A THEORETICAL-STUDY OF THE OPTIMUM LINEARITY CONDITIONS OF THE STRUCTURE OF AN AXIAL EXTENSOMETER

Extensomers are always designed with small deformation theory. Thus, i t is always difficult to enhance the linearity and the full scale at t he same time. In the present paper, the mechanics models of extensomet ers are summarised, and the relationships between the strain and the d isplacement, even for large deformation, for every model is studied. T he results show that there are optimum linearity conditions of the str ucture of the axial extensometer for each model. On the basis of this, the linearity and the full scale can reach 0.05-0.1% F.S. and 80%, re spectively. (C) 1997 Elsevier Science S.A.