COMBINED BLAST AND FRAGMENT LOADING EFFECTS ON REINFORCED CONCRETE STRUCTURES · · 2016-03-111...
Transcript of COMBINED BLAST AND FRAGMENT LOADING EFFECTS ON REINFORCED CONCRETE STRUCTURES · · 2016-03-111...
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COMBINED BLAST AND FRAGMENT LOADING EFFECTS ON REINFORCED
CONCRETE STRUCTURES
Yau Jia Ming Spencer
1, Kang Kok Wei
2
1Anglo Chinese Junior College, 25 Dover Close East Singapore 139745
2Defence Science and Technology Agency, 1 Depot Road, Singapore 109679
ABSTRACT
Concrete has been used since the Roman Empire and has been made stronger in modern
times with the addition of steel reinforcing bars (rebars), which form reinforced concrete
(RC). The cost effectiveness, reasonable strength and high malleability has contributed to its
popularity in the construction industry. This research study aims to understand the response
of RC slabs against combined blast and fragment loadings in the design of protective
structures. Since small countries such as Singapore suffer from land space constraint,
practical experiments are limited thus the need for computation software such as LS-DYNA,
which is used in this study. Through LS-DYNA, parameters such as arrangement of rebars
and boundary conditions, have been varied to study the response of RC against blast as well
as combined blast and fragment loadings. Findings include the decreasing relationship of the
damage extent of the RC slab to increments of rebars as well as the stark difference in the
response of the RC against combined blast and fragment loading compared to its response
against blast loading solely.
INTRODUCTION
Resilience of reinforced concrete (RC) structures to dynamic loadings has been well
researched in the protection of human or equipment within buildings. The loading effects
from conventional weapons include both blast and fragments. The latter is generated from the
breakup of metal casing around the explosives within. While blast and fragment loadings are
well documented individually, there are limited data on the combined blast and fragment
loading effects. The objective of this research is to analyse the physical response of an RC
slab to combined blast and fragments loadings.
Since small countries such as Singapore suffer from land constraints, practical experiments to
study the combined blast and fragment effects are limited thus the need for computation
software such as LS-DYNA. Apart from saving resources, numerical analysis using these
computational software develop trends or patterns without the need for numerous live testing.
However, such software and simulations run on equations that are built on data only found
through experiments. Hence, some live testing is still required.
This paper is divided into 2 sections: Blast Loading on RC Slabs and Combined Blast and
Fragments Loading on RC Slabs. Each section will discuss about their respective loading,
present the methods and discuss the results.
RESEARCH APPROACH
In the analysis of the RC slab subjected to various dynamic loadings, the software, LS-
DYNA, which originated from the Lawrence Livermore National Laboratory in 1976, is
used. This software is primarily used to numerically analyse structures which are subjected to
a variety of impact loading. For this research, we will be analysing the stress visually and z-
displacement graphically of the RC slab when it is loaded. An example of stress analysis can
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be seen in Figure 1 [1]. Usually, the red regions will indicate high stress values and vice versa
for blue regions.
Figure 1: An example of visual stress analysis [1]
Packaged together with the LS-DYNA Solver is a software called LS-PrePost. This is a both
a PreProcessor as well as a PostProcessor. The former allows users to setup models prior to
the analysis while the latter enables users to analyse and visualise the output from LS-DYNA.
For this research study, the PreProcessor is used to create a slab model, which measures
3x1x0.2m and the following parameters are varied:
Boundary conditions,
Element Size
Arrangement and number of loading segments
Arrangement and number of rebars
Figure 2 Measurements of the RC slab model
Details of the parameters above will be described in subsequent sections. The rest of the
parameters such as the ones below can be created using LS-PrePost but, in this study, a
separate file is written using the computer program WordPad to specify these values into the
model:
charge mass,
stand-off distance, and
the type of loading (blast and combined blast and fragments for this research)
An example of the file is included in the Annex A.
After analysing the model using LS-DYNA, the PostProcessor allows the user to analysis the
damage and response of the RC slab loading visually and graphically. For the graphs, only
the first peak deflection is considered as the subsequent oscillations of the slab is deemed
unphysical. Given more time, this problem can be numerically resolved.
