scholarly journals A Numerical Study on the Performance of GFRP RC Beams Exposed to High Temperature

2020 ◽  
Vol 13 (2) ◽  
pp. 136-143
Author(s):  
Nuha Hussein Ali ◽  
Haitham Al-Thairy
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Numerical Model ◽  
Elevated Temperatures ◽  
Numerical Study ◽  
Reinforced Concrete Beams ◽  
Temperature History ◽  
Effect Of Temperature ◽  
Rc Beams ◽  
Finite Element Software

This paper presents and validates a numerical model utilizing the nonlinear finite element software ABAQUS/Standard to simulate the performance and failure of GFRP reinforced concrete beams under high temperature. A numerical model was firstly developed by selecting the proper geometrical and material modelling parameters with suitable analysis procedure available in ABAQUS/Standard. The developed numerical model was verified by comparing numerical results with the corresponding results of experimental test extracted from current study on GFRP-RC beams under different elevated temperatures ranges from (20 to 600ºC). Validation results have indicated the accuracy of the suggested numerical model. The validated numerical model was implemented to investigate the effect of important parameters on the performance and maximum load of GFRP-RC beams under different elevated temperatures that are not considered in the current experimental tests. These parameters include effect of exposed time or time- temperature history; effect of temperature distribution around the beams cross-section. Results indicate that the finite element software ABAQUS/Standard can reasonably predict the performance and ultimate load of GFRP-RC beams under different elevated temperatures.

Analytical Method of Temperature Prediction in Reinforced Concrete Beams

2014 ◽  
Vol 5 (4) ◽  
pp. 367-380 ◽  
Author(s):  
Muhammad Rafi ◽  
Ali Nadjai
Keyword(s):  
Reinforced Concrete ◽  
Analytical Method ◽  
Elevated Temperatures ◽  
Reinforced Concrete Beams ◽  
Temperature History ◽  
Rc Beams ◽  
Temperature Prediction ◽  
Computational Support ◽  
In Fire

The determination of temperature profile within a reinforced concrete (RC) beam is essential for carrying out structural analysis at elevated temperatures. The temperatures are usually estimated using sophisticated numerical techniques which require computational support. Since the determination of rebar temperature in RC beams is more important than the concrete temperature a reliable analytical method of temperature prediction can become a helpful tool in simple beam analysis problems which are employed for determining residual strength in fire. This paper presents the details of development of an empirical equation for the prediction of temperature of rebar in RC beams. The equation is also capable of predicting concrete temperatures at different locations within the beam. The predictions made by the equation were compared with the temperatures determined from experimental beam testing and finite element (FE) analysis. A good correlation of the predicted temperatures was found for the entire time-temperature history with both the observed data and the estimated temperatures by FE models.

scholarly journals Numerical Study on The Structural Behavior of RC Beams after Exposure to Elevated Temperature

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Sajida Kadhem Al-Jasmi ◽  
Haitham Al-Thairy
Keyword(s):  
Elevated Temperature ◽  
Numerical Model ◽  
Heating Rate ◽  
Parametric Study ◽  
Elevated Temperatures ◽  
Numerical Study ◽  
Beam Model ◽  
Rc Beam ◽  
Rc Beams ◽  
Study Results

This paper presents a numerical simulation of the structural response of reinforced concrete (RC) beams under elevated temperature using the commercial finite element package ABAQUS. A numerical model is firstly suggested by selecting the appropriate geometrical and material properties of the RC beam model at elevated temperature. Thereafter, the suggested numerical model was validated against the experimental tests conducted in this study. The validation results in terms of temperatures- time histories; load-mid span deflection of the RC beams have confirmed the accuracy of the suggested numerical model. The validated numerical model was implemented in conducting a parametric study to investigate the effects of two important parameters on the behavior and failure of RC beams under elevated temperature. These parameters are the effect of the high ranges of elevated temperatures; and the effect of heating rate. The parametric study results have revealed that the failure load and the ductility of RC beams under elevated temperature are not considerably influenced by changing the heating rate. It has also been concluded that the ultimate load capacities of RC beams have considerably decreased by 55.49%, 74.72%, and 81.31% comparing with the control RC beam when they exposed to temperature values of 600 ºC, 700 ºC, and 800ºC respectively. These conclusions may be used in the design of RC beams subjected to fire induced temperature. Numerical model

scholarly journals Dynamic Properties of Cortical Bone Tissue: Impact Tests and Numerical Study

2011 ◽  
Vol 70 ◽  
pp. 387-392
Author(s):  
Adel A. Abdel-Wahab ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Cortical Bone ◽  
Bone Tissue ◽  
Impact Loading ◽  
Numerical Study ◽  
Numerical Models ◽  
Dynamic Properties ◽  
High Energy ◽  
Finite Element Software

