Finite element modelling of RC slabs retrofitted with CFRP strips under blast loading

Abstract

This paper presents nonlinear finite element (FE) simulations to predict the structural behavior of simply supported reinforced concrete (RC) slabs retrofitted with carbon fiber reinforced polymer (CFRP) as externally bonded reinforcement (EBR) and subjected to the blast loads in order to evaluate the effectiveness of using the CFRP strips as EBR for blast protection. The objective of this paper is to develop detailed numerical models in order to predict the blast response of non-retrofitted and retrofitted RC slabs during the inbound and rebound phases. A plastic material model including the strain rate effects of the material and able to predict the cracks is used to model the concrete. An elasto-plastic material model and an elastic material model are used to model the steel reinforcement and the CFRP strips, respectively. The bond interface between concrete and CFRP strip is simulated using a special contact algorithm including the strain rate effect at the interface between concrete and CFRP strip with failure criteria. The numerical results are validated by experimental tests. The maximum deflections, crack distribution and strain evolution in the steel reinforcement and in the CFRP strips found by the numerical analysis are in good agreement with the experiments. The concrete material model gives a good prediction of the blast response of the RC slab with and without EBR. Increasing the amount of the CFRP strip reduces the maximum deflection at the mid span of the slabs and the strain distribution in the steel reinforcement and in the CFRP strip. Parametric studies with respect to CFRP width and CFRP thickness are performed in order to evaluate the effects on the blast response of the RC slabs.

Blast Loading of Small-Scale Circular RC Columns Using an Explosive-Driven Shock Tube

“…is used to model the concrete parts. This model, which is the third release of the Karagozian and Case (K&C) model, has been widely used to represent concrete behavior in RC structural elements subjected to blast loading [10,56]. The model uses a plasticity-based methodology featuring three shear failure surfaces and incorporates the capacity to accommodate strain rate effects.…”

“…The steel supports are defined using material type 024 (PIECEWISE_LINEAR_ PLAS-TICITY) as proposed in [56]. Detailed input parameters of the steel support are provided in Table 7.…”

Strip thickness prediction method based on improved border collie optimizing LSTM

“…The strip thickness prediction model is to express the variables involved in the strip thickness rolling process and the relationship between them through mathematics, and to control the process on this basis. With the comprehensive application of machine learning in industrial production, more and more strip thickness prediction models with neural network as the core have become popular ( Maazoun et al, 2022 ; Ganesh & Ramachandra Murthy, 2021 ). Ortmann (1994) took the lead in using neural networks to develop prediction models for parameters such as roll width, surface temperature and rolling force, which greatly improved the prediction accuracy.…”