0.2m
1m
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BLAST LOADING
This section describes the analysis of a RC slab subjected to blast loadings, which assumes
the use of bare Trinitrotoluene (TNT). The shape of the charge is assumed to be spherical and
it is detonated in the air. This is known as airblast. Variations of the quantity and arrangement
of rebars, boundary conditions, element size and scaled distances were studied in this
research. Fortunately, LS-DYNA can calculate the blast load data. Hence there is little need
for manual calculations. Grade 30 concrete and Grade 460 steel for the rebars in the model.
Quantity & Arrangement of rebars
In RC slabs, rebars are important as they contribute greatly to the tensile capacity of RC.
Concrete is highly resistant to compressive stresses but responds poorly to tensile stress.
Therefore, the quantity and arrangement of rebars can alter the capacity of RC slabs to blast
loading. For this study, 20x20x20mm solid elements are used to model concrete while the
rebars are modelled using 20mm long beam elements. An explosive charge weighing 10kg,
which is placed 2m above the top surface of the slab, is detonated in this case. Three models
are created in this study. The models in Figures 3(a) and 3(b) have two layers of rebars but
the number of rebars per layer is varied: 5 rebars per layer for Figure 3(a) and 10 rebars per
layer for Figure 3(b). The model in Figure 3(c) is similar to the one in Figure 3(a) but without
a layer of rebars near the top surface.
(a) (b) (c)
Figure 3 Models used to study the effects of varying the rebar quantity and
arrangement
By comparing images in Figures 4(a) and 4(b) and the curves in Figure 5 (Figure 4(a) having
10 rebars and Figure 4(b) having 20 rebars), there is a decrease in the overall midspan
vertical- or z-displacement of the slab and damage when the quantity of rebars increase. The
same can be said when the number of rebar layers increase in the case of Figures 4(a) and
4(c) (Figure 4(c) having 5 rebars). When the slabs are bent as shown in Figure 6, the top
surface of the slab is subjected to compression while the bottom of the slab is subjected to
tension. Since rebars have a higher tensile strength than concrete, the overall tensile strength
of the slab increases with increments in rebar content, which reduces the overall z-
displacement of the slab as well as the damage.
(a) (b) (c)
Figure 4 Damage of the soffit of the slabs with various rebar arrangements after loading
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Figure 5 Midspan displacement histories of the slabs with various rebar arrangements
Boundary Conditions
Figures 6 Bending response of the RC slabs under blast loading
There are 2 main types of supports for RC structures: pinned and fixed. Pinned support
provides translational restraints but not rotational restraint at the ends whereas fixed support
provides both translational and rotational restraints. Two models were created to study the
effects of these boundary conditions. Figures 6(a) & 6(b) represent fixed and pinned supports
respectively. The entire surfaces of the model in Figure 6(a), which are darkened, are
restrained whereas, for the model in Figure 6(b), only an edge on the soffit of the slab has
been restrained. They are also illustrations of both boundary conditions and their appearances
in the models [2]. The other parameters remain unchanged and the models are similar to the
one in Figure 3(a).
(a) (b)
Figure 6 Models used to study the effects of varying the boundary conditions
The RC slab with fixed supports in Figure 7(a) suffered less damage than the slab with
pinned supports in Figure 7(b). The z-displacement is significantly greater for the slab with
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pinned supports than the slab with fixed supports as seen in Figure 8. Pinned supports are
commonly seen in pre-cast concrete buildings such as the many HDB flats in Singapore. An
example of a structure with fixed supports is a bomb shelter as it is a single piece of structure
with no weak linkages. Since fixed supports offer more resistance to rotational movement
(moment) than Pinned supports, the slab with fixed supports will be more resilient to loading
forces and pressure exerted, resulting in less damage; as observed in Figures 7(a) and 7(b).
(a) (b)
Figure 7 Damage of the soffit damage of the slabs with (a) fixed and (b) pinned supports
after loading
Figure 8 Midspan displacement histories of the slabs with fixed and pinned supports
Element Size
In LS-PrePost, 2 meshes of the RC slab described in Figure 3(a) are formed but the number
of elements are varied as it was believed that this parameter has an effect on the RC slab
response to impact loading. The slab in Figure 9(a) consists of 1,000 solid elements of
300x100x20mm while the slab in Figure 9(b) comprises of 75,000 solid elements of
20x20x20 mm.
