Influence of Extensometer on Test Value of Yield Strength of Different Materials

The tensile tests at room temperature and high temperature were carried out for materials with obvious yield and no obvious yield. The yield strength measured by the extensometer and unused extensometer was compared. At the same time, combining the force-deformation curve and the force-displacement curve, the reasons for the difference of the yield strength measured by the extensometer and unused extensometer were discussed. The results show that the yield streghth measured by the clamped extensometer is less than that of the non-clamp extensometer for the materials with no obvious yield strength at room temperature tensile test. For the materials with obvious yield, the yield strength of the extensometer is similar to that of the non-clamp extensometer at room temperature tensile test. At high temperature tensile test, the yield strength of the materials with obvious or no obvious yield measured by the clamped extensometer is less than that of the non-clamp extensometer.