Nonlinear three–dimensional finite–element modelling of reinforced–concrete beams: Computational challenges and experimental validation

Question

1. What are the contributions in "Nonlinear three–dimensional finite–element modelling of reinforced–concrete beams: computational challenges and experimental validation" ?

2. What is the effect of the smeared crack approach on the crack?

3. What are the main methods of analysis of reinforced concrete?

4. What additional ingredients are needed to implement the discrete–crack approach?

Accepted Answer

The influence of the shape of the tension– softening law on the numerical load–deflection response was studied by considering bi–linear, exponential and linear post–failure stress–displacement and stress–strain relationships.. This is a non–obvious result that may be important to consider when studying the progressive collapse of RC structures.

Accepted Answer

In essence, the material stiffness in the direction of the principal tensile stress (i.e. orthogonal to the crack) at the cracking location is progressively reduced down to or close to zero.

Accepted Answer

The structural analysis of reinforced–concrete (RC) beams can be conducted with a greatvariety of methods, from simplified and well–established methods of RC design suggested in the codes of practice to other more sophisticated methods, which account for damage, plasticity, cracking, bond–slip interaction between steel rebars and concrete.

Accepted Answer

if the discrete–crack approach is used, two additional ingredients must be implemented, namely a crack initiation criterion and a bond–slip law at the steel–concrete interface.

Accepted Answer

In turn, an effective bond–slip law should consider a number of complex mechanisms, including but not limited to adhesion, friction, geometry of the ribs of the rebars, if any, localised concrete crushing and damage, and localised cracks.

Accepted Answer

This paper focuses on detailed nonlinear 3D FE simulations of RC beams using a smeared–crack model, namely the ‘concrete damaged–plasticity’ (CDP) model implemented in the commercial code ABAQUS (Dassault Systèmes 2014a), and an explicit–dynamics solution procedure.

Accepted Answer

As for the simulation of cracks in concrete, two approaches are normally used, thediscrete–crack approach and the smeared–crack approach.

Accepted Answer

Since this size is larger than or comparable with the dimensions of the majority of concrete structures, concrete should be treated as a quasi–brittle material, which requires nonlinear fracture–mechanics methods.

Accepted Answer

For this purpose, cohesive–zone models (CZMs) are typically used, which include the fictitious crack model (FCM) (Hillerborg, Modéer et al. 1976), the first CZM implemented in a FE analysis.

Accepted Answer

As for the steel rebars, monotonic tensile tests were performed on steel rebar specimens to determine the yield stress, which confirmed the value of the Young’s modulus as provided by the manufacturer.

Accepted Answer

Since this strengthening technique is not typically applied to the entire beam width, 3D effects can rise and the estimation of these effects and their impacts on the computed results become none–trivial.

Accepted Answer

On the contrary, the macroscopic approach, in which the principles of continuum mechanics are employed, is widely used to analyse a variety of concrete structures subjected to different types of loading.

Accepted Answer

The smeared–crack approach (Rashid 1968) treats cracked concrete as a continuousmedium, and approximates the discontinuity in the displacement field induced by cracks as localised inelastic strains, whose appearance and evolution are the result of the material nonlinear constitutive relationship.

Accepted Answer

One issue associated with the use of the smeared–crack concept is the tendency of inelasticstrains to localise along one row of finite–elements (Bažant 1976).

Accepted Answer

For ordinary applications, the complexities entailed by detailed three–dimensional (3D) numerical simulations may make the analysis too expensive in terms of time for setting up the model and obtaining the solution, cost of determining all material parameters and also level of knowledge and expertise required.

Accepted Answer

The concrete used to cast the two control beams was a mixture of basaltic sand, 10–mmaggregates and cement, with a 0.79 water/cement ratio.

Nonlinear three–dimensional finite–element modelling of reinforced–concrete beams: Computational challenges and experimental validation

Chat with Paper

AI Agents for this Paper

Most frequently asked questions

1. What are the contributions in "Nonlinear three–dimensional finite–element modelling of reinforced–concrete beams: computational challenges and experimental validation" ?

2. What is the effect of the smeared crack approach on the crack?

3. What are the main methods of analysis of reinforced concrete?

4. What additional ingredients are needed to implement the discrete–crack approach?

5. What is the role of the bond–slip law in a RC beam?

6. What is the main focus of this paper?

7. What is the common approach for the simulation of cracks in concrete?

8. What is the common reason for the size of the crack?

9. What is the common method used for the simulation of cracks in concrete?

10. What was the tensile strength of the steel rebars?

11. What is the main reason why the authors used 3D elements to model RC beams?

12. What is the common method of analysis of reinforced concrete?

13. What is the difference between the smeared and the rotating crack approach?

14. What is the problem with the smeared–crack approach?

15. What is the cost of a numerical analysis of reinforced concrete?

16. What was the ratio of basaltic sand and cement used to cast the two control?

Figures

Citations

Risk-based probabilistic assessment of a bridge collapse due to abutments scour. A case study

Finite Element Modelling of RC Beams Containing Recycled Aggregate Concrete Subjected to Pure Flexure Failure

Experimental Validation of Reinforced Concrete Beam Incorporating Coal Fly Ash and Coal Bottom Ash Using Numerical Analysis

Modelling Fibre-Reinforced Concrete for Predicting Optimal Mechanical Properties

Seismic fragility analysis of precast concrete framed structures with dry connections

References

Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements

Analysis of crack formation and crack growth in concrete by means of fracture mechanics and finite elements

Soil mechanics and plastic analysis or limit design

A plastic-damage model for concrete

Plastic-Damage Model for Cyclic Loading of Concrete Structures

Related Papers (5)

A plastic-damage model for concrete

Plastic-Damage Model for Cyclic Loading of Concrete Structures

Finite element analysis of punching shear of concrete slabs using damaged plasticity model in ABAQUS

Modelling of reinforced concrete structures and composite structures with concrete strength degradation taken into consideration

Element size effects in nonlinear analysis of reinforced concrete members