Structural modelling of textile-reinforced concrete elements under uniaxial tensile loading

The paper presents a non-linear structural model for evaluating the macro-structural response as well as the distribution of the internal stress resultants of textile reinforced concrete composites under uniaxial static loading. The equilibrium equations and the appropriate boundary conditions are derived on the basis of the variational principle of the minimum potential energy approach. Various aspects related to the unique microstructural behavior associated to the bonding mechanism of the yarns and the concrete matrix, as well as the nonlinearity of both materials, are taken into consideration and implemented in the variational principle. The obtained set of nonlinear equilibrium equations is formulated according to the mixed formulation which yields a set of first order nonlinear ordinary differential equations. The solution procedure is conducted by the mixedhalf-station interlacing-grid finite-difference scheme and by Newton-Raphson method. Results provided by the proposed model are compared to experimental tests from the literature and demonstrate its generality, accuracy, simplicity, and its easy implementation in various experimental setups. It is further demonstrated that the presented structural model can successfully capture the macro-structural response and gives an insight into the micro-structural mechanism involved in the load carrying capacity of the TRC composite element.