Stress measurement method by PVDF gage and its application to impact test for concrete

The direct stress measurement method by polyvinylidene fluoride (PVDF) gage is introduced. The dynamic piezo constant of PVDF gage is calibrated on the SHPB set-up. Influences of stress concentration, Poisson effect and friction effect on the pulse and the dynamic piezo constant of PVDF gage are discussed. The impact compression experiment of concrete is performed with PVDF gages. The uniformity of stress within the concrete specimen is analyzed with the data from the PVDF gages between the bar and the specimen, and combined the data directly measured from the strain gage glued on the specimen. The dynamic stress-strain curve is derived.