Probabilistic damage simulation for strengthening design of concrete structures

Abstract

Shape memory alloy (SMA) is a smart material that can be applied as an internal and external reinforcement of reinforced concrete flexural elements in order to increase ductility and strength of the members. Column‐beam joint is a critical section of a concrete structure which under seismic and unexpected heavy loads may lead to failure of entire of the structure. Therefore, this numerical investigation aims to increase strength and mitigate risk of failure of the joint by employment of SMA plate. To do so, an experimentally investigated joint under 1000 load combinations has been simulated in Ansys APDL. Each load combo contained two axial loads and one bending moment; load values have been randomly selected through a procedure in MATLAB. Some nodes in plastic hinge region of the joint were chosen as control points. Generated load values were applied in the simulation, and stress of the control nodes was recorded. This process continued for all 1000 combos. Then, obtained results were imported into MATLAB for a probabilistic analysis. Probability of 0.95 quantile of stress of each node was calculated in order to design the required plate thickness at each node. Some numerical examples were applied on the designed plate. Results demonstrated that the designed SMA plate gets the risk of failure from the joint away and increase strength of the joint.