Urban Habitat Constructions under Catastrophic EventsFINAL CONFERENCE. Naples, 16th- 18th September 2010Chair of the Action: Federico Mazzolani, IT, fmm@unina.itCOST Science Officer: Thierry Goger, tgoger@cost.esf.org

COST Action C26

TITLE OF PAPER: Behaviour of deformable blast walls for protective structural design

Authors: S.A. KILIC* P.D. SMITH**

Affiliation: *Bogazici University, Civil Eng. Dept., Istanbul, Turkey **Cranfield University, Defence Academy, Shrivenham, U.K.

ABSTRACT: The response of deformable reinforced concrete blast walls is investigated using the commercial

finite element code LS-Dyna. The design of the wall is based on 20 kg of TNT-equivalent mass of explosive

material. The amount of explosive material is further increased and the damage pattern of the wall is

demonstrated in the finite element analysis results. Significant wall failure occurs when the amount of explosive

material is increased well beyond the 20 kg design level.

Reinforced concrete blast wall parametric study.

Numerical analyses presented in the study.

Analyis R WTNT he H Z [scaled dist.] t qmax

Code (m) (kg) (m) (m) (m/kg^0.33) (m) (degree)____

F20 2.0 20 2.0 3.0 .7368 0.35 0.56

F30 2.0 30 2.0 3.0 .6347 0.35 0.86

F50 2.0 50 2.0 3.0 .5429 0.35 1.62

F100 2.0 100 2.0 3.0 .4309 0.35 X

F200 2.0 200 2.0 3.0 .3420 0.35 X

___________F815 2.0 815 2.0 3.0 .2141 0.35 X________

State of the finite element mesh for the F20 analysis

showing the reinforcement details and the damage

pattern after the blast wave-front hits the blast wall .

F20 analysis pressure contours on the exposed surface of the blast wall

at the reference time steps of (a) 0.05, (b) 0.10. (c) 0.15 and (d) 0.20

milliseconds.

(a) (b)

(c) (d)

Damage pattern on the walls for the (a) F20, (b) F30, (c) F50, (d) F100, (e) F200, and (f) F815 analyses.

(a) (b)(c)

(d) (e) (f)

CONCLUSIONS: A realistic impulsive design of reinforced concrete blast walls has been carried out using the available

codes of practice for an explosive charge of 20 kg TNT. The amount of explosive material is increased in stages up to 815

kg TNT. The LS-Dyna finite element code results demonstrate the capability of the numerical simulations to show the extent

of the wall damage. Significant failure of the blast wall occurs for amounts over 30 kg TNT as shown in the F50, F100,

F200, and F815 analyses. The F100, F200, and F815 analyses illustrate the complete failure of a segment of the wall right

in front of the explosive material. Failure on the top portion of the wall occurs when a circular region is punched out of the

wall plane due to the high intensity of the blast wave and the high level of the impulse.