Performance of Multifiber Beam Element for Seismic Analysis of Reinforced Concrete Structures

2014 ◽  
Vol 14 (06) ◽  
pp. 1450013 ◽  
Author(s):  
Xuan Huy Nguyen
Keyword(s):  
Reinforced Concrete ◽  
Damage Mechanics ◽  
Seismic Analysis ◽  
Axial Strain ◽  
Nonlinear Behavior ◽  
Bending Moment ◽  
Axial Direction ◽  
Beam Element ◽  
Shaking Table ◽  
Rc Structures

This paper presents a simplified modeling strategy for simulating the nonlinear behavior of reinforced concrete (RC) structures under seismic loadings. A new type of Euler–Bernoulli multifiber beam element with axial force and bending moment interaction is introduced. To analyze the behavior of RC structures in the axial direction, the interpolation of the axial strain is enriched using the incompatible modes method. The model uses the constitutive laws based on plasticity for steel and damage mechanics for concrete. The proposed multifiber element is implemented in the finite element Code_Aster to simulate the nonlinear behavior of two different RC structures. One structure is a building tested on a shaking table; the other is a column subjected to cyclic loadings. The comparison between the simulation and experimental results shows that the performance of this approach is quite good. The proposed model can be used to investigate the behavior of a wider variety of configurations which are impossible to study experimentally.

CFD Application for Performance Based Safety Verification of Reinforced Concrete Beam in Computer Simulation Building Fire

2012 ◽  
Vol 601 ◽  
pp. 190-195
Author(s):  
Chia Chun Yu ◽  
Shih Cheng Wang ◽  
Cherng Shing Lin ◽  
Te Chi Chen
Keyword(s):  
Reinforced Concrete ◽  
Fire Protection ◽  
Fluid Dynamic ◽  
Bending Moment ◽  
Fire Intensity ◽  
Fire Damage ◽  
Rc Beams ◽  
Fire Dynamics ◽  
Rc Structures ◽  
Building Fire

More than 90% of the buildings in Taiwan use reinforced concrete (RC) structures. Before or after fire damage, whether the RC structure accord Performance Based Design (PBD) fire code or safe evaluation are important in building fire protection verification. However, obtaining fire thermal parameters detailed quantitative data from building fire tests or actual building fires are difficult. Therefore, computational fluid dynamic (CFD) integration to simulate fire scenarios has been widely utilized in fire protection engineering. This study utilizes Fire Dynamics Simulator (FDS) fire model and PHOENICS field model software to simulate fire development and beams inner temperature variation. The structural strength estimated using beam cross-sections temperature to investigate dynamic ultimate bending moment (Mu) of RC beams. This integration method can investigate the influence of different beam positions, fire intensity, fire duration and fire damage sustained (two or three faces heated) for RC beams fire protection safe verification.

scholarly journals Effect of Embedment on Generated Bending Moment in Raft Foundation under Seismic Load

2020 ◽  
Vol 26 (4) ◽  
pp. 161-172
Author(s):  
Abeer A. A Hanash ◽  
Mahmoud D. Ahmed ◽  
Abdulmotalib I. Said
Keyword(s):  
Reinforced Concrete ◽  
Physical Model ◽  
Sandy Soil ◽  
Excitation Frequency ◽  
Bending Moment ◽  
Shaking Table ◽  
Seismic Excitation ◽  
Seismic Load ◽  
Embedment Depth ◽  
Raft Foundation