(a) (b)
Figures 9 Models used to study the effects of varying the element size
The slab made of small solid elements in Figure 10(a) has suffered significantly less damage
from the impact loading than the slab made of large elements in Figure 10(b). At stand-off
distances of 1m & 2m and charge mass of 10kg, there is almost no difference in the z-
displacement of the slab as seen in Figure 11. However, for the stand-off distance at 2.15m
and charge mass of 100kg, the slab in Figure 10(a) has a smaller z-displacement than the slab
in Figure 10(b) as seen in Figure 11; showing an increasing relationship of the z-displacement
and the stress as the quantity of elements increases. It could be due to the average impulse,
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from the blast loading, per element being higher for the slab in Figure 10(a) than the slab in
Figure 10(b); tallying with the results.
(a) (b)
Figure 10 Damage of the soffit of the slabs with (a) small and (b) large elements after
loading
Figure 11 Midspan displacement histories of the slabs with various element sizes at
various stand-off distances and charge mass
Scaled Distance
Scaled distance is defined as the ratio R/C1/3
where R is the stand-off distance of the
explosive charge from the target and C the explosive charge mass. Most blast parameters can
be derived from scaled distance as shown in Figure 12. Two scaled distances are studied in
this section: 0.46m/kg1/3
and 0.92m/kg1/3
. The former is based on a 10kg explosive mass at
stand-off distance of 1m while the latter is based on the same explosive quantity at a stand-off
distance of 2m. For the former, another scenario of a 100kg explosive mass with a stand-off
distance of 2.15m is studied.
Figure 12 Derivation of various blast parameters based on scaled distance [3]
Figures 13(a), 13(b) and 13(c) shows the damage of the three scenario studied. As expected, a
higher scaled distance will lead to less damage by comparing Figures 13(a) and 13(b), in
which the charge weights are the same but the stand-off distances are 1m and 2m
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respectively. It is also noted that although the scaled distances are the same for the slabs in
Figure 13(a) and 13(c), the use of a higher charge mass on the slab in Figure 13(c) resulted in
a larger amount of explosive materials reacted, producing more kinetic energy and thus a
very powerful shockwave. This will lead to more damage. The z-displacement histories of the
three scenarios are plotted in Figure 14 and the results relate well with the damage
comparisons in Figure 13. Thus, in addition to scaled distance, the individual components of
this expression i.e. the explosive charge mass and stand-off distances are also important.
(a) (b) (c)
Figure 13 Damage of the soffit of the slabs with various scaled distances of (a)
0.46m/kg1/3
(10kg@1m), (b) 0.92m/kg1/3
(10kg@2m) and (c) 0.46m/kg1/3
Figure 14 Midspan displacement histories of the slabs with various scaled distances of
(a) 0.46m/kg1/3
(10kg@1m), (b) 0.92m/kg1/3
(10kg@2m) and (c) 0.46m/kg1/3
COMBINED BLAST AND FRAGMENTS LOADING
The preceding section focuses on loading from a bare spherical charge but, under the loading
of an exploding weapon, there are fragments generated in addition to the blast. Hence it is
important to consider the combined blast and fragment loading of a cased charge when
building a RC structure designed against weapons. This section studies and discusses the
combined effects of blast and fragments by implementing an engineering methodology to
predict the loading. Though there are built in values for blast loading, the fragment loading
data has to be calculated separately and inserted into the model manually. The RC slab,
which this study focuses, is similar to the one shown in Figure 2 and the cased charge
considered is shown in Figure 15. This type of explosive is commonly known as a pipe bomb.
Figure 15 Dimensions of the cased charge in the study
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Methodology for the Prediction of Combined Blast and Fragment Loading
It is important to pinpoint the parameters to calculate the combined blast and fragment
loading from a cased charge. From past research, these important parameters are the mass of
an explosive charge and casing and the stand-off distance of the charge from the target. The
steel pipe surrounding the explosives within has an external diameter of 0.2m and a thickness
of 0.04m. The height of the cased charge is 0.6m. Assuming that the steel and explosives
densities are 7,860kg/m3 and 1,600kg/m
3, the mass of the casing and explosives are 94.8kg
and 10.9kg respectively.