Bone is the principal structural component of a skeleton: it assists the load-bearing framework of a living body. Structural integrity of this component is important; understanding of its mechanical behaviour up to failure is necessary for prevention and diagnostic of trauma. Bone fractures occur in both low-energy trauma, such as falls and sports injury, and high-energy trauma, such as car crash and cycling accidents. By developing adequate numerical models to predict and describe the deformation and fracture behaviour up to fracture of a cortical bone tissue, a detailed study of reasons for, and ways to prevent or treatment methods of, bone fracture could be implemented. This study deals with both experimental analysis and numerical simulations of this tissue and its response to impact dynamic loading. Two areas are covered: Izod tests for quantifying a bone’s behaviour under impact loading, and a 3D finite-element model simulating these tests. In the first part, properties of cortical bone tissue were investigated under impact loading condition. In the second part, a 3D numerical model for the Izod test was developed using the Abaqus/Explicit finite-element software. Bone has time-dependent properties – viscoelastic – that were assigned to the specimen to simulate the short term event, impact. The developed numerical model was capable of capturing the behaviour of the hammer-specimen interaction correctly. A good agreement between the experimental and numerical data was found.

scholarly journals Study on the Optimal Prestress Level of RC Beams Reinforced with SMA Bars

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zeying Yang ◽  
Zhengquan Cheng ◽  
Tianmin Wang ◽  
Yinglin Sun ◽  
Chenghe Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Finite Element Software ◽  
Element Simulation ◽  
Shear Performance ◽  
Simulation Results

In order to study the optimal prestress level of RC (reinforced concrete) beams strengthened by SMA bars, the finite element software ABAQUS was used to numerically simulate the shear performance of RC beams strengthened by SMA bars with different prestress levels. By using the finite element software ABAQUS, the model of RC beams strengthened by SMA bars with different prestressing levels was established. The influence of SMA bars with different prestressing levels on the shear capacity of RC beams was analyzed from the aspects of stress, strain, load, deflection, and maximum bearing capacity, and the failure types and failure processes of RC beams strengthened with different prestressing levels were obtained. Comparing the numerical simulation results with the experimental results, it is found that the error between the finite element simulation results and the experimental results is less than 10%.

scholarly journals Modeling of Reinforced Concrete Beams Exposed to Fire by Using a Spectral Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Rui Sun ◽  
Bo Xie ◽  
Ricardo Perera ◽  
Yongjun Pan
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Elevated Temperatures ◽  
Mechanical Response ◽  
Numerical Procedure ◽  
Reinforced Concrete Beams ◽  
Fe Model ◽  
Rc Beams ◽  
Dimensional Finite Element ◽  
Different Levels

This paper presents a numerical procedure for predicting the mechanical behavior of reinforced concrete (RC) beams exposed to fire. Thermal behavior is captured using a two-dimensional finite element (FE) model in an environment of elevated temperatures, while a one-dimensional spectral numerical model is formulated to simulate the mechanical response of the beam under increasing loads. Both models are integrated. Previous thermal results obtained from the FE model are provided for the proposed numerical model to calculate the responses of the RC beam for different levels of fire exposure. Few elements are deployed in this study due to the simplicity and efficiency of the proposed numerical model. Consequently, the computational burden of the numerical simulation for predicting the structural performances of RC beams exposed to fire is released comparing with conventional FE model. The numerical results are consistent with the test data, which demonstrate the model’s capability of efficiently simulating the thermomechanical behaviors of RC beams due to its simplicity and accuracy.

scholarly journals Numerical model of the nanoindentation test based on the digital material representation of the Ti/TiN multilayers

2015 ◽  
Vol 33 (2) ◽  
pp. 348-355 ◽  
Author(s):  
Konrad Perzyński ◽  
Radosław Wiatr ◽  
Łukasz Madej
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Cellular Automata ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Nanoindentation Test ◽  
Cellular Automata Model ◽  
Finite Element Software ◽  
Specific Morphology ◽  
Digital Material

AbstractThe developed numerical model of a local nanoindentation test, based on the digital material representation (DMR) concept, has been presented within the paper. First, an efficient algorithm describing the pulsed laser deposition (PLD) process was proposed to realistically recreate the specific morphology of a nanolayered material in an explicit manner. The nanolayered Ti/TiN composite was selected for the investigation. Details of the developed cellular automata model of the PLD process were presented and discussed. Then, the Ti/TiN DMR was incorporated into the finite element software and numerical model of the nanoindentation test was established. Finally, examples of obtained results presenting capabilities of the proposed approach were highlighted.

scholarly journals Gradient Nonlocal Enhanced Microprestress-Solidification Theory and Its Finite Element Implementation

2021 ◽  
Vol 8 ◽  
Author(s):  
Teng Tong ◽  
Changqing Du ◽  
Xiaofan Liu ◽  
Siqi Yuan ◽  
Zhao Liu
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Deformation Gradient ◽  
Damage Model ◽  
Reinforced Concrete Beams ◽  
Chain Model ◽  
Finite Element Software ◽  
Order Deformation ◽  
Implicit Solver