This research shows the experimental results of the bending moment in a flexible and rigid raft foundation rested on dense sandy soil with different embedded depth throughout 24 tests. A physical model of dimensions (200mm*200mm) and (320) mm in height was constructed with raft foundation of (10) mm thickness for flexible raft and (23) mm for rigid raft made of reinforced concrete. To imitate the seismic excitation shaking table skill was applied, the shaker was adjusted to three frequencies equal to (1Hz,2Hz, and 3Hz) and displacement magnitude of (13) mm, the foundation was located at four different embedment depths (0,0.25B = 50mm,0.5B = 100mm, and B = 200mm), where B is the raft width. Generally, the maximum bending moment decreased with increasing the embedment depth from zero to B, by (75%,41%, and 43%) for the flexible raft under (1, 2 and 3) Hz respectively, for the rigid raft the maximum bending moment decreased by (62%, and 37%) under (1and 2) Hz respectively, for 3Hz excitation frequency, the direction of behavior wasn't the same for the case of the rigid raft foundation as the maximum bending moment increased with increasing the embedment depth from zero to (0.25B,0.5B and B) by (142% , 268% and 5%) compared with the surface raft foundation.

scholarly journals Experimental Behavior of Existing RC Columns Strengthened with HPFRC Jacket under Concentric and Eccentric Compressive Load

Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 521
Author(s):  
Paolino Cassese ◽  
Costantino Menna ◽  
Antonio Occhiuzzi ◽  
Domenico Asprone
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
High Performance ◽  
Compressive Load ◽  
Bending Moment ◽  
Critical Issue ◽  
Fiber Reinforced Concrete ◽  
Rc Columns ◽  
Rc Structures ◽  
Rc Building

Reinforced concrete (RC) structures built before the 1970 represent a large portion of the existing European buildings stock. Their obsolescence in terms of design criteria, materials, and functionality is becoming a critical issue for guaranteeing adequate compliance with current structural codes. Recently, a new jacketing system based on the use of high-performance fiber-reinforced concrete (HPFRC) has been introduced for strengthening existing RC building members. Despite the promising aspects of the HPFRC jacketing technique, currently, a comprehensive and systematic technical framework for its implementation is still missing. In this paper, the experimental performance of RC columns strengthened with the HPFRC jacket subjected to pure axial load and combined axial load-bending moment uncoupled from shear is investigated. The test outcomes confirmed a significant improvement of the structural performance for the strengthened columns, especially for higher values of eccentricity. Finally, a standard-based practice-oriented analytical tool for designing retrofit interventions using the HPFRC jacket is proposed. The comparison between the calculated and experimental results revealed a satisfactory prediction capability.

Time-Variant Reliability of RC Structures

2016 ◽  
Vol 847 ◽  
pp. 407-414
Author(s):  
Bruno Palazzo ◽  
Paolo Castaldo ◽  
Alessio Mariniello
Keyword(s):  
Reinforced Concrete ◽  
Probabilistic Approach ◽  
Bending Moment ◽  
Structural Safety ◽  
Time Variability ◽  
Structural Element ◽  
Rc Structures ◽  
Geometrical Properties ◽  
Proposed Model ◽  
Strength And Stiffness

Reinforced concrete structures are generally affected by degradation phenomena, which results in a time variability in strength and stiffness beyond the baseline conditions which are assumed in structural design, in particular when the concrete is exposed to an aggressive environment. Therefore, structural safety should realistically be considered time-variant. This paper provides a probabilistic approach to predict the time-evolution of the mechanical and geometrical properties of a reinforced concrete structural element (i.e., bridge pier) subjected to corrosion-induced deterioration, due to diffusive attack of chlorides, in order to evaluate its service life. The proposed model is based on Monte Carlo simulations in order to evaluate time variant axial force-bending moment resistance domains, with the aim to estimate the time-variant reliability index. Finally, an application to estimate the expected lifetime of a deteriorating reinforced concrete bridge pile is proposed.

Developing Reinforced Concrete Elastic-Plastic Beam Element Model

2006 ◽  
Vol 306-308 ◽  
pp. 535-540 ◽  
Author(s):  
Li Zhang ◽  
Zhan Li Liu ◽  
Zhuo Zhuang ◽  
T. Kanayama
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Conceptual Models ◽  
Element Model ◽  
Reinforced Concrete Beam ◽  
Beam Element ◽  
Response Analysis ◽  
Linear Section ◽  
Rc Structures ◽  
Elastic Plastic

The response analysis of reinforced concrete (RC) structures subjected to strong earthquake motions require realistic conceptual models. The special models, such as Clough and Takeda, which describe the non-linear section characteristic of reinforced concrete beam and column. In the earthquake motions, the deforming is sensitive to the response of structures intensively. The traditional lumped plastic model inevitably induces inaccuracy. Hence, meshing the members or distributing stiffness along the whole member is employed to simulate the seismic response of the structures. In this paper, Takeda elastic-plastic beam element model has been developed, which is based on general FEM code ABAQUS in order to simulate the response of RC. The influence is discussed due to the different lengths of plastic zone and element sizes.

