National Business ParkBuilding 300
300 Sentinel Drive
Annapolis Junction, MD
20701
BLAST DESIGN AND
ANALYSIS
Rebecca Dick
Structural Option BAE/MAE
Dr. Memari
Spring 2012 Senior Thesis
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
National Business ParkBuilding 300
•212,000 sq. ft
•Composite steel construction
•7 story office building
•Located in an industrial park in Annapolis Junction,
Maryland (about halfway between Baltimore
and Washington D.C.)
•Cost: $38 Million
•Construction Dates: March 2008-July 2009
N
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
National Business ParkBuilding 300
Original Members:
Exterior Columns: W14x99
Interior Columns: W14x159
Beams Between Columns: W27x102
Infill Beams: W27x94
Exterior Girder: W27x102
Interior Girder: W27x84
Slab: 3” 20Gage (composite) Metal Deck
w/
3.5” LWC topping
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Thesis Goals
•Design a typical bay for blast
•The basis of this design is that the owner may be
renting to government agencies from the nearby
D.C. area and wants above average protection
•Column, Beam, Girder, Slab, Moment Connection
•Model the redesign In LS-DYNA to verify results
•Use LS-DYNA to show that a partial building model is
sufficient for blast analysis (3 bay by 3 bay, 3
story heights)
•Complete a Site Redesign (Breadth Topic I)
•Complete a Façade Redesign and check heat transfer
through façade (Breadth Topic II)
Site Redesign
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
N
Original Site
N
Redesigned
Site
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Site Redesign
N
Redesigned
Site
Site Security Alternatives:
• Decorative Boulders
• Bollards
• Wrought Iron Gate
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Blast Load Determination
BLAST LOADING
Explosive Compound:
Weight of C-4:
Equivalent
117 Mass
psi for Pressure:
Equivalent Weight of TNT:
R=
C-4
50
1.37
36.5
15
Scaled Distance:
Peak Overpressure:
Peak 21
Reflected
psi Pressure:
4.5
50
117
ft/lb1/3
psi
psi
Reflected Impulse:
Effective Duration:
269
4.6
psi-ms
ms
Gas Pressure Loading Density:
Peak Gas Pressure:
lb
lb
ft
0.0017 lb/ft3
21
psi
Scaled Gas Impulse:
123
psi-ms
Gas Pressure Effective Duration:
25.6
ms
Blast Design
• Consider both impact from the initial blast wave
and additional time-dependent pressures
• Blast assumed to occur at center of bay
• Space will vent at 5 psi
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Blast Load Determination
• Limitations on ductility ratio and support
rotations to ensure no connection failures
(taken from the UFC 3-340-02 for occupant
protection)
• Increased yield stresses (71 ksi)
• 1.0B+1.0D+0.25L
• Iterative process- initial members were chosen
based on required section properties and
upsized if they didn’t meet rotation/ductility
requirements
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Column Design
Assumptions:
• Distributed Blast Pressure only on Flange of
Member
• Peak Reflected Pressure (117psi) used to account
for close radius blast load (ie, blast directly next
to column base) and to account for non-linear
loading along column height
• W14x159
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Beam and Girder Designs
Assumptions:
• Distributed Blast Pressure only on Flange of
Member
• 21 psi Gas Pressure design load- most critical
because long duration
• W27x161 Beam
• W30x116 Girder
Beam Stress Profile
Girder Stress Profile
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Slab Design
#8 @ 18” O.C.
T&B E.W.
METAL FORM
DECK
(SHORED)
Blast Pressure wave hitting
underside of slab in Lobby Bay
W27x161
BEAM
Assumptions:
•Initial design consisted of slab on shored form
deck, but found to be uneconmical (system depth,
constructability)
•Difficult to design a floor system that is both
economical and sustains little damage
•Slab not a critical element so damage is allowed
(spalling, cracking, failure)
•Final design consisted of 3VLI16 composite deck
with
4.5” concrete
•Research
into topping
Aluminum Foam
Composite
Sandwich Panels
Distribution of Stress in Slab at 15 ms
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Moment Connection
Assumptions:
• AISC Seismic Design Requirements
• Must allow full plasticity of connecting
member to develop
• No overstrength factors for connections
• 8ES Prequalified Connection
Exterior Beam to Column
Moment Connection Location
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
LS-DYNA Model
• Finite Element Analysis Software
• Developed by Livermore Software
Technology Company (LSTC)
• Uses First Principle Method of
analysis to determine blast load
and effects
• Used in automotive design, IED
blast on tanks, ect.
