Comparative study of numerical methods used in prediction of post-crack behavior of waffle slabs

One effective way to reduce dead and earthquake loads isto use waffleslabs.The use of waffleslabsleads to smaller sections.There are various methods for predicting the behavior of slabs, the most important of which is fracturemechanics.Considering the varietyof geometry of waffleslabs, it is important to investigate the formation and growth of cracks in them.The current research aimsto analyze the post-crack behavior of waffleslabs under common loading conditions using the finite element method by using numerical modeling to analyze cracks in reinforced concrete members.by comparing the obtained results with the laboratory sample, the optimal numerical model for predicting the behavior of the hollow slab was determined.The waffleslab sample was modeled with two types of distributedand concentrated loading conditions and two types of simple and fixedsupport conditions.The models weremodeled by two methods of concrete damage plasticityand smeared cracked concreteby Abaqus software. Various parameters of these samples, including the load-displacement diagram, the load coincident with the formation of cracks, the displacement in the middle of the slab opening, and the pattern of the formation and propagationof cracks, etc., were discussed and investigated.To validate and control the modeling process, the laboratory results of the research of NithyambigaiG et al. in 2021 have been used.The outcomes of thisstudy showed; a relatively good correspondence between the two methods of Concrete damage plasticity and the concretesmeared crack model, but due to the definition of failure in the Concrete damage plasticity method, more accurate results can be obtained.