A piezoelectric sensor assembly for measuring a force quantity on a structure includes at least one piezoelectric sensor, each including an element and two electrodes each projecting outward from the element. An electronic processor of the assembly is configured to receive data from the sensor, wherein the data includes a voltage with a magnitude that is indicative of a dynamic load (i.e., amplitude modulation mode) placed upon the structure. The processor may be configured to interrogate the piezoelectric sensor for its resonant frequency change which is indicative of the load applied to the structure at low operation frequency and to which the piezoelectric sensor would not otherwise respond well. The dual mode operation of the piezoelectric sensor extends the frequency range of the strain measurement from the dynamic range to static or quasi-static range.