Other than the casing and explosive charge mass and the stand-off distance, it is important to
identify the spread of the fragment load. Unlike blast loading, which affects the entire
exposed surface, the area in which the fragments are projected is limited. This is observed in
one of the tests conducted by the Norwegian Defence and Estates Agency [4]. It is observed
that the angle of fragments spread from the casing of a 155mm artillery shell at a stand-off
distance of 1m is approximately 15 (see Figure 16). This angle will be used in the
subsequent calculations.
(a) (b)
Figure 16: Side view of the test (a) before and (b) after detonation
Figure 17 showing the different stand-off distances and fragment-targeted segments
To find the stand-off distances, a diagram of the slab and charge positions were drawn. With
differing horizontal displacements of the fragments from the charge (bases of the triangles in
Figure 17), a constant vertical height of 2m (all the triangles share the same vertical height)
and the 15 fragment angle found in Figure 16 (labelled in Figure 17), a variation of stand-off
distances (hypotenuse of the triangles) can be obtained. Figure 17 is an example of the slab
divided into 6 segments (1 triangle per segment) and will be important for the upcoming
section; Orientation of the bomb.
~15o
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Figure 18 Pressure-Time history of fragment loading
As described in preceding sections, parameters to define blast loading can be derived from
charts such as the one shown in Figure 12 and computation software such LS-DYNA can
calculate the loading automatically. This is not so for fragment loading, which has to be
derived. The data required for the fragment loading are the peak pressure, estimated time of
arrival of the fragments (ETA), the loading duration (to) and the estimated time of termination
of the fragment loading (ETT). The graph in Figure 18 shows the relationship between these
properties.
To find the peak pressure, we will need to calculate the area underneath the graph and blast
duration. The area underneath the graph is equivalent to the fragment impulse IM. This can be
derived based on Equation 1 in which IO is bare charge impulse and M is casing mass [5]. IO
can be derived based on the scaled distance from Figure 12.
√
To find the loading duration, we need to find the Equivalent Bare Charge mass (EBC) for the
pipe bomb. To find this mass, we have to use the modified Fisher Equation [6]. A research
study done by Hartmann & Rottenkolber [7] has shown that for cased charges with thick and
brittle casings whereby their casing to charge mass ratios
are greater than 2, the modified
Fisher equation (as shown in Equation 2 below) could make good predictions of the EBC.
( [
( ⁄ )
])
Based on the EBC and stand-off distance, the loading duration to can be obtained from Figure
12. By using
, which is the inverse formula for the area of a triangle, the peak pressure
can be obtained. To obtain the ETA, we need the stand-off distance and the impact fragment
velocity VoI which can be found using Gurney’s equation [8]. The impact fragment velocity
can be expressed as [
]
where VoI is the initial fragment velocity and
G is the Gurney explosive energy constant. For this study, TNT is used hence the Gurney’s
constant value is approximately 2.44 km/s. The ETA of the fragments is calculated using
and it varies per segment. The ETT is the summation of to and the ETA.
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Orientation of the bomb
Figures 19(a) and 19(b) below show the 2 different orientations of the pipe bomb. The
calculated fragment spread angle is used to find the segments the fragments are hitting after
detonation. As aforementioned, the linear distance from the charge core to the centre of a
segment is used as the stand-off distance, resulting in variations of fragment impulse values
per segment. In reality, these variations are significantly more diverse and unpredictable.
(a) (b)
Figure 19 showing the different orientations of the pipe bomb
The loading condition in Figure 19(b) resulted in more damage and z-displacement than the
other position. Figures 20(a) and 20(b) shows the damage of the loading on the slabs in
Figure 19(a) and 19(b) respectively and Figure 21 shows the z-displacement variation. Since
the affected area is greater in Figure 19(b) than Figure 19(a), it will be logical for more
damage and deflection increase in Figure 20(b) compared to Figure 20(a).
(a) (b)
Figure 20 Damage of the soffit of the slabs with different orientations of the bomb
Figure 21 Midspan displacement histories of the slabs with different orientations of the
bomb
Number of segments of the loading area
For each orientation, the number of segments are varied; 6 & 13 segments for the slab in
Figure 19(b) and 1, 6 & 10 segments for the slab in Figure 19(a). 10 segments were used
rather than 13 segments due to the high percentage error when reading off the fragment
impulse from the graph in Figure 12.