Introduction and State-of-the-Art Review of Optimum Design of Reinforced Concrete Structures

2020 ◽  
pp. 1-35
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Behavior ◽  
Shear Walls ◽  
Reinforced Concrete Structures ◽  
Design Constraints ◽  
Rc Structures ◽  
Analysis And Design ◽  
Metaheuristic Methods ◽  
Review Study ◽  
Design Factors

This first chapter of the book presents an introduction and review study. The necessity of optimization in engineering design is discussed. The nonlinear behavior of problems plays an important role in the usage of metaheuristic methods because of complexity resulting from design constraints considering safety and utilization rules. Design factors in analysis and design of structures are given. A brief history about optimization of structures is presented, including the first early attempts of Galilei Galileo. As the main scope of the book, the review of studies considering optimization of reinforced concrete (RC) structures and members via metaheuristic methods are given. The optimized RC members include beams, columns, slabs, frames, bridges, footings, shear walls, retaining walls, and cylindrical walls.

Discrimination of Acoustic Emission Signals for Damage Assessment in a Reinforced Concrete Slab Subjected to Seismic Simulations

2013 ◽  
Vol 38 (3) ◽  
pp. 303-310 ◽  
Author(s):  
Francisco A. Sagasta ◽  
Juan L. Torné ◽  
Antonio Sánchez-Parejo ◽  
Antolino Gallego
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Mechanical Energy ◽  
Low Frequency ◽  
Shaking Table ◽  
Reinforced Concrete Slab ◽  
Rc Structures ◽  
Steel Columns ◽  
Ae Signals

Abstract The purpose of this work is to distinguish between Acoustic Emission (AE) signals coming from mechanical friction and AE signals coming from concrete cracking, recorded during fourteen seismic simulations conducted with the shaking table of the University of Granada on a reinforced concrete slab supported on four steel columns. To this end, a particular criterion is established based on the Root Mean Square of the AE waveforms calculated in two different temporal windows. This criterion includes a parameter calculated by optimizing the correlation between the mechanical energy dissipated by the specimen (calculated by means of measurements with accelerometers and displacement transducers) and the energy obtained from the AE signals recorded by low-frequency piezoelectric sensors located on the specimen. The final goal of this project, initiated four years ago, is to provide a reliable evaluation of the level of damage of Reinforced Concrete specimens by means of AE signals to be used in future Structural Health Monitoring strategies involving RC structures.

Optimum Design of Reinforced Concrete Beams

2020 ◽  
pp. 71-91
Keyword(s):  
Reinforced Concrete ◽  
Optimum Design ◽  
Nonlinear Behavior ◽  
Optimization Method ◽  
Reinforced Concrete Beams ◽  
Metaheuristic Algorithms ◽  
Rc Beam ◽  
Rc Structures ◽  
Eurocode 2 ◽  
The Cost

The design of reinforced concrete (RC) beams need special conditions to provide a ductile design. In this design, the maximum amount of tensile reinforcement must be limited to singly reinforced design. After the singly reinforced limit, the cost of doubly reinforced RC beam rapidly increases, and it may not be an optimum design. To consider this nonlinear behavior and other rules used in RC structures according to regulations such as ACI 318: Building code requirements for structural concrete and Eurocode 2: Design of concrete structures, an algorithmic and iteration optimization method is needed. In this chapter, two examples are presented, and optimum results are shared for methodologies employing several metaheuristic algorithms. The importance of using metaheuristic algorithms can be seen in this chapter.

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