ABSTRACT
Following observations of out-of-plane instability in slender ductile structural walls in some recent earthquakes, this mode of wall failure has been and is being investigated by several research groups. Analytical, numerical and experimental investigations have been conducted to study this failure mechanism as well as its controlling parameters. This mode of failure was numerically simulated by the authors using curved shell elements available in DIANA commercial program, which was the first attempt to model the evolution of out-of-plane deformation in rectangular RC walls and the subsequent instability under in-plane cyclic loading and without introducing any artificial eccentricities. This paper summarizes the validation process of the model which comprised simulation of the out-of-plane instability observed in several tested wall specimens as well as a blind prediction exercise conducted to predict the in-plane and out-of-plane response of a singly reinforced flanged wall specimen. The consistency of the model prediction was evaluated by a set of parametric studies on the parameters known to be influential on progression of out-of-plane deformation. The model is found to be capable of predicting the out-of-plane instability observed during the tests and could capture cyclic response of the specimens reasonably well in terms of global parameters such as lateral load-top displacement curves and local parameters including nonlinear strain profile at the wall base.
