scholarly journals Numerically Evaluation of FRP-Strengthened Members under Dynamic Impact Loading

Buildings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Faham Tahmasebinia ◽  
Linda Zhang ◽  
Sangwoo Park ◽  
Samad Sepasgozar
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Experimental Testing ◽  
Steel Tube ◽  
Dissipated Energy ◽  
Structural Behaviour ◽  
Concrete Members ◽  
Reinforced Concrete Slabs ◽  
Maximum Impact Force ◽  
The Impact

Reinforced concrete (RC) members in critical structures, such as bridge piers, high-rise buildings, and offshore facilities, are vulnerable to impact loads throughout their service life. For example, vehicle collisions, accidental loading, or unpredicted attacks could occur. The numerical models presented in this paper are shown to adequately replicate the impact behaviour and damage process of fibre-reinforced polymer (FRP)-strengthened concrete-filled steel tube (CFST) columns and Reinforced Concrete slabs. Validated models are developed using Abaqus/Explicit by reproducing the results obtained from experimental testing on bare CFST and RC slab members. Parameters relating to the FRP and material components are investigated to determine the influence on structural behaviour. The innovative method of using the dissipated energy approach for structural evaluation provides an assessment of the effective use of FRP and material properties to enhance the dynamic response. The outcome of the evaluation, including the geometrical, material, and contact properties modelling, shows that there is an agreement between the numerical and experimental behaviour of the selected concrete members. The experimentation shows that the calibration of the models is a crucial task, which was considered and resulted in matching the force–displacement behaviour and achieving the same maximum impact force and displacement values. Different novel and complicated Finite Element Models were comprehensively developed. The developed numerical models could precisely predict both local and global structural responses in the different reinforced concrete members. The application of the current numerical techniques can be extended to design structural members where there are no reliable practical guidelines on both national and international levels.

Experimental behaviour of hollow reinforced concrete members with inner octagonal steel tube under lateral impact

2019 ◽  
Vol 22 (15) ◽  
pp. 3328-3340
Author(s):  
Hui Zhao ◽  
Rui Wang ◽  
Chuanchuan Hou ◽  
Dongjie Zhang
Keyword(s):  
Reinforced Concrete ◽  
Load Ratio ◽  
Steel Tube ◽  
Lateral Impact ◽  
Low Velocity ◽  
Impact Performance ◽  
Failure Patterns ◽  
Concrete Members ◽  
Axial Load Ratio ◽  
The Impact

This work investigated the impact performance of hollow reinforced concrete members with inner octagonal steel tube. Experiments on 13 specimens subjected to low-velocity drop weight impact are presented in this article, covering key parameters such as the impact height, boundary condition, axial load ratio and thickness of the inner tube. The dynamic processes, failure patterns, impact force and mid-span deflection histories, and residual mid-span deflections were obtained from the experiments. Flexure-shear was observed as the main failure pattern for all the specimens under impact. It was found that all the key parameters considered had influences on the impact performance of hollow reinforced concrete specimens with inner octagonal steel tube. Effects of these parameters on the impact performance of hollow reinforced concrete members were discussed.

Flexural Capacity Study on Square Tube Filled with Steel Reinforced Concrete Members

2010 ◽  
Vol 163-167 ◽  
pp. 1574-1577 ◽  
Author(s):  
Tong Feng Zhao ◽  
Hong Nan Li ◽  
Jia Huan Yu
Keyword(s):  
Reinforced Concrete ◽  
Steel Tube ◽  
Flexural Capacity ◽  
Steel Reinforced Concrete ◽  
Deformation Curves ◽  
Concrete Members ◽  
Bending Load ◽  
Square Steel Tube ◽  
Abaqus Software

Moment-deformation curves of square steel tube filled with steel reinforced concrete subjected to bending load were simulated by the ABAQUS software. Calculated and experimental curves agreed well with each other. Through studying further the calculated member, the behavior of materials subjected to moment is given. Finally, flexural capacity formula of square steel tube filled with cross steel reinforced concrete is proposed.

Structural behaviour of FRP reinforced concrete slabs in fire

2020 ◽  
Vol 221 ◽  
pp. 111058 ◽  
Author(s):  
Antonio Bilotta ◽  
Alberto Compagnone ◽  
Laura Esposito ◽  
Emidio Nigro
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Reinforced Concrete Slabs ◽  
In Fire

Applicability of Sub-Modelling Technique for Dynamic Analysis of Concrete Structures With Attached Equipment Under Missile Impact

2020 ◽  
Author(s):  
Genadijs Sagals ◽  
Nebojsa Orbovic ◽  
Thambiayah Nitheanandan
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Behaviour ◽  
Modelling Technique ◽  
Research Centre ◽  
Front Wall ◽  
Fe Model ◽  
Reinforced Concrete Slabs ◽  
Rc Structure ◽  
Impact Area ◽  
The Impact

