Identification of the short-term full-section moduli of pultruded FRP profiles using bending tests

Three- and four-point bending tests are traditionally used to estimate shear and flexural properties of Pultruded Fibre-Reinforced Plastic (PFRP) structural shapes. In the framework of Timoshenko’s beam model, the beam rigidities can simply be obtained from linear combinations of the experimental deflections. However, several measurement uncertainties may affect the parameter identification. To analyze this drawback, a new test configuration was compared with the common three- and four-point bending test configurations through an extensive experimental programme concerning wide-flange commercial profiles. A parametric study was carried out by varying the span length and, in the case of the four-point bending tests, the relative position of the applied loads. The influence of the load and deflection measurement errors was analyzed and proper uncertainty bands for the computed rigidities were provided.