3m
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For the orientation in Figure 19(b), the difference in the number of segments had very little
effect on the amount of stress and z-displacement; as seen in Figure 24. The same goes for
Figure 19(a) with the exception of the slab with only 1 segment; the z-displacement is greater
than the other 2 curves, 6 & 10 segments, as seen in Figure 23. Figures 22(a) & 22(b) shows
the difference in the stress fractures of the slab in Figure 19(a) with 1 segment and 6
segments respectively.
(a) (b)
Figure 22 Damage of the soffit of the slabs with different number of affected segments
Figure 23 Midspan displacement histories of the slabs with the bomb orientation in
Figure 19(a) but different number of affected segments
Figure 24 Midspan displacement histories of the slabs with the bomb orientation in
Figure 19(b) but different number of affected segments
The z-displacement decreases as the number of segments increases due to the corresponding
reduction in the average fragment impulse. However, after a certain number of segments,
there is almost zero change in the z-displacement; a graphical plateau. This probably explains
the results mentioned above.
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CONCLUSION
From the results and the data from the simulations, we can conclude that the combined blast
and fragment loading does more damage to the RC slab than blast loading alone. The earlier
section on blast loading has also showed that by adding more rebars and having fixed
supports, the RC slab can absorb more damage from loading and deflects less than an
ordinary RC slab.
However there are still areas of improvement for this research such as the software used.
Only LS-DYNA and PrePost were used in this research thus it is unknown if other
computations will yield similar results due to the different equations they use for calculations.
In addition, only Grade 35 Concrete and Grade 460 Rebars were used thus the responses for
other grades of concrete and rebars against loading were not covered by this research.
ACKNOWLEDGEMENTS
I would like to thank my mentor Kang Kok Wei from Defence Science and Technology
Agency (DSTA) for his guidance and support throughout this attachment as well as teaching
me information and concepts of explosive as well as material engineering. I would also like
to thank the other DSTA and YDSP people for showing me what the DSTA does and what its
family enjoys as well as given me this meaningful research opportunity.
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REFERENCES
1. WIKKI, Consultancy and Software Development in Computational Continuum
Mechanics Image Source: http://wikki.gridcore.se/oldstuff/expertise-in-complex-physics
2. StudyBlue, Structures at New Jersey Institute of Technology Image Source:
https://www.studyblue.com/notes/note/n/structures/deck/6636267
3. Research Online, University of Wollongong, The state of the art of explosive loads
characterisation, 2007, pg 12, Image Source:
http://ro.uow.edu.au/cgi/viewcontent.cgi?article=7176andcontext=engpapers
4. Langberg, H, Kasun III – External Charges, Presentation in Klotz Group Fall 2008
Meeting, 2008
5. Hutchinson, M. D, Combined Blast and Fragment Impulse – A New Analytical
Approach. Military Aspects of Blast and Shock. Bourges, France, 2012
6. Hutchinson, M. D, The Escape of Blast from Fragmenting Munitions Casings.
International Journal of Impact Engineering, 185-192, 2009
7. Hartmann, T, and Rottenkolber, E, The Trouble with Cased Explosives in the
Determination of Design Loads for the Structural Analysis. Design and Analysis of
Protective Structures. Jeju, Korea, 2012
8. [8] Gurney, R, The Initial Velocities of Fragments from Bombs, Shells and Grenades.
MD, USA: Army Ballistic Research Laboratory, 1943
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ANNEX
The sample of the file written by WordPad to specify values into the mesh.