Abstract This paper describes the work conducted by the Canadian Nuclear Safety Commission (CNSC) related to the numerical simulations of reinforced concrete (RC) structures under deformable missile impact. The current paper is a continuation of the work conducted in the frame of the OECD/NEA* IRIS (Improving Robustness Assessment Methodologies for Structures Impacted by Missiles) Phase 3 benchmark project. The concrete mock-up with two simple structures attached, one welded and another bolted, was built and tested at the VTT Technical Research Centre in Espoo, Finland. This mock-up was impacted by three subsequent missiles with varying velocities in order to obtain the damage accumulation. To examine vibration transmission through the mock-up, the simple structures modelling equipment were attached to the rear wall of the structure, while the missile impact was at the centre of the front wall. The parameters of the missiles and the RC structure were selected to ensure a flexible behaviour of the RC target in the impact area with only moderate damages, specifically cracking and permanent deformation without perforation. The non-linear dynamic behaviour of the reinforced concrete slabs under missile impact was analyzed using the commercial FE code LS-DYNA. A hybrid FE model using both 3-D solid and 2-D shell FE models was developed for the target discretization. Since the ultimate objective of this work is to model the entire structure over long time periods, a simplified combined shell-solid model with distributed (smeared) reinforcement was selected and validated. This model employs solid FE around an impact area and shell FE for the rest of the mock-up. Detailed modelling of a large RC structure with all equipment attached leads to a very large finite element (FE) model. Therefore, two-level FE modelling using sub-modelling approach was employed: first, analyze the vibrations of a reinforced concrete structure with simplified equipment modelling, and second, analyze in detail the equipment connected to it. This approach assumes uncoupled dynamic behaviour of the structure and the equipment. While the sub-modelling technique is commonly used in static analysis, a special sensitivity analysis was conducted to prove the applicability of sub-modelling for impact analysis. Finally, the effect of structural damping was examined and the best possible damping was selected. The selected damping values and sub-models resulted in relatively good agreement with the test results for both global (RC mock-up) and local (equipment) behaviour.

THE EFFECT OF IMPACT LOADS ON PRESTRESSED CONCRETE SLABS

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Youmn Al Rawi ◽  
Yehya Temsah ◽  
Hassan Ghanem ◽  
Ali Jahami ◽  
Mohamad Elani
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Impact Loading ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Shear Mode ◽  
Reinforced Concrete Slab ◽  
Finite Element Program ◽  
Reinforced Concrete Slabs ◽  
The Impact

Many research studies have been conducted on the effect of impact loading on structures, and design procedures were proposed for reinforced concrete (RC) slabs; however the availability of these studies and procedures are limited for prestressed slabs. The proposed research will examine, using numerical analysis, the impact of rock fall on prestressed concrete slabs with equivalent moment capacity reinforced concrete slabs. It is expected that prestressed concrete slabs will have different behavior to resist impact loading compared with traditional reinforced concrete slabs. The thickness of the prestressed concrete slab will be 25cm whereas that of the reinforced concrete slab will be 30cm. The impact loading consists of 500Kg drop weight. The drop height will be 10m, 15m and 20m.The structural analysis is performed using a Finite Element program "ABAQUS". A comparison will be done between both slab types in terms of failure mode, damage, and deflection. It has been found that both slabs failed in punching. However, the RC slab performed better than the prestressed concrete slab with respect to the value of the deflection at mid-span, while both showed punching shear mode of failure.

BEHAVIOR OF REINFORCED CONCRETE SLABS UNDER ACCIDENTAL IMPACTS

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Shamsoon Fareed
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Concrete Slab ◽  
High Mass ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs ◽  
Numerical Predictions ◽  
Operational Life ◽  
The Impact

Loads resulting from activities such as rock fall, heavy drop weights (for e.g. equipment's, heavy machines during installation), missile and aircraft interaction with slabs may results in loading intensity which have higher magnitude as compared to static loading. Based on the velocity of the impacting object at the time of contact, these activities may result in impact loading. Therefore, slabs designed should provide resistance to these accidental loading during their entire operational life. In this study, a dynamic non-linear finite element analyses were conducted to investigate the behavior of the reinforced concrete slabs subjected to high-mass low-velocity impacts. For this purpose, initially an already published impact test results were used to validate the numerical predictions. Following validation, a study was conducted to investigate the influence of the impact velocity on the behavior of the reinforced concrete slab. Based on the numerical investigation, it was found that the velocity of the impacting object has a significant influence on the behavior exhibited by slab under impact loading. Furthermore, it was also found that the behavior of slab under impact is both local and global. Local behavior is associated with the damage caused at the contact area of the slab and the impactor, whereas global behavior refers to the overall deformation of the slab when stress waves move away from the impact zone and travel towards the supports.

