Nonlinear modelling and finite element analysis on the load-bearing capacity of RC beams with considering the bond–slip effect

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pandimani Pandimani ◽  
Markandeya Raju Ponnada ◽  
Yesuratnam Geddada

Purpose This paper aims to present nonlinear numerical simulations using the versatile finite element (FE) analysis tool ANSYS and theoretical analysis based on code provisions to assess the load-carrying capacity of reinforced concrete (RC) beams under two-point monotonic static loadings. Design/methodology/approach Four quarter-size FE models with load and geometry symmetry conditions were constructed, the load-bearing capacity and associated mid-span deflections at critical points are verified against the full-scale experimental RC beams available in the literature. These developed FE models incorporated the tension stiffening effects and bond–slip behaviour. Theoretical analyses based on Indian standard code IS: 456–2000 and ACI 318–19 were also carried to verify the experimental and numerical predicted moments at critical loading points. Findings The load-deflection curves predicted through FE models exhibit closer corroboration with the experimental curves throughout the loading history. The contour plots for deflections, concrete principal stresses, reinforcement yield stresses are satisfactorily predicted by the FE models, which reveal the complete information of nonlinear behaviour of RC beams. The developed model well captured the initial and progressive crack patterns at each load increments. Practical implications The FE modelling is an efficient, valid and economical tool that is an alternative to the expensive experimental program and can be used to explore, analyse and fully understand the nonlinear response of RC beams under static loadings. Originality/value The ultimate moment capacity evaluated based on ACI 318–19 code provision show a better correlation with the experimental data as compared to the IS: 456–2000 code provision. The ultimate loads and associated centre-span deflections predicted by RN-2, RN-3, RB-12 and RB-16 FE model show a discrepancy of 1.66 and –0.49%, –4.68 and –0.60%, –9.38 and –14.53% and –4.37 and 4.21%, respectively, against the experimental results, which reveals that the developed ANSYS FE models predict consistent results and achieved a reasonable agreement with the experimental data.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pandimani Pandimani ◽  
Markandeya Raju Ponnada ◽  
Yesuratnam Geddada

Purpose This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static load using the robust and reliable general-purpose finite element (FE) software ANSYS. A parametric study is carried out to analyse the flexural and ductility behaviour of RC beams under various influencing parameters. Design/methodology/approach To develop and validate the numerical FE models, a total of four experimentally tested simply supported RC beams are taken from the available literature and two beams are selected from each author. The concrete, steel reinforcements, bond-slip mechanism, loading and supporting plates are modelled using SOLID65, LINK180, COMBIN39 and SOLID185 elements, respectively. The validated models are then used to conduct parametric FE analysis to investigate the effect of concrete compressive strength, percentage of tensile reinforcement, compression reinforcement ratio, transverse shear reinforcement, bond-slip mechanism, concrete compressive stress-strain constitutive models, beam symmetry and varying overall depth of beam on the ultimate load-carrying capacity and ductility behaviour of RC beams. Findings The developed three-dimensional FE models can able to capture the load and midspan deflections at critical points, the accurate yield point of steel reinforcements, the formation of initial and progressive concrete crack patterns and the complete load-deflection curves of RC beams up to ultimate failure. From the numerical results, it can be concluded that the FE model considering the bond-slip effect with Thorenfeldt’s concrete compressive stress-strain model exhibits a better correlation with the experimental data. Originality/value The ultimate load and deflection results of validated FE models show a maximum deviation of less than 10% and 15%, respectively, as compared to the experimental results. The developed model is also capable of capturing concrete failure modes accurately. Overall, the FE analysis results were found quite acceptable and compared well with the experimental data at all loading stages. It is suggested that the proposed FE model is a practical and reliable tool for analyzing the flexural behaviour of RC members and can be used for performing parametric studies.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Long Liu ◽  
Lifeng Wang ◽  
Ziwang Xiao

