Evaluation of critical damage location of contact blast on conventionally reinforced one-way square concrete slab applying CEL-FEM blast modeling technique

Abstract

Nowadays, accidental explosions in residential and factory buildings are common owing to poor maintenance and mishandling of fuel gas and chemical explosive appliances leading to grievous injuries and infrastructure damages. Contact blast on slabs using explosives is noticed as a simpler act of subversion as compared to other components of the building and is more damaging than a close-in blast. In general, damage caused by contact blast is localized in the form of concrete cratering, scabbing, and rupture of the reinforcement. A recently published state-of-the-art review on the performance of reinforced concrete (RC) slabs under contact and close-in explosion loading scenario by the authors (Anas et al., 2021b) reveals the common perception for the location of contact blast to cause maximum damage is the centroid of the slab. It develops a curiosity with sufficient interest to investigate the effect of the location of contact explosive charge on the damage response of the slab. Several numerical techniques such as empirical, ConWEP (semi-empirical), Smooth Particle Hydrodynamics (mesh-free method), and Coupled-Eulerian-Lagrangian (CEL) are in use for simulation of blast loading on structures. Current literature reveals that the CEL is the most advanced and realistic blast modeling technique. This study applies Coupled-Eulerian–Lagrangian (CEL) formulation with finite element method (FEM) using the dynamic computer code ABAQUS/Explicit-v.6.15 to investigate the performance of singly reinforced one-way spanning concrete slab subjected to concentric contact blast loading. The numerical model is validated with the experiment results in the open literature. The validated model is then employed to investigate whether or not the maximum damage is really caused by the central location of the contact blast. For this purpose, one-quarter of the slab with nine symmetrical points (or locations) of contact blast of explosive charge, which reflect the coverage of the entire slab, in contact with the top face of the slab is considered in the study. Two constitutive material models, Concrete Damage Plasticity and Johnson–Cook, with strain rate effects are used to simulate the non-linear behavior of the concrete and steel, respectively. The results reveal that the most critical location of maximum damage to the slab is along the line of symmetry parallel to the supports at an eccentricity of B/4 from the centroid of the slab, where “B” is the width of the one-way slab.

Ultra high performance concrete and C-FRP tension Re-bars: A unique combinations of materials for slabs subjected to low-velocity drop impact loading

“…In Refs. (Sadraie et al, 2019;, Shariq et al, 2022a;Tahzeeb et al, 2022a;Tahzeeb et al, 2022b;Tahzeeb et al, 2022c;Ul Ain et al, 2021;Ul Ain et al, 2022;Anas et al, 2022i;Anas et al, 2022j;Ahmadi et al, 2022;Shariq et al, 2022b;Shariq et al, 2022c;Shariq et al, 2022d;Anas et al, 2022k;Anas and Alam, 2022d;Anas et al, 2022m;Anas et al, 2022n;Shariq et al, 2022e;Anas et al, 2022o;Anas et al, 2022p;Shariq et al, 2022f;Anas and Alam, 2022e;Shariq et al, 2022g;Anas et al, 2022q;Shariq et al, 2022h;Anas et al, 2022r) employ the Concrete Damage Plasticity (CDP) model, which takes the strain-rate effect into account. A damage plasticity model can be used to describe the mechanical behavior of concrete.…”

Effect of thermal cycles on the engineering properties and durability of sustainable fibrous high-strength concrete

“…The matrix and reinforcement were revealed to have good chemical resistance and interfacial bonding. Mishra et al (2003) used chemically altered sisal fibres as reinforcement in the polyester matrix, in addition to glass fibres, to enhance the mechanical characteristics of the hybrid composites (Anas et al, 2022d;Anas et al, 2022g). The test results reveal that hybrid composites absorb less water than unhybridized composites (Althoey et al, 2022b;Hakeem et al, 2022c).…”

Performance of (1) concrete-filled double-skin steel tube with and without core concrete, and (2) concrete-filled steel tubular axially loaded composite columns under close-in blast

“…The study of the blast resistance of conventionally designed structures has become significantly important in recent years in light of the increase in global terrorism (Anas and Alam, 2021a; Anas et al, 2022a, 2022b, 2022c; Anas and Alam, 2022; Anas et al, 2022d, 2022e, 2022f). Conventional structural design principles require loads to be transferred safely to the foundations through defined load paths and in such a way that failure of one component does not lead to failure of a disproportionate part or of the entire structure (Anas et al, 2021d; Anas et al, 2022f). Thus, structural components such as columns are detailed with stringent performance requirements.…”

“…Understanding the performance of such composite columns subjected to short-duration/high-magnitude blast loading is vital for improvements of its design under the prevailing environment of Hi-tech wars, subversions, and accidental detonations (Anas et al, 2021b). Recent devastating Beirut explosion and very recent gas pipe explosion in China’s Hubei province are examples of accidental blasts (Anas et al, 2022b, 2022c; Anal and Alam, 2022; 2022d; 2022e; 2022f). Moreover, the world has witnessed small-scale wars out of the conflicts between Russia and Ukraine, Palestine and Israel, in addition to ongoing subversive activism in many other countries involving blasts to damage buildings and other infrastructure (Anas et al, 2021b).…”

“…The blast waves generated from an explosion exert a transient dynamic load on structures. The short duration impulsive load and resulting inertial forces generated due to the acceleration of the structure are resisted by internally generated strain energy (Anas, Alam, et al, 2022; Anas et al, 2021; Anas, Shariq, et al, 2022; Anas and Alam, 2021; ASCE/SEI 59-11, 2011; Baker et al, 1983; Shi et al, 2007). The response of structural elements subjected to blast loading can be investigated through field testing or numerical modelling (Anas et al, 2021d).…”