Modelling the Response of Simply-Supported Two-Way Reinforced Concrete Slabs Exposed to Fire

2016 ◽  
Vol 711 ◽  
pp. 588-595
Author(s):  
Emran Baharudin ◽  
Luke Bisby ◽  
Tim Stratford
Keyword(s):  
Reinforced Concrete ◽  
Computational Study ◽  
Concrete Structures ◽  
Structural Response ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Fire Engineering ◽  
Reinforced Concrete Slabs ◽  
Structural Fire Engineering ◽  
Fire Codes

The historically good performance of concrete structures in real fires, and the lack of urgent drivers for the concrete industry to support research on the fire performance of concrete structures, means that research on the full frame response of concrete buildings to fires has received much less attention than for steel-framed structures. However, a credible understanding of, and ability to model, the response of concrete structures under fire exposure is crucial to make further progress in the field of structural fire engineering, and to make best use of the flexibility enabled by performance-based fire codes. This paper presents a computational study on the structural behaviour of reinforced concrete slabs during fire tests undertaken by Zhang et al.[16]. The distribution of stresses in the slabs is discussed, as is the need for further research to better understand structural response during fire. Amongst other factors, the assumed tensile strength of the concrete is crucial to accurately predict response. The results corroborate the existing consensus that concrete slabs in real buildings can, in some cases, withstand fires for longer than expected; this is due to mobilisation of membrane actions, amongst other factors.

scholarly journals Investigation on Structural Behavior of Bamboo Reinforced Concrete Slabs under Concentrated Load

2021 ◽  
Vol 50 (1) ◽  
pp. 227-238
Author(s):  
Yanuar Haryanto ◽  
Nanang Gunawan Wariyatno ◽  
Hsuan-Teh Hu ◽  
Ay Lie Han ◽  
Banu Ardi Hidayat
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Absorption Capacity ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Slabs ◽  
Cracking Pattern

Reinforced concrete is perhaps the most widely used building material in the world. However, the materials used for reinforcement of concrete i.e. steel is quite expensive and scarcely available in the developing world. As a result, bamboo is considered to be a cheaper replacement with high tensile strength. This research investigated the structural behaviour of bamboo-reinforced concrete slabs used for footplate foundation subjected to concentrated load. For this purpose, four different reinforced concrete slab panels were developed and analyzed. The influence of replacing steel with bamboo for the reinforcement of concrete slabs on their structural behaviour was assessed by determining the load-deflection characteristics, the ultimate load, the stiffness, the ductility, the cracking pattern, and the energy absorption capacity. The results showed that in comparison to steel reinforced concrete slabs, the strength of 82% can be acquired by the bamboo reinforced slabs. Furthermore, ductility demonstrated by the two types of specimens was almost equivalent i.e. up to 93%. Those indicated that the structural behaviour demonstrated by bamboo reinforced slabs is quite comparable to that of steel reinforced concrete slabs. Therefore, bamboo can prove to be a promising substitute for steel in concrete reinforcement. Future studies may further examine this opportunity.

scholarly journals Prediction of Punching Shear Capacity of Two-Ways FRP Reinforced Concrete Slabs

2017 ◽  
Vol 5 (2) ◽  
pp. 1-7
Author(s):  
Ilker Kara ◽  
Besian Sinani
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Design Standards ◽  
Concrete Members ◽  
Reinforced Concrete Slabs ◽  
Frp Reinforcement

An innovative solution to the corrosion problem is the use of fiber-reinforced polymer (FRP) as an alternative reinforcing material in concrete structures. In addition to the non corrodible nature of FRP materials, they also have a high strength-to-weight ratio that makes them attractive as reinforcement for concrete structures. Extensive research programs have been carried out to investigate the flexural behavior of concrete members reinforced with FRP reinforcement. On the other hand, the shear behavior of concrete members, especially punching shear of two-way slabs, reinforced with FRP bars has not yet been fully explored. The existing provisions for punching of slabs in most international design standards for reinforced concrete are based on tests of steel reinforced slabs. The elastic stiffness and bonding characteristics of FRP reinforcement are sufficiently different from those of steel to affect punching strength. In the present study, the equations of existing design standards for shear capacity of FRP reinforced concrete beams have been evaluated using the large database collected. The experimental punching shear strengths were compared with the available theoretical predictions, including the CSA S806 (CSA 2012), ACI-440.1R-15 (ACI 2015), BS 8110 (BSI 1997), JSCE (1997) a number of models proposed by some researchers in the literature. The existing design methods for FRP reinforced concrete slabs give conservative predictions for the specimens in the database. This paper also presents a simple yet improved model to calculate the punching shear capacity of FRPreinforced concrete slabs. The proposed model provides the accurate results in calculating the punching shear strengths of FRP-reinforced concrete slender slabs.

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