Implicit and Explicit Analysis of the Response of Blast Loaded Reinforced Concrete Slabs

Kamel S. Kandil, Mouhamad T. Nemir, Ehab A. Ellobody, Ramy I. Shahin

Department of Civil Engineering, Faculty of Engineering, Menoufiya University, Shibin El Kom, Egypt.
Department of Structural Engineering, Faculty of Engineering, Tanta University, Tanta, Egypt.

DOI: 10.4236/wjet.2014.23023                

Abstract

Implicit and explicit analyses were examined with experimental work done by Razaqpur et al. In the experiment work, two 1000 × 1000 × 70 mm reinforced concrete slabs were constructed. The slabs were subjected to blast loads generated by the detonation of either 22.4 kg or 33.4 kg of ANFO located at a 3.0 m standoff. Blast wave characteristics, including incident and reflected pressures and reflected impulses were measured. The slabs were modeled by implicit and explicit analysis to study their behavior under blast load to compare their predicted and observed behavior. The post-blast damage and mode of failure of each slab were observed. It was concluded that explicit analysis provides better modeling than implicit analysis.

Keywords

Implicit Analysis, Explicit Analysis, Strain Rate, Blast Load, Ansys, Ls-Dyna, Scaled Distance

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Ghani Razaqpur, A., Tolba, A. and Contestabile, E. (2007) Blast Loading Response of Reinforced Concrete Panels Reinforced with Externally Bonded GFRP Laminates. Elsevier Journal of the Composites: Part B, 38, 535-546. http://dx.doi.org/10.1016/j.compositesb.2006.06.016
[2]	TM-5-1300 (1990) Design of Structures to Resist the Effects of Accidental Explosions. Technical Manual, US Department of the Army, Washington DC.
[3]	Wu, C.Q. and Hao, H. (2005) Modeling of simultaneous Ground Shock and Airblast Pressure on Nearby Structures from Surface Explosions. Elsevier International Journal of Impact Engineering, 31, 699-717. http://dx.doi.org/10.1016/j.ijimpeng.2004.03.002
[4]	Wua, C.Q. and Hao, H. (2007) Numerical Simulation of Structural Response and Damage to Simultaneous Ground Shock and Airblast Loads. Elsevier International Journal of Impact Engineering, 34, 556-572. http://dx.doi.org/10.1016/j.ijimpeng.2005.11.003
[5]	Ellobody, E. and Bailey, C.G. (2008) Behaviour of Unbonded Post-Tensioned One-Way Concrete Slabs. Reprinted from Advances in Structural Engineering, 11, 117-120.
[6]	ANSYS, ANSYS User’s Manual, Version 11.0, ANSYS, Inc.
[7]	Kachlakev, D. and Miller, T. (2001) Finite Element Modeling of Reinforced Concrete Structures Strengthened With FRP Laminates. SPR 316, Oregon Department of Transportation Research Group & Federal Highway Administration, Washington DC.
[8]	Livermore Software Technology Corporation (2003) Ls-Dyna Theoretical Manual. Livermore Software Technology Corporation, California.
[9]	Faust, B. (2002) Evaluation of the Residual Load-Bearing Capacity of Civil Structures Using Fuzzy-Logic & Decision Analysis. Universitat Der Bundeswehr, Neubiberg.
[10]	Lu, Y. and Xu, K. (2004) Modeling of Dynamic Behaviour of Concrete Materials under Blast Loading. International Journal of Solids and Structures, 41, 131-143. http://dx.doi.org/10.1016/j.ijsolstr.2003.09.019
[11]	Javier Malvar, L. and Crawford, J.E. (1998) Dynamic Increase Factors for Concrete. Twenty-Eighth DDESB Seminar, Orlando, August 1998.
[12]	Moon, N. (2009) Prediction of Blast Loading and Its Impact on Buildings. Master of Technology in Civil Engineering Thesis, Department of Civil Engineering, National Institute of Technology, Rourkela.
[13]	Ngo, T., Mendis, P., Gupta, A. and Ramsay, J. (2007) Blast Loading and Blast Effects on Structures—An Overview. Electronic Journal of Structural Engineering, EJSE Special Issue: Loading on Structures, 76-91.