PurposeReinforcement of reinforced concrete (RC) beams in-service have always been an important research field, anchoring steel plate in the bottom of the beams is a kind of common reinforcement methods. In actual engineering, the contribution of pavement layer to the bearing capacity of RC beams is often ignored, which underestimates the bearing capacity and stiffness of RC beams to a certain extent. The purpose of this paper is to study the effect of pavement layer on the RC beams before and after reinforcement.Design/methodology/approachFirst, static load experiments are carried out on three in-service RC hollow slab beams, meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Last, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.FindingsThe experimental results showed that pavement layers increase the flexural capacity of hollow slab beams by 16.7%, and contribute to increasing stiffness. Ductility ratio of SPRCB3 and PRCB2 was 30% and 24% lower than that of RCB1, respectively. The results showed that when the steel plate thickness was 1 mm–6 mm, the bearing capacity of the hollow slab beam increased gradually from 2158.0 kN.m to 2656.6 kN.m. As the steel plate thickness continuously increased to 8 mm, the ultimate bearing capacity increased to 2681.0 kN.m. The increased thickness did not cause difference to the bearing capacity, because of concrete crushing at the upper edge.Originality/valueIn this paper, based on the experimental study, the bearing capacity of hollow beam strengthened by steel plate with different thickness is extrapolated by finite element simulation, and its influence on ductility is discussed. This method not only guarantees the accuracy of the bearing capacity evaluation, but also does not require a large number of samples, and has certain economy. The research results provide a basis for the reinforcement design of similar bridges.


2019 ◽  
Vol 23 (6) ◽  
pp. 1074-1086 ◽  
Author(s):  
Tao Zhu ◽  
Hongjun Liang ◽  
Yiyan Lu ◽  
Weijie Li ◽  
Hong Zhang

This article investigates the behaviour of slender concrete-filled steel tube square columns strengthened by concrete-filled steel tube jacketing. The columns were realised by placing a square outer steel tube around the original slender concrete-filled steel tube column and pouring strengthening concrete into the gap between the inner and outer steel tubes. Three concrete-filled steel tube square columns and seven retrofitted columns ranging from 1200 to 2000 mm were tested to failure under axial compression. The experimental parameters included three length-to-width ( L/ B1) ratios, three width-to-thickness ( B1/ t1) ratios and three strengths of concrete jacket (C50-grade, C60-grade and C70-grade). Experimentally, the retrofitted columns failed in a similar manner to traditional slender concrete-filled steel tube columns. After strengthening, the retrofitted columns benefitted greatly from the component materials, with their load-bearing capacity and ductility notably enhanced. These enhancements were mainly brought about by sectional enlargement and good confinement of concrete. A finite element model was developed using ABAQUS to better understand the axial behaviour of the retrofitted specimens. A parametric study was conducted, with parameters including the length of the column, thickness of the outer steel tube, strength of the concrete jacket, yield strength of the outer steel tube, thickness of the inner steel tube and strength of the inner concrete. Furthermore, the finite element model was adopted to study the behaviour of rust-damaged and post-fire slender concrete-filled steel tube square columns strengthened by square concrete-filled steel tube jacketing. A modified formula was proposed to predict the load-bearing capacity of retrofitted specimens, and the numerical results agreed well with the experiments and the finite element results of undamaged, rust-damaged and post-fire specimens. It could be used as a reference for practical application.


2011 ◽  
Vol 311-313 ◽  
pp. 1941-1944
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo ◽  
Xiao Yan Sun

intermediate crack-induced debondingis one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to mitigateintermediate crack-induced debondingfailure.However, these models and provisions can not mitigate this failure mode effectively. Recnetly, new models have been proposed to solve this problem. Out of all the existing models, four typical ones are investigated in the current study. A comprehensivecomparison among these models is carried out in order to evaluate their performance and accuracy. Test results offlexural specimens with intermediate crack-induced debonding failurecollected from the existing literature are used in the current comparison. The effectivenessand accuracy of each model have been evaluated based on these experimental results. It is shown that the current modals are all conservative and inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.


