Numerical Simulation of Steel Reinforced Concrete (SRC) Joints

Abstract

This paper presents a three-dimensional finite element model to confirm experimental tests carried out on steel reinforced concrete joints. The nonlinear behavior of this concrete is simulated, along with its reduced capability to resist large displacements in compression. The aim was to obtain the plastic behavior of reinforced concrete beams with a numerical model in the same way as obtained experimentally, in which the reduction of strength in the post-critical stage was considered to simulate behavior until structures collapsed. To do this, a nonlinear calculation was necessary to simulate the behavior of each material. Three numerical models provide a moment-curvature graph of the cross-section until collapse. Simulation of the structural elements is a powerful tool that avoids having to carry out expensive experimental tests. From the experimental results a finite element model is simulated for the non-linear analysis of steel reinforced concrete joints. It is possible to simulate the decreasing stress behavior of the concrete until reaching considerable displacement. A new procedure is discussed to capture the moment-curvature diagram. This diagram can be used in a simplified frame analysis, considering post-critical behavior for future research.Metals 2019, 9, 131 2 of 20 to analyze the real behavior of the beam from the elastic to plastic range and collapse. Load was defined as a prescribed displacement located in the center of the beam to know its plastic behavior. The first model, P03, was a 3.6 m long pinned beam with a concentrated load in the center, with a steel reinforcement of four bars (12 mm in diameter). The second model, P04, had the same reinforcement, but with the addition of a 2 m long HEB-100 cross-section in the central part. The third model, P05, was a reinforced concrete beam capable of supporting a similar load to the P04 model, but without the metallic section, with a steel reinforcement of two bars (16 mm in diameter) and two bars (20 mm in diameter) ( Figure 2). Our conclusions were similar to those reached by recognized studies with more complex frames in which loads were applied in a reverse direction, such as in reference [2]. Recent research, such as in reference [3], shows that high-strength reinforced concrete structures confined with tubular profiles and embedded metal profiles display the best behavior. Metals 2018, 8, x FOR PEER REVIEW 2 of 20chosen because of the test frame's characteristics. Different constructive solutions were considered to analyze the real behavior of the beam from the elastic to plastic range and collapse. Load was defined as a prescribed displacement located in the center of the beam to know its plastic behavior. The first model, P03, was a 3.6 m long pinned beam with a concentrated load in the center, with a steel reinforcement of four bars (12 mm in diameter). The second model, P04, had the same reinforcement, but with the addition of a 2 m long HEB-100 cross-section in the central part. The third model, P05, was a reinforced concrete beam capable...

Equivalent Frame Model with a Decaying Nonlinear Moment-Curvature of Steel-Reinforced Concrete Joints

“…The moment-curvature graph was obtained from the solid model [18]. It was made to compare the numerical model results with those obtained with the tested prototypes [17].…”

“…2020, 10, x FOR PEER REVIEW 6 of 19 the breakage of the section by including a drastic reduction that simulated the loss of resistance due to the deterioration of the concrete and breakage of reinforcements in the moment-curvature graph ( Figure 5). The moment-curvature graph was obtained from the solid model [18]. This novel procedure consisted of a three-dimensional finite element model validated by the experimental models to obtain the moment-curvature graph from the strains and moments in the section.…”

“…The moment-curvature graph was obtained from the solid model [18]. This novel procedure consisted of a three-dimensional finite element model validated by the experimental models to obtain the moment-curvature graph from the strains and moments in the section.…”

“…In Montava et al [18], three solid numerical models were tested to understand their behavior and obtain the moment-curvature graphs required in the present research.…”

“…The main objective of this investigation is to obtain a numerical model of a moment-curvature graph to be used in a simplified frame analysis, from post-critical behavior to collapse. References [17,18] have been used in order to validate the experimental data versus the numerical data.…”