Probabilistic capacity models and fragility estimate for NRC and UHSC panels subjected to contact blast

A Performance-based Design (PBD) framework for protective structural walls/slabs susceptible to contact blast has been developed. Performance-based capacity models are predicted for three performance levels namely, operation with minimum damage (P1), medium damage (P2) and collapse prevention (P3) allied to four damage states. The current study examines multi-level PBD instead of single-level conventional collapse-based design. All these probabilistic models are developed by combining mechanical models with dimensionless explanatory functions. Bayesian inference based on numerical data is used to evaluate the unknown model parameters. The constructed models take into account all inherent aleatoric and epistemic uncertainties of material and geometry. For Normal Reinforced Concrete (NRC) and Ultra-high Strength Concrete (UHSC) panels subjected to contact blast, finite element (FE) modelling (LS-DYNA) is used to obtain the necessary data. The validated models have a high level of agreement with chosen experimentation. In addition, local damage formulations, such as crater diameter, crater depth, spall diameter, spall depth, and perforation diameter, are also developed. The developed capacity models are used to estimate fragility, and the obtained plots demonstrate the consistency of the evaluated equations. When subjected to a contact blast, these probabilistic models can be used to construct protective structures based on the expected demand.

Automated summary

A performance-based design framework has been developed for protective structural walls/slabs susceptible to contact blast. The framework includes performance-based capacity models for different performance levels and damage states, and probabilistic models that consider both aleatoric and epistemic uncertainties. Bayesian inference is used to evaluate the unknown model parameters. Finite element modeling is used to obtain necessary data for reinforced concrete and ultra-high strength concrete panels subjected to contact blast. The validated models show agreement with experimentation. The developed capacity models are used to estimate fragility and construct protective structures based on the expected demand.