance on human measurements and contact with the nylon.
These wires are suspended side-by-side from a fixed rigid support. Through research earlier in my project I am able to identify different areas of the graphs. For example, carbon fiber has a much higher Young's modulus is much stiffer when force is loaded parallel to the fibers along the grain.
My graphs indicate that the elastic region lies up to a force of 3.
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