Measuring strain without a Wheatstone bridge

Engineers are concerned about physical failure characteristics associated w ith their designs, whether those designs are airplane wings, bridge structu res, engine shafts or hard drives. One of the more common measurements made in the physical world is strain. By measuring strain on critical areas of the design, it is possible to predict potential failure mechanisms. This ar ticle defines strain, reviews the types of strain measurements encountered in the physical world, and looks at the resistive strain gage itself.