The objective of this session is to explore the latest advancements in emerging technologies that are enhancing the accuracy, reliability, and efficiency of finite element analysis (FEA) in the simulation and design of structural concrete. The focus will be on improving simulation techniques, material models, and computational tools, thereby enhancing the confidence of engineers and researchers in using FEA for concrete structures. The session aims to bridge the gap between cutting-edge technology and practical application in structural concrete, providing solutions to common challenges faced in the modeling and analysis of complex concrete systems.
Learning Objectives
(1) Evaluate the influence of geometric and material nonlinearities on finite element modeling accuracy in reinforced concrete structures. Participants will learn how different nonlinear behaviors affect simulation outcomes and structural performance predictions;
(2) Compare experimental validation techniques, with simulation results for large-scale concrete structures. Attendees will understand the process of aligning real-world measurements with computational models for enhanced model reliability;
(3) Analyze the structural behavior of specialized precast connections using nonlinear finite element methods and bond-slip modeling. Engineers will gain insight into the mechanisms and modeling techniques for precast concrete splice performance;
(4) Differentiate between the simulation strategies for various concrete elements including shear walls, hooked bar splices, and beam-column joints under cyclic loading. This objective provides participants with comparative tools to select appropriate modeling techniques for different structural components.
This session has been approved by AIA and ICC for 2 PDHs (0.2 CEUs). Please note: You must attend the live session for the entire duration to receive credit. On-demand sessions do not qualify for PDH/CEU credit.
Finite Element Analysis of a Reinforced Concrete Cooling Tower – A Case Study
Presented By: Eisa Rahmani
Affiliation: WJE Associates Inc.
Description: Differential settlement was observed in bypass piping adjacent to a 500-foot tall, counterflow natural draft hyperbolic concrete shell structure. The tower features conventionally reinforced concrete for the various elements (shell, diagonal columns, pedestals, and ring beam). The tower is supported by a continuous ring beam foundation that bears on select fill. An elevation survey of the column pedestals identified as much as 7 inches of relative settlement from when the column pedestals were previous surveyed, and a recent outage identified voids in the underlying soil where differential settlement was observed. To assess the structural impact and ensure adequacy, a comprehensive evaluation was conducted using both linear and nonlinear finite element (FE) analysis techniques. Laser scanning was employed to capture the as-deformed shape of the tower. This data was then used to refine and validate the finite element models. Subsequently, the FE models were used to predict the ultimate performance of the tower under various loading conditions, identifying critical safety factors.
Finite Element Analysis of Noncontact Hooked Bar Lap Splices in Precast Concrete Connections
Presented By: Zack Coleman
Affiliation: Wiss, Janney, Elstner Associates, Inc.
Description: The nonlinear finite element method is used to study the ultimate strength and resistance mechanism of noncontact lap splices with standard hooks in precast concrete beams. The concrete material is represented with hexahedral solid elements, while the reinforcing bars are modeled with beam elements. The local bond-slip behavior is also accounted for through an appropriate constitutive law. The modeling approach is validated using the results of four experimental tests of beam-splice specimens from the literature and is subsequently used to elucidate the force flow in the splice region. Parametric studies using the validated modeling approach are conducted to determine the impact of beam depth, number of spliced bars, and tail length on splice strength. The exterior (edge) bars in a noncontact splice are found to carry approximately 25% lower forces than the interior ones. The average splice strength was found to be independent of the beam depth, while it slightly increased with an increase in either the number of spliced bars or the tail length of the hooks.
Unified Finite Element Framework for Reliable Analysis of Reinforced Concrete and Composite Shear Walls under High Cyclic Shear Demands
Presented By: Mohammadreza Moharrami
Affiliation: Nabih Youssef Associates Structural Engineers
Description: This presentation will focus on a unified three-dimensional finite element analysis framework for evaluating the intricate behavior of reinforced concrete (RC) and composite shear wall systems, specifically targeting composite plate shear wall/concrete-filled (C-PSW/CF) structures under high cyclic shear demands where significant material and geometric nonlinearities are anticipated. The framework incorporates robust constitutive models developed by the authors, which remain reliable under cyclic loading and accurately represent essential properties of both concrete and steel. For concrete, key features such as enhanced strength and ductility from confinement, along with damage patterns like cracking and crushing, are effectively captured. For steel, the model represents behaviors including yielding, hardening, and the Bauschinger effect, as well as failure mechanisms like buckling and rupture in steel plates and rebars. This approach reliably predicts stiffness, strength, and ductility in analyzed structures. Comparative studies between RC and composite walls reveal unique confinement mechanisms and failure modes, contributing to an understanding of structural performance. The framework offers a cost-effective and strategically advantageous alternative to experimental testing, allowing detailed assessment of steel and concrete contributions to shear resistance – insights that are often challenging to obtain experimentally. Ultimately, this framework provides engineers and researchers with a powerful tool for the design and analysis of shear wall systems in high-seismic applications, aligning with modern design standards.
Treatment of Uncertainties in the Application of Advanced Finite Element Analysis in the Assessment and Strengthening of Foundation Slab Continuous Beam
Presented By: Jan Cervenka
Affiliation: Cervenka Consulting S.r.o.
Description: After many years of being only an interesting research topic, nonlinear analysis of reinforced concrete structures is becoming a standard engineering tool that is used in the assessment of existing structures as well as in the design of new structures. This development has been significantly supported by the introduction of new safety formats for nonlinear analysis in various national and international codes such as fib model code 2020 or Eurocodes.
An important aspect of any application of these advanced methods is the evaluation and treatment of all uncertainties involved. The paper focuses on the treatment of model uncertainty. Interesting insight into the uncertainty of can be also obtained by studying several recent blind prediction competitions.
The treatment of uncertainties will be demonstrated on a relatively straightforward example of assessment and strengthening design of a foundation slab continuous beam in an industrial building.
Computational Simulation of Concrete Structures: Example Applications and New Developments
Presented By: Ioannis Koutromanos
Affiliation: Virginia Tech
Description: This presentation will focus on three-dimensional finite element analysis of damage and failure in concrete components and systems. Example applications involving cyclic quasi-static and dynamic loading demonstrate the predictive capability of properly formulated, implemented and calibrated tools to capture severe damage such as concrete crushing, bar buckling and rupture. The extension of the methods to the simulation of composite steel-concrete walls will also be discussed. The presentation will also include ongoing efforts to enhance the computational efficiency of refined finite element models. The most notable of these efforts is a recently formulated, selective-mass scaling scheme for static and seismic loading, enabling the significant speedup of explicit dynamic analyses without any distortion to the physically meaningful natural frequencies of the system under consideration.