Design and testing of a mechanical strain extensometer

Abstract

This thesis’ main aim is to conduct the creation of a mechanical extensometer with its all design levels including its necessary calculations, analysis, manufacturing, electronics and testing of it. The most similar extensometers to the aimed design were investigated in literature and the key point decisions were made about the dimensions and structure. While doing this, essential calculations about predictable error analysis were made; contact force predictions were brought to a sufficient level. The extensometer body design was the initial level in design period. Those followed by the investigation of the possible sensors that could probably feature in the displacement measurement system. Among possible sensors which were presented in the thesis, LVDT was chosen to be used. That trailed by an LVDT selection phase to make decisions about the size, clearance, weight, stroke range and predictions about its behaviors within coordinate analysis when it was mounted on the arms. While those steps were being taken, the elevator of the measurement system is designed and manufactured. Moreover, the extensometer body construction followed that with aluminum 7075. Then the arm construction considering the cooperative elements, LVDT and contact elements was made. Then this followed by design and manufacturing of the calibration unit. The whole measurement system including this unit is constructed and the electronic installations are prepared and the calibration procedure is introduced step by step. The thesis introduces the necessary calculations in a theoretical manner, the whole design and manufacturing periods, variations until the final design in a more practical way and finally the installations of the whole electronic equipment on the measurement system.