© 2021 IIETA. This article is published by IIETA and is licensed under the CC BY 4.0 license (http://creativecommons.org/licenses/by/4.0/).
OPEN ACCESS
This work deals with the response of eight reinforced concrete (RC) slabs, made at full-scale, some of them with the addition of externally bonded fibre reinforced polymer (FRP). The reinforcements were placed in all cases on the face opposite to the explosive detonation. Three scaled distances have been used from 0.83 m/kg1/3, in one test with no extra reinforcement; four tests were made with a scaled distance of 0.42 m/kg1/3: one without extra reinforcement, two with carbon fibre reinforcement (CFRP) and one with the E-glass fibre reinforcement (GFRP); finally, 0.21 m/kg1/3, in three trials, one without extra reinforcement, one with carbon fibre reinforcement and one with the E-GFRP. The first slab, used for calibration of the numerical models, was instrumented with pressure and acceleration sensors. For the validation of the other seven slabs, the damage surfaces on both sides of the slabs are used. In terms of numerical simulation performed with LS-DYNA, several models covering different solutions such as smooth particle hydrodynamics (SPH) or load blast enhanced have been performed for the description of the explosive, as well as the use of CSCM material models for concrete to analyse the best available solutions. The steel was modelled with the piecewise linear plasticity material, while the material laminated composite fabric was used for the FRP. Reinforcement with CFRP resulted in a generally reduced damage area on both surfaces. All models show a good correlation, including non- spherical charges made with SPH models, with the test results when comparing them with respect to acceleration and surface damage. SPH models work well for the high and medium scaled distance, but not so good for the shorter scaled distance.
explosive, FEM simulation, full-scale tests, slabs
[1] Zhang, C. & Mousavi, A.A., Blast loads induced responses of RC structural members: State-of-the-art review. Composites Part B: Engineering, 195, p. 108066, 2020. https:// doi.org/10.1016/j.compositesb.2020.108066
[2] Thai, D.K., Nguyen, D.L., Pham, T.H. & Doan, Q.H., Prediction of residual strength of FRC columns under blast loading using the FEM method and regression approach. Construction and Building Materials, 276, p. 122253, 2021. https://doi.org/10.1016/j. conbuildmat.2021.122253
[3] Castedo, R., Segarra, P., Alañón, A., Lopez, L.M., Santos, A.P., &Sanchidrian, J.A., Air blast resistance of full-scale slabs with different compositions: Numerical modeling and field validation. International Journal of Impact Engineering, 86, pp. 145–156, 2015. https://doi.org/10.1016/j.ijimpeng.2015.08.004
[4] Badshah, E., Naseer, A., Ashraf, M., Shah, F. & Akhtar, K., Review of blast loading models, masonry response, and mitigation. Shock and Vibration, 2017.
[5] Lantz, L., Maynez, J., Cook, W. & Wilson, C.M.D., Blast protection of unreinforced masonry walls: A state-of-the-art review. Advances in Civil Engineering, 2016.
[6] Bermejo, M., Santos, A.P., & Goicolea, J.M., Development of practical finite element models for collapse of reinforced concrete structures and experimental validation. Shock and Vibration, 4636381, 2017.
[7] Terranova, B., Whittaker, A. &Schwer, L., Design of concrete walls and slabs for wind- borne missile loadings. Engineering Structures, 194, pp. 357–69, 2019. https://doi. org/10.1016/j.engstruct.2019.05.001
[8] Kumar, V., Kartik, K.V. & Iqbal, M.A., Experimental and numerical investigation of rein- forced concrete slabs under blast loading. Engineering Structures, 206, p. 110125, 2020. https://doi.org/10.1016/j.engstruct.2019.110125
[9] Livermore Software Technology Corporation (LSTC). LS-DYNA Keyword User’s Manual - R11 2018:3186.
[10] ANSYS. AUTODYN User Manual Version 15.0 2013.
[11] Kingery, C. &Bulmash, G., Airblast parameters from TNT spherical air burst and hemispherical surface burst. US Army Armament and Development Center, Ballistic Research Laboratory, 1984.
[12] Chiquito, M., Castedo, R., López, L.M., Santos, A.P., Mancilla, J.M., &Yenes, J.I., Blast wave characteristics and TNT equivalent of improvised explosive device at small scaled distances. Defence Science Journal, 69(4), pp. 328–335, 2019. https://doi.org/ 10.14429/dsj.69.13637
[13] UFC 3-340-02. Structures to resist the effects of accidental explosions. US Department of the Army, Navy and Air Force Technical Manual, 2008.
[14] Gomathi, K.A., Rajagopal, A., Reddy, K.S.S. & Ramakrishna, B., Plasticity based mate- rial model for concrete subjected to dynamic loadings. International Journal of Impact Engineering, 142, p. 103581, 2020. https://doi.org/10.1016/j.ijimpeng.2020.103581
[15] Tai, Y.S., Chu, T.L., Hu, H.T. & Wu, J.Y., Dynamic response of a reinforced concrete slab subjected to air blast load. Theoretical and Applied Fracture Mechanics, 56(3), pp. 140–147, 2011. https://doi.org/10.1016/j.tafmec.2011.11.002
[16] UNE-EN 1992-1-1:2013: Eurocode 2: Design of concrete structures - Part 1-1: General rules and rules for buildings, 2013.
[17] Castedo, R., Santos, A.P., Alañón, A., Reifarth, C., Chiquito, M., López, L.M., Martínez- Almajano, S. & Pérez-Caldentey, A., Numerical study and experimental tests on full- scale RC slabs under close-in explosions. Engineering Structures, 231, p. 111774, 2021. https://doi.org/10.1016/j.engstruct.2020.111774
[18] Alañón, A., Cerro-Prada, E., Vázquez-Gallo, M.J., & Santos, A.P., Mesh size effect on finite-element modeling of blast-loaded reinforced concrete slab. Engineering with Computers, 34(4), pp. 649–658, 2018. https://doi.org/10.1007/s00366-017-0564-4
[19] Hashin, Z., Failure criteria for unidirectional fiber composites. Journal of Applied Mechanics, 180, pp. 329–334, 1980. https://doi.org/10.1115/1.3153664
[20] García, C.R., Modelización de losas de hormigón armado frente a explosiones. Univer- sidad Politécnica de Madrid, 2020.
[21] Cherniaev, A., Montesano, J., & Butcher, C., Modeling the axial crush response of CFRP tubes using MAT054, MAT058 and MAT262 in LS-DYNA®. In Proceedings of the 15th International LS-DYNA® Users Conference, Detroit, MI, USA, pp. 10–12, 2018.
[22] Li, J., Wu, C., Hao, H., & Su, Y., Experimental and numerical study on steel wire mesh rein- forced concrete slab under contact explosion. Materials & Design, 116, pp. 77–91, 2017. https://doi.org/10.1016/j.matdes.2016.11.098