Find the Von Mises stress at the location of the strain gages.
A rectangular strain gage rosette attached to an aluminum surface comprises 3 identical gages (gage factor = 2.1) of nominal resistance 200 ohms are associated into a Wheatstone bridge having 3 other resistance values also of 200 ohms. The output of each bridge is connected to an instrumentation amplifier set to a gain of 100. Consecutive output voltage changes from each of the amplifiers after the component is subject to loading are 0.0335, -0.0103 and -0.0213 correspondingly. Stating any assumptions, determine the von Mises stress (in MPa) at the location of the strain gages.