Comparative Study Of Extended Finite Element Method And Plastic Damage Model In The Modeling Of Localized Failure In Concrete

The performance of concrete with catastrophic crack is one of the key topics in civil engineering.Structures always suffer from cracks which is harmful for its entirety and bearing capacity,during the whole service life.The realistic modeling of crack opening process is conducive to optimizing design theory and evaluating structural safety.In this way,assessing the performance of those crack models is a prerequisite for improving the accuracy and the applicability.In this work,two typical kind of numerical approaches are investigated.More concretely,the well-known extended finite element method(XFEM)in discrete discontinuity family and the plastic damage model in the smeared crack approach are considered.Tensile cracking is one of the major contributor to the failure of concrete.Therefor some benchmark tests of concrete structures under tension dominant conditions,including mode-I failure and mixed mode failure test,are chosen to validate these two kind of crack model and to summarize the merits and demerits.According to the simulation results,including the responses of load versus displacement and crack patterns,it is found that the prediction of crack pattern is crucial to simulation results.For the plastic damage model,it is suffered from serious spurious mesh-bias dependency leading to pathological crack pattern as well as inaccurate global responses.For XFEM,it is of high coarse mesh approximate precision and also mesh-insensitive which guarantees the accuracy of the simulation results.However,the frequently adopted nonlocal maximum principal tensile stress criterion is sometimes invalid.