Experimental study of the deformability of a truss with parallel chords

The aim of this study was to comprehensively investigate the deformative properties of a welded truss with parallel chords under field test conditions and to compare the experimental results obtained with the results of finite element modelling. The main focus was on determining the relationships between the magnitude of the applied load and the corresponding deformations (deflections) of the structure under the action of static external forces. Field tests were performed on a full-scale welded sample of a truss with parallel chords with a step-by-step static load from a hydraulic jack, with strain gauges and clock-type indicators installed at characteristic locations to monitor deformations and deflections, as well as simultaneous numerical modelling in the LIRA software package to obtain and compare load-deformation curves with the results of field measurements. The experimental data obtained included quantitative indicators of truss deflections at different levels of applied load, so that at a load of 0.35 t, the deflection is 25 mm, and with an increase in force to 1.05 t, the deflection increases to 118 mm. Load-deflection graphs were created, demonstrating the linear behaviour of the structure within the studied load range. A comparison of the experimental results with the finite element modelling data showed a high degree of consistency. The data obtained allow to refine the stiffness characteristics of the elements and increase the reliability of predictive calculations regarding the deformability of the structure. The developed methodology can be used to improve the accuracy of the design and calculation of welded trusses and to adapt design models to real operating conditions