NOTE: LS-DYNA was used only as
an analysis tool, not for design
purposes. All designs were
completed through hand calculations.
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
LS-DYNA Model
Framing of Partial
Model without Slab
Indices Used to Create
Wide Flange Shape
Framing of Partial
Model with Slab
Interior Column with Beams Framing
into it from all sides- Mesh Visible
•Girders and Infill beams above 50
ksi Static Yield Limit
•All other members have very low
maximum stresses
Von Mises Stress (psi)
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
LS-DYNA Model
Time (ms)
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
LS-DYNA Model
A Further Look:
• Change in x-length vs.
time (graph on far
right)
• Based on defined
original line (figure to
right)
• Curvature assumed to
be constant
• Rotation determined
to be .03 degrees<< 2
degrees
28.301”
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
•Blast force minimal in
directly adjacent bays
at 20ms
•Stresses in members
beyond blast bay are
minimal (with the
exception of the
girders)
•Girders are
experiencing rotation
and displacement from
odd framing conditions
LS-DYNA Model
Blast Pressure Wave at
20 ms
Stress Profiles of all Elements
Modeled at 20 ms
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Façade Redesign
•Designed to resist design wind loads
•Designed using top anchor system and will
fail at 5psi
•Two lites of ¼” Fully Tempered Glass in IGU
•Top anchor gaskets and SSG for blast will
be used to hold top in place while
other three sides will be dislodged from
mullion supports
•8 mil safety film used to attach glazing to
top anchor at the interior
Exterior
Horizontal
Mullion
½” Clearance
Space
2 Lites ¼” FT
Glass
Separated by
3/8” Air Space
Interior
Mullion and
Anchor Plate
GlassLock
Anchor
GlassLock Wedge
Gasket w/ ½”
UltraGlaze SSG4000
Sealant
8 mil Safety Film
Anchored at Top
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Conclusion
•Site redesigned to provide security and safety
•Hand calculations yielded members sufficient to
withstand blast
•Analysis in LS-DYNA proved redesigned structure to
have stresses below dynamic yield
•Analysis in LS-DYNA also showed that blast
pressures not critical in far bays as the
pressure barely reaches adjacent bays so
partial model is adequate
•Façade Redesigned to ventilate interior but glazing
restrained to maintain safety of occupants
•Building
Introduction
•Thesis Goals
•Site Redesign
Breadth
•Blast Design
•LS-DYNA
Modeling
•Façade
Redesign
•Conclusion
Acknowledgements
Thank you to the Penn State Faculty:
A very special thank you Dr. John O. Hallquist, President,
Livermore Software Technology Corporation (LSTC), and
Marsha J. Victory, President, FEA Information Inc, for
providing me access to the LS-DYNA finite element
software for free for my senior thesis and to Gunther
Blankenhorn and Todd P. Slavik for the invaluable
technical support and troubleshooting they provided.
Dr. Memari
Dr. Hanagan
Dr. Parfitt
Ryan Solnosky
Thank you to my friends and family:
David Tran
Brian Rose
Mike Kostick
Ryan Blatz
QUESTIONS?
Hope you had a
blast!!
Winter Thermal Gradient
Component
R
R
R/RT
Room Air
Inside Air Film
0.68
0.68
1.0
Gyp Board
0.32
1
1.5
Batt Insulation
15
16
24.1
Plywood
0.62
16.62
25.0
Vapor Retarder
16.62
25.0
Air Cavity
0.68
17.3
26.1
Rigid Insulation
11
28.3
42.7
Precast Concrete
0.87
29.17
44.0
Outside Air Film
1.35
30.52
46.0
Outside Air
30.52
Winter Heat Loss
T
70.0
69.0
68.5
45.9
45.0
45.0
43.9
27.3
26.0
24.0
24.0
A=
Uconcrete=
Uglazing=
DTwinter=
DTsummer=
4575 ft2
0.0328
0.3333
46 °F
18 °F
through
concrete
through glazing
sensible heat loss(winter)-=
6895.5
70150
latent heat loss can be neglected due to high efficiency vapor
retarder
Total:
77045.5
Btu/hr
Sensible Heat Gain:
Summer Thermal Gradient
Component
R
R
R/RT
Room Air
Inside Air Film
0.68
0.68
0.3
Gyp Board
0.32
1
0.4
Batt Insulation
15
16
6.8
Plywood
0.62
16.62
7.1
Vapor Retarder
16.62
7.1
Air Cavity
0.68
17.3
7.4
Rigid Insulation
11
28.3
12.1
Precast Concrete
0.87
29.17
12.4
Outside Air Film
1.35
30.52
13.0
Outside Air
30.52
Summer- Heat Gain
T
75.0
75.3
75.4
81.8
82.1
82.1
82.4
87.1
87.4
88.0
88.0
A=
Uconcrete=
Uglazing=
DETD=
DCLF=
IF=
N=
Plights=
Pequipment=
4575 ft2
0.1700
0.81
10
56
1.1
300 people
54600 Btu/hr
9600 Btu/hr
6000 Btu/hr
10000 Btu/hr
2000 Btu/hr
computers
printers
copiers
misc.
