Modal and Nonlinear Analysis of Cracked Concrete Beams and FE Modeling for Damage Assessment

For theoretical and practical investigation of damage increase on dynamic characteristics of concrete structures can use analytical model to extract dynamic characteristics such as natural frequency and mode shape. In this research، results of experimental and finite element analytical model for various specimens were compared. These specimens include RC beams and pre-stress concrete beams that constructed in laboratory. In this paper، one of the specimens was modeled for showing how modeling cracked concrete beams and specials notes related to nonlinear static analysis and modal analysis. In test case، damages are produced step-by-step applying the static load and modal characteristics of the specimen are measured via modal test immediately after loading step. However، in finite element modeling case is two complicated problems. Firstly، because concrete is a composite material، modeling of cracked concrete is very difficult. Secondly، in RC structures، both the concrete and steel have nonlinear behavior. Results of this research include peculiar notes that can be useful for other similar researches.