NUMERICAL INVESTIGATION OF LOCAL AND GLOBAL RESPONSE OF REINFORCED CONCRTE SLABS BUNDER WIDE RANGE OF BLAST DETRONATIONS

This Research project is aimed at investigating the local and global damage of reinforced concrete slabs under wide-range of blast loads, intended to be used for local failure prediction of concrete structural elements and post-blast response of structural systems such as bridge structures. Intellectual Merits of the Proposed Activity: Spalling and cratering are common modes of failure in concrete structures subjected to close-in detonations. There is limited data and models available on the prediction of the spalling/cratering of reinforced concrete members under blast loads. Currently engineers rely on empirical curves to assess whether breach occurred or not. Friendly user engineering tools that can be used to estimate the cratering/spalling damage level and crater size of concrete members under close-in detonations are needed. The damage level is critical to be able to predict the dynamic response of a structural system, such as a bridge, after a close-in explosion. The proposed project will develop an Artificial Neural Network (ANN) model capable of predicting the damage (spalling/cratering) size. The ANN model will be based on training and testing data sets developed using the finite element approach LS-DYNA. The numerical model will be reliable for detecting the highly dynamic response of the concrete member under severe blast loads. The numerical simulation and the engineering analysis and design tool will be significant contributions to this field of blast effects and modeling. The proposed research will advance the knowledge in the area of modeling and testing under high strain rates, and provide new opportunities for engineering education and improved design in the Kingdom of Saudi Arabia. Broader Impacts of the Proposed Activity: The engineering blast analysis and design community is in critical need of blast-resistant design guides for various structural applications. In particular, the response of concrete walls/slabs to near-field detonations is not well-defined. Currently, engineers rely on experts for field testing for predicting the damage and structural response under close-in blast threats. Predicting the level of damage under such loading is critical for performing post detonation dynamic analysis of the structure to predict the global response and failure mechanism of the system. This is particularly important for bridge superstructures under blast threat directed to the deck or tower system since the standoff distance cannot be controlled. The results of this research on the material response can be incorporated into research efforts for the dynamic response of structural systems, such as bridges, under blast. In addition, the findings of this research project can be extended for developing innovative blast mitigation technologies, such as functionally graded materials and composites, for protection against close-in detonations. Therefore, this research will have a great impact on the Kingdom of Saudi Arabia national efforts for advancing the intellectual state-of-the-art and for developing new models and technologies for protection against the threat of explosions.