Envelope:
Glass:
Outdoor Air:
People:
Lights
Equipment:
2567 Btu/hr
171654 Btu/hr
5033 Btu/hr
69000 Btu/hr
54600 Btu/hr
27600 Btu/hr
Total:
330453 Btu/hr
Total:
66091 Btu/hr
Latent Heat Gain:
Total Summer Heat Gain:
396544 Btu/hr
$# LS-PrePost command file created by LS-PrePost 3.2 (Beta) –
20Nov2011(14:55)
$#
cemptymodel
bmcreate multiple i 1 5 6 7 11 j 1 3 8 13 15 k 1 41 81 121
x -7.30 -0.2425 0.0 0.2425 7.30 y -7.10 -6.320 0.0 6.320 7.10 z 0 180 348 516
bmmovei i 1 5 j 1 5 k 1 4 xyz 0 76 0
bmdeletei i 1 2 j 2 4 k 1 4
bmdeletei i 4 5 j 2 4 k 1 4
bmaccept partid 1
$#
bmcreate multiple i 1 5 6 7 11 j 1 3 8 13 15 k 1 41 81 121
x -7.30 -0.2425 0.0 0.2425 7.30 y -7.10 -6.320 0.0 6.320 7.10 z 0 180 348 516
bmmovei i 1 5 j 1 5 k 1 4 xyz 360 0 0
bmdeletei i 1 2 j 2 4 k 1 4
bmdeletei i 4 5 j 2 4 k 1 4
bmaccept partid 1
$#
8 node solid element with 1
point of integration
Recommended by LSTC
All six components of stress
because continuous element
•Elements created using Block Mesh
•Each member coded individually
•Moment connections modeled using
the Tied Interface Command
•Keycards used to define blast load
•Blast detonated at 2.5ms and model
runs for 20ms
Reinforcement:
Reinforcing Bars
Welded Wire Fabric (WWF)
Lap Splices
Structural Steel:
Grade 50:
All other steel:
Bolts:
Metal Deck:
•Floors:
ASTM A615, Grade 60
ASTM A-185
ACI 318
ASTM A992, Grade 50, Fy= 50 ksi
ASTM A572, Grade 50, Fy = 50 ksi
ASTM A325, with threads included in shear
planes, 1.5” diameter
3VLI16, composite
Minimum Concrete Compressive Strengths (f'c)
Member
28 Day Strength (psi)
Elevated Slabs
4000
Slab-on-Grade
4000
Walls, Piers, and Grade Beams
4000
Interior Concrete Topping
4000
Concrete Exposed to Freezing
4000
Minimum Concrete Compressive Strengths
Live Loads
Superimposed Dead Loads
Area
Floors
Roofs
MEP
Design Load
15 psf
15 psf
20 psf
Area
Floors (including partition
load)
Mechanical Room
Elevator Machine Room
Penthouse Floor
Stairs
Slab-on-Grade
Screen Enclosure and Roof
Area
Design
Load
ASCE 7-05
Load
100 psf
125 psf
150 psf
150 psf
100 psf
150 psf
80 + 20 psf
100 psf
-
60 psf
60 psf
Snow Loads
Load Type
Roof Snow
Load
Drift Load
Design
Load
ASCE 7-05
Load
20
Not
available
17.5
81.94
COST ANALYSIS OF STRUCTURAL MEMBERS
ORIGINAL DESIGN
MEMBER
LENGTH (ft)
NUMBER OF
MEMBERS
W14X99
W14X159*
W27X84
W27X94
W27X102*
15
15
35.1
40.9
40.9
2
2
1
2
3
TOTAL COST PER
LINEAR FOOT
TOTAL W/ O&P (PER
LINEAR FOOT
$
$
$
$
$
$
$
$
$
$
142.02
225.00
120.64
133.64
144.94
158.10
252.00
134.00
149.00
161.00
TOTAL
TOTAL
$ 4,260.60
$ 6,750.00
$ 4,234.46
$ 10,931.75
$ 17,784.14
$
TOTAL W/ O&P
$
$
$
$
$
4,743.00
7,560.00
4,703.40
12,188.20
19,754.70
43,960.95 $
48,949.30
BLAST REDESIGN
MEMBER
LENGTH (ft)
NUMBER OF
MEMBERS
W14X159*
W27X161
W30X116
15
40.9
35.1
4
4
2
TOTAL COST PER
LINEAR FOOT
$
$
$
TOTAL W/ O&P (PER
LINEAR FOOT
225.00 $
225.80 $
164.77 $
TOTAL
% INCREASE FOR REDESIGNED STRUCTURE:
NOTE: Members with (*) were interpolated/extrapolated from data in RSMeans 2012
252.00
251.00
182.00
TOTAL