*KEYWORD
$Units: kg;m;sec;Pa / (ton;mm;sec;MPa)
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*TITLE
10kg@3m Blast
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*INCLUDE
Mesh
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*CONTROL_TERMINATION
$ *ENDTIM ENDCYC DTMIN ENDENG ENDMAS
0.05 0 0.0 0.0 0.0
*CONTROL_TIMESTEP
$ DTINIT TSSFAC ISDO TSLIMT DT2MS LCTM ERODE MS1ST
0.0 0.67 0 0.0 0.0 0 0 0
$ DT2MSF DT2MSLC
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ DATABASE CONTROL FOR BINARY $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*DATABASE_BINARY_D3PLOT
$ *DT/CYCL LCDT BEAM NPLTC
0.001 0 0 0
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*PART
Concrete
$ *pid *secid *mid eosid hgid grav adpopt tmid
1 1 1 0 0 0 0 0
*PART
Rebar
$ pid secid mid eosid hgid grav adpopt tmid
2 2 2 0 0 0 0 0
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8 1
*SECTION_SOLID
$concrete
$ *secid elform aet
1 1
*SECTION_BEAM
$rebar
$ *secid elform shrf qr/irid cst scoor nsm
2 1 1 1 1
$ *ts1 *ts2 tt1 tt2 nsloc ntloc
0.025 0.025 0 0
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
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$ MATERIAL CARDS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*MAT_Concrete_Damage_Rel3
$concrete
$ *MATID *RO PR
1 2300 1.900E-01
$ f't *A0 A1 A2 B1 OMEGA A1F
0.00E+00 -40E+06 0.00E+00 0.00E+00 0.000 0.00 0.00E+00
$ sLambda NOUT EDROP *RSIZE *UCF LCRate LocWidth NPTS
0.00E+00 0.00E+00 0.00E+00 39.37 145E-06 7201 0.00E+00 0.00e0
$ Lambda01 Lambda02 Lambda03 Lambda04 Lambda05 Lambda06 Lambda07
Lambda08
0.00E+00 0.00E+00 0.0E-00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00
$ Lambda09 Lambda10 Lambda11 Lambda12 Lambda13 B3 A0Y A1Y
0.00E+00 0.00E+00 0.000e0 0.000e0 0.000e0 0.00E+00 0.00E+00 0.00E+00
$ Eta01 Eta02 Eta03 Eta04 Eta05 Eta06 Eta07 Eta08
0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.000E+0 0.00E+00 0.00E+00 0.00E+00
$ Eta09 Eta10 Eta11 Eta12 Eta13 B2 A2F A2Y
0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.000E+0 0.00E+00 0.00E+00 0.00E+00
*MAT_PLASTIC_KINEMATIC
$steel
$ *MID *RO *E PR *SIGY ETAN BETA
2 7850 200E+09 0.30 460E+06 0.00 0.0
$ SRC SRP FS VP
30 5
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ DIF CURVE CARDS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*DEFINE_CURVE
$ LCID SIDR SFA SFO OFFA OFFO DATTYP
7201 0 1.0 1.00
$ Strain-Rate Enhancement
-3.000E+04 1.085E+01
-3.000E+02 1.085E+01
-1.000E+02 7.526E+00
-3.000E+01 5.038E+00
-1.000E+01 3.493E+00
-3.000E+00 2.338E+00
-1.000E+00 1.621E+00
-1.000E-01 1.496E+00
-1.000E-02 1.380E+00
-1.000E-03 1.273E+00
-1.000E-04 1.175E+00
-1.000E-05 1.084E+00
0.000E+00 1.000E+00
3.000E-05 1.000E+00
1.000E-04 1.035E+00
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1.000E-03 1.105E+00
1.000E-02 1.180E+00
1.000E-01 1.260E+00
1.000E+00 1.345E+00
3.000E+00 1.388E+00
1.000E+01 1.436E+00
3.000E+01 1.482E+00
1.000E+02 2.214E+00
3.000E+02 3.193E+00
3.000E+04 3.193E+00
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ BLAST LOAD CARDS (pressure) $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*LOAD_BLAST
$ *wgt *x0 *y0 *z0 tbo *iunit *isurf
10 1.50 0.50 3.2 0.0000 2 2
$ cfm cfl cft cfp death
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*LOAD_SEGMENT_SET
$ *ssid lcid sf at dt
1 -2
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*DEFINE_CURVE_TITLE
Dummy Curve for LOAD_BLAST
$ lcid sidr sfa sfo offa offo dattyp
66 0 0.000 0.000 0.0 0.0 0
$ abscissa (time) ordinate (value)
0.000000E+00 0.000000E+00
1.000000E+05 0.000000E+00
*DEFINE_CURVE_TITLE
Dummy Curve for LOAD_BLAST
$ lcid sidr sfa sfo offa offo dattyp
67 0 0.000 0.000 0.0 0.0 0
$ abscissa (time) ordinate (value)
0.000000E+00 0.000000E+00
1.000000E+05 0.000000E+00
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ BOUNDARY CARDS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*BOUNDARY_SPC_SET
$Pinned
$ nsid cid dofx dofy dofz dofrx dofry dofrz
1 0 1 1 1 0 0 0
*END
0.12m