Stress calculation from measured strains in the elastic deformation range

Experimental stress analysis using strain gages is carried out in two sequential steps.

Experimental stress analysis using strain gages is carried out in two sequential steps. In the first step the strains created by the stress state under study are measured; in the second step the stress state is calculated from the measured strains. The present paper deals with the second step and is restricted to the elastic deformation range of material.

After a general consideration of the relationships between stress and strain in the biaxial stress state, the formulas for the evaluation of strain gage rosette readings are explained. Particular attention is directed to the prevention of errors in the determination of the principal directions.

A practical example of stress analysis, consisting of the calculation of principal stresses and their directions from strains measured with strain gage rosettes concludes the paper.