A Study on the Limitation of Applicability of Fixed Angle Softened Truss Model ;;
A fixed angle softened truss model has been developed in order to predict both shear strength and deformation of reinforced concrete members. The model takes into account the contribution of concrete by accuming the angle of cracks in the postcracking concrete that coincides with the reinforced concrete principal compressive angle determined by the applied stresses. Therefore, this model is capable of predicting the contribution of concrete from the govering equilibrium and compatibility equations including the shear stress and strain developed along concrete diagonal crack. However, the model has a limiting range to be applicable for reinforced concrete members. This research proposes a new algorthm of fixed angle softened truss model capable of removing the limitation of applicability. The proposed algorithm adopts a new conception of constitutive laws. The average normal stresses of concrete in the x- y- directions can be calculated by transforming the principal stresses of concrete. The proposed algorthm is verified by comparing to the test results.