Strain Gauges

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-->This semester we decided to attach strain gauges to the large solar oven in order to characterize the strain of the glass over a range of temperatures. We want to characterize the glass, because people in Nicaragua have had problems with glass cracking and breaking. The gauges come in pairs. Each pair measures strain in two perpendicular directions along the surface.  We attached one of these pairs to the top glass outside the oven, one on the bottom glass inside the oven, and one on a piece of thermally neutral material. The purpose of the thermally neutral material is to characterize the gauge itself. We can subtract the strain reading from the thermally neutral material, from the readings from the other surfaces to obtain measurements of the actual strain. After several experiments, the cycling of temperature changes caused the gauges to become detached from the surfaces. We were able to collect some data, but we do not have enough data from the thermally neutral material to analyze the data from the inside and outside glass.

We have another adhesive we want to use to bond the gauges to the glass. Next semester we plan to attach another strain gauge pair to the thermally neutral material, inside glass and outside glass and collect enough data to figure out what the strain of the glass is as a function of temperature.