Hi Sushil Kunwar

In the Abaqus software, the '*concrete failure' option in the concrete damage plasticity model defines a criterion for concrete failure. Adding this option enables the software to simulate the failure point of concrete under load, aiding in a more precise analysis of the structure's failure behavior, including element deletion and stress redistribution. Without this option, the model may overestimate the structural strength, as it lacks a specific definition for the failure point, which could lead to less safe design outcomes. Therefore, the choice of using or not using this feature depends on the aspects you wish to simulate and analyze regarding concrete behavior.

In Abaqus software, a concrete failure point typically refers to the point at which the material model representing concrete reaches a state of failure or damage. Abaqus is a finite element analysis (FEA) software commonly used for simulating and analyzing complex engineering problems, including the behavior of structures and materials under various conditions. Concrete is a brittle material, and its failure can be characterized by different failure criteria, such as: Compression Failure: This occurs when the concrete is subjected to high compressive stresses, leading to crushing or cracking. Abaqus can simulate this failure using appropriate material models and failure criteria for concrete under compression. Tensile Failure: Concrete is weak in tension, and Abaqus can simulate the initiation and propagation of cracks under tensile loading. Shear Failure: Concrete can also fail in shear, especially in regions where there is a combination of compression and shear stresses. Abaqus allows for modeling shear failure using appropriate material models and failure criteria. Combined Modes of Failure: Abaqus supports modeling the interaction of different failure modes, considering the complex behavior of concrete structures under various loading conditions. To define a concrete failure point in Abaqus, you need to choose an appropriate material model for concrete and specify the failure criteria and parameters associated with the selected model. Abaqus provides several concrete material models, such as the Concrete Damage Plasticity (CDP) model, the Concrete Damaged Plasticity (CDP) model, and others, each with its own set of parameters to define the material behavior and failure.

In Abaqus, the *concrete failure option is used in conjunction with the concrete damage plasticity model to define the initiation of cracking and failure in concrete elements. When this option is included in the input file, it allows you to specify a concrete failure criterion that controls when and how cracking and damage occur in the material.

If you choose not to include the *concrete failure option, the concrete damage plasticity model will still be active, but the initiation of cracking and failure will be governed by default settings or assumptions. The default behavior might not be suitable for all situations, and including the *concrete failure option provides more control over the failure criteria.

The *concrete failure option typically involves specifying parameters related to the concrete tensile and compressive strengths, fracture energy, and other material properties. By defining these parameters, you can tailor the behavior of the concrete damage plasticity model to better match the specific characteristics of your material and the failure criteria you are interested in.

The inclusion of the *concrete failure option can indeed affect the simulation results, not only in terms of visualization but also in terms of the calculated stresses, strains, and other output quantities. The choice of failure criteria and parameters can significantly impact the prediction of concrete cracking, damage evolution, and overall structural response.

If element deletion is also part of your simulation (presumably through the *element deletion option), it means that elements can be deleted once certain failure criteria are met. This can significantly influence the structural response, especially if you are interested in capturing the post-failure behavior or progressive collapse of a structure.

In summary, including the *concrete failure option in Abaqus provides you with more control over how concrete cracking and failure are simulated, allowing you to tailor the model to better represent the behavior of your specific material. However, it requires careful consideration of the parameters and their influence on the simulation results. If you choose not to include it, Abaqus will use default settings, but these might not be suitable for all cases.