Time-dependent responses of cracked concrete structures are complex, due to the intertwined effects between creep, shrinkage, and cracking. There still lacks an effective numerical model to accurately predict their nonlinear long-term deflections. To this end, a computational framework is constructed, of which the aforementioned intertwined effects are properly treated. The model inherits merits of gradient-enhanced damage (GED) model and microprestress-solidification (MPS) theory. By incorporating higher order deformation gradient, the proposed GED-MPS model circumvents damage localization and mesh-sensitive problems encountered in classical continuum damage theory. Moreover, the model reflects creep and shrinkage of concrete with respect to underlying moisture transport and heat transfer. Residing on the Kelvin chain model, rate-type creep formulation works fully compatible with the gradient nonlocal damage model. 1-D illustration of the model reveals that the model could regularize mesh-sensitivity of nonlinear concrete creep affected by cracking. Furthermore, the model depicts long-term deflections and cracking evolutions of simply-supported reinforced concrete beams in an agreed manner. It is noteworthy that the gradient nonlocal enhanced microprestress-solidification theory is implemented in the general finite element software Abaqus/Standard with the implicit solver, which renders the model suitable for large-scale creep-sensitive structures.

scholarly journals Verification of the flexion and shear behavior in masonry panels accordance to ABNT NBR 15961-1 (2011), EN 1996-1-1 (2005) and ACI TMS 530 (2013)

2018 ◽  
Vol 11 (4) ◽  
pp. 673-685
Author(s):  
R. C. MATA ◽  
C. S. RAMOS ◽  
M. L. C. SILVA
Keyword(s):  
Computer Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Design Criteria ◽  
Two Dimensional ◽  
Finite Element Software ◽  
Modelling Procedure ◽  
Increasing Trend ◽  
American Standard ◽  
Compression Level

Abstract This paper presents a numerical analysis of the mechanical behavior of structural masonry panels submitted to horizontal and vertical stresses. To evaluate the design process of these structures, the results obtained by the computer simulations were compared with the results determined by the design criteria of ABNT NBR 15961-1 (2011), ACI TMS 530 (2013) and EN 1996-1-1 (2005). The finite element software DIANA v.9.3 was used to simulate two-dimensional models with the simplified micro modelling procedure. The results obtained by the normative standards were more conservative than the results of the numerical model, as expected. With the increase of the pre-compression level, the computer simulation has demonstrated the increasing trend of the values of resistant forces, besides the change of the way of rupture of the panels. Among the three standards evaluated, the American Standard was the most conservative.

Creative Design-by-Analysis Solutions Applied to High-Temperature Components

1993 ◽  
Vol 115 (3) ◽  
pp. 221-227
Author(s):  
A. K. Dhalla
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Detailed Analysis ◽  
Structural Response ◽  
Cost Effective ◽  
Element Analysis ◽  
Finite Element Software ◽  
Division 1 ◽  
High Temperature Components ◽  
Elevated Temperature Design

Elevated temperature design has evolved over the last two decades from design-by-formula philosophy of the ASME Boiler and Pressure Vessel Code, Sections I and VIII (Division 1), to the design-by-analysis philosophy of Section III, Code Case N-47. The benefits of design-by-analysis procedures, which were developed under a US-DOE-sponsored high-temperature structural design (HTSD) program, are illustrated in the paper through five design examples taken from two U.S. liquid metal reactor (LMR) plants. Emphasis in the paper is placed upon the use of a detailed, nonlinear finite element analysis method to understand the structural response and to suggest design optimization so as to comply with Code Case N-47 criteria. A detailed analysis is cost-effective, if selectively used, to qualify an LMR component for service when long-lead-time structural forgings, procured based upon simplified preliminary analysis, do not meet the design criteria, or the operational loads are increased after the components have been fabricated. In the future, the overall costs of a detailed analysis will be reduced even further with the availability of finite element software used on workstations or PCs.

Performance and Reliability of MEMS Gyroscopes and Packaging at High Temperatures

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000359-000366 ◽  
Author(s):  
Patrick McCluskey ◽  
Chandradip Patel ◽  
David Lemus
Keyword(s):  
High Temperature ◽  
Indoor Environment ◽  
Elevated Temperatures ◽  
High Sensitivity ◽  
Effect Of Temperature ◽  
Gps Tracking ◽  
Mems Gyroscope ◽  
Mems Gyroscopes ◽  
Gyroscope Sensor

Elevated temperatures can significantly affect the performance and reliability of MEMS gyroscope sensors. A MEMS vibrating resonant gyroscope measures angular velocity via a displacement measurement which can be on the order on nanometers. High sensitivity to small changes in displacement causes the MEMS Gyroscope sensor to be strongly affected by changes in temperature which can affect the displacement of the sensor due to thermal expansion and thermomechanical stresses. Analyzing the effect of temperature on MEMS gyroscope sensor measurements is essential in mission critical high temperature applications, such as inertial tracking of the movement of a fire fighter in a smoke filled indoor environment where GPS tracking is not possible. In this paper, we will discuss the development of the high temperature package for the tracking application, including the characterization of the temperature effects on the performance of a MEMS gyroscope. Both stationary and rotary tests were performed at room and at elevated temperatures on 10 individual single axis MEMS gyroscope sensors.

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