Structural Engineering Research Centre

About: Structural Engineering Research Centre is a facility organization based out in Chennai, India. It is known for research contribution in the topics: Finite element method & Fracture mechanics. The organization has 520 authors who have published 703 publications receiving 7298 citations.

Handling Uncertainties in Knowledge Modeling and Acquisition for the Development of a Knowledge‐Based System

Abstract: Knowledge acquisition is perhaps the most important phase in the development of knowledge-based systems (KBSs). Problems associated with knowledge acquisition include creating an explicit model of handling uncertainty for solving models in a complex domain. This article illustrates how knowledge modeling facilitates the acquisition of knowledge that is vague and uncertain. A hierarchical model is adopted for knowledge acquisition. The domain of the problem, i.e., damage assessment and vulnerability analysis of structures subjected to cyclones, is characterized by the presence of uncertainties in various forms. A KBS based on the hierarchical knowledge model has been developed that has the flexibility to handle the uncertainties using probabilistic and fuzzy set approaches depending on the nature of uncertainty. The hierarchical model for handling complexities and uncertainties in knowledge, the knowledge-acquisition strategy, the inference mechanism, and the representation used are described. Two typical sessions, one for damage assessment and another for vulnerability analysis, are presented to demonstrate the working of the KBS and its efficacy in handling uncertain information.

Modelling of RC Beams Strengthened with Basalt Reinforced Concrete

Abstract: An analytical model was developed to predict the response behaviour of RC beam strengthened with basalt reinforced concrete. The model was based on the internal forces, strains, and stresses in the cross- section of the strengthened composite beam. It is observed that the analytical results are in good agreement with experimental results. Further, non linear finite element analyses was carried out on RC beams strengthened with basalt reinforced concrete. Geometric modelling, material modelling and interaction between different materials were discussed in detail. Displacement controlled analyses were performed and the response behaviour was validated by comparing with the respective experimental results. Parametric studies were conducted on RC beams strengthened with basalt reinforced concrete and the effect of volume fraction towards enhancing the flexural behaviour of RC beams was studied in detail.

Investigation on the Rheological Behavior of Fly Ash Cement Composites at Paste and Concrete Level

Abstract: Towards developing sustainable concrete, nowadays, high volume replacement of cement with fly ash (FA) is more common. Though the replacement of fly ash at 20–30% is widely accepted due to its advantages at both fresh and hardened states, applicability and acceptability of high volume fly ash (HVFA) is not so popular due to some adverse effects on concrete properties. Nowadays to suit various applications, flowing concretes such as self compacting concrete is often used. In such cases, implications of usage of HVFA on fresh properties are required to be investigated. Further, when FA replacement is beyond 40% in cement, it results in the reduction of strength and in order to overcome this drawback, additions such as nano calcium carbonate (CC), lime sludge (LS), carbon nano tubes (CNT) etc. are often incorporated to HVFA concrete. Hence, in this study, firstly, the influence of replacement level of 20–80% FA on rheological property is studied for both cement and concrete. Secondly, the influence of additions such as LS, CC and CNT on rheological parameters are discussed. It is found that the increased FA content improved the flowability in paste as well as in concrete. In paste, the physical properties such as size and shape of fly ash is the reason for increased flowability whereas in concrete, the paste volume contributes dominantly for the flowability rather than the effect due to individual FA particle. Reduced density of FA increases the paste volume in FA concrete thus reducing the interparticle friction by completely coating the coarse aggregate.

Markov chain modeling of evolution of strains in reinforced concrete flexural beams

Abstract: From the analysis of experimentally observed variations in surface strains with loading in reinforced concrete beams, it is noted that there is a need to consider the evolution of strains (with loading) as a stochastic process. Use of Markov Chains for modeling stochastic evolution of strains with loading in reinforced concrete flexural beams is studied in this paper. A simple, yet practically useful, bi-level homogeneous Gaussian Markov Chain (BLHGMC) model is proposed for determining the state of strain in reinforced concrete beams. The BLHGMC model will be useful for predicting behavior/response of reinforced concrete beams leading to more rational design.