An Apparatus to Measure Young’s Modulus
Presented at the 2013 BigSURS Meeting, High Point University
Young’s modulus, a measure of the deformation of a material in response to an applied force, is an integral variable to consider when designing and engineering systems such as buildings or bridges. Young’s Modulus is the slope of a stress versus strain curve. We designed and constructed an apparatus to measure the Young’s modulus of copper and steel wires. Wires were held taut at one end with clamped wooden blocks and the other end is passed over the pulley of a rotary motion sensor. The application of mass to the wire stretches the wire and causes the pulley to rotate. The amount of the rotation is proportional to the distance the wire stretches. The strain is found by the stretch of the wire divided by the initial length of the wire while to find the stress we used the amount of force applied divided by the cross-sectional area of the wire. The stress versus strain graph is then plotted and the Young’s Modulus is calculated by determining the slope of the stress versus strain graph. We report on the Young’s Modulus for each material tested with our apparatus.