2016 ◽  
Vol 8 (3) ◽  
pp. 85-93
Author(s):  
Andrej Mudrov ◽  
Gintas Šaučiuvėnas ◽  
Antanas Sapalas ◽  
Ivar Talvik

This article considers the calculation of load-bearing capacity of flange-plate joints with bolts along two sides of rectangular hollow sections (RHS) under axial tension. It provides a review and comparison of various calculation methodologies for establishing the load-bearing capacity of RHS flange-plate joints, such as suggested in EN 1993-1-8:2005 and STR 2.05.08:2005 as well as those proposed in different countries and by other authors. Common design principles and derived results for load-bearing capacity of flange-plate joints have been analysed and compared. Following the numerical modelling, which has been done using ANSYS Workbench finite element program, the derived results for load-bearing capacity have been compared with analytical load-bearing capacity results for flange-plate joints of the same structure. The analysis has focused on one type of flange-plate joints with bolts – both preloaded and non-preloaded – along two opposite sides of the tube, with the flange thickness of 15 mm and 25 mm.


2011 ◽  
Vol 341-342 ◽  
pp. 833-837
Author(s):  
Xun Wang ◽  
Qi Lin Zhang ◽  
Jun Chen ◽  
Zhi Xiong Tao ◽  
Jun Chen

Combining with load bearing capacity tests, the laminated glass simply supported on four sides subjected to bending is analyzed using the finite element software ANSYS. Based on the theoretical and experimental deflection results, the accurate calculation model is established. In order to calculate the deflection of laminated glass subjected to short-time loading such as wind load based on different codes, the equivalent thickness of laminated glass based on Chinese code 2003 and European code is calculated, respectively. Finally, on the basis of many finite element analyses, load bearing capacity tests and code values, the formulas for calculating maximum deflectiont of four-sides supported laminated glass is revised in “Technical code for glass curtain wall engineering” (China) and corresponding correction coefficient is given.


2018 ◽  
Vol 64 (4) ◽  
pp. 89-103
Author(s):  
A. Nesterenko ◽  
G. Stolpovskiy ◽  
M. Nesterenko

AbstractThe actual load-bearing capacity of elements of a building system can be calculated by dynamic parameters, in particular by resonant frequency and compliance. The prerequisites for solving such a problem by the finite element method (FEM) are presented in the article. First, modern vibration tests demonstrate high accuracy in determination of these parameters, which reflects reliability of the diagnosis. Secondly, most modern computational complexes do not include a functional for calculating the load-bearing capacity of an element according to the input values of resonance frequencies. Thirdly, FEM is the basis for development of software tools for automating the computation process. The article presents the method for calculating flexural stiffness and moment of inertia of a beam construction system by its own frequencies. The method includes calculation algorithm realizing the finite element method.


Author(s):  
MD Waquar Alam

Large displacements during excavation are regularly observed in Squeezing ground condition and Rock-burst condition with high overburden. The expected displacement has to be estimated prior to excavation to provide enough allowance for the displacements. The support system need to be well-suited through the estimated imposed strains. As the estimated displacements and thus the strains in the support depend upon the load-bearing capacity of support. The ratio of uniaxial compressive strength of rock mass to maximal insitu stress determines tunnel integrity in the weak region.This ratio estimates the requirements of initial lining to control strain to a stipulated level. The elasto-plastic theory may deliver definitive forecasts providing the strength limitations of rock masses are identified accurately. With the help of empirical analysis, the development of displacements for diverse advance rates and supports can be concluded. As a consequence, a quantitative finite element model based on an advanced built-in model is designed to analyse the load-bearing efficiency of initial lining although taking into consideration the time-dependent and non-linear material behaviour of initial lining. The time-dependent excavation mechanism of the drill-and-blast approach for tunnels guided by full face excavation is considered in the finite element model. The material parameters for the initial lining were computed based on case studies- (A Chibro-Khodri Hydropower Tunnel).


Sign in / Sign up

Export Citation Format

Share Document