$ 13,500.00
$ 36,940.88
$ 11,566.85
$
TOTAL W/ O&P
$
$
$
15,120.00
41,063.60
12,776.40
62,007.73 $
68,960.00
141%
141%
A limiting support rotation of 2 degrees, and a limiting ductility
ratio of 10 (whichever governs) are specified as reasonable
estimates of the absolute magnitude of the beam deformation
where safety for personnel and equipment is required. These
deformations are consistent with maintaining structural integrity
into the plastic range.
For a beam element, the ductility ratio must be checked to
determine whether the specified rotation can be reached
without premature buckling of the member.
Under rapidly applied loads, the
rate of strain increases and this has a marked influence on the
mechanical properties of structural steel.
Considering the mechanical properties under static loading as a basis,
the effects of increasing strain rates are illustrated in Figure 5-1 and
can be summarized as follows:
(1) The yield point increases substantially to the dynamic yield stress
value. This
effect is termed the dynamic increase factor for yield stress.
(2) The modulus of elasticity in general will remain insensitive to the
rate of loading.
(3) The ultimate tensile strength increases slightly. However, the
percentage increase is less than that for the yield stress. This effect is
termed the dynamic increase factor for ultimate stress.
(4) The elongation at rupture either remains unchanged or is slightly
reduced due to increased strain rate.
Dusenberry, Donald O. Handbook for Blast-resistant Design of Buildings. Hoboken, NJ: J.
Wiley, 2010. Print.
General Electric. Cnstruction Products. General Electric, 2007. GE Construction Sealants.
GE, 2007. Web. 5 Mar. 2012.
<http://www.siliconeforbuilding.com/pdf/general/GE_Products_Catalogue.pdf>.
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Corporation, 2002. Web. 26 Dec. 2011.
<http://ftp.lstc.com/anonymous/outgoing/trent001/manuals/gettingstarted/GettingStarted.pdf>.
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Saddle River, NJ: Pearson Prentice Hall, 2007. Print.
LS-DYNA Aerospace Working Group. LS-DYNA Aerospace Working Group Modeling
Guidelines Document. 2011. Print. Version 11-1.
LSTC. BlockM Multiple Tutorial. LSTC. Web. 22 Dec. 2011.
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RSMeans Building Construction Cost Data. 70th ed. R.S. Means, 2012. 130-31. Print.
Sriram, Rajan, and Uday K. Vaidya. "Blast Impact on Aluminum Foam Composite Sandwich
Panels." Drop/Impact Simulations. Proc. of 8th International LS-DYNA Users Conference,
Dearborn, Michigan. University of Alabama at Birmingham, 2004. Web. 20 Feb. 2011.
"Standard Practice for Determining Load Resistance of Glass in Buildings." ASTM
International E-1300-04 (2004): 1-58. ASTM International, 2004. Web. 26 Jan. 2012.
"Marylanders Grow Trees." Marylanders Plant Trees. Web. 16 Feb. 2012.
<http://www.trees.maryland.gov/pickatree.asp>.
Stein, Benjamin, John S. Reynolds, Walter T. Grondzik, and Alison G. Kwok. "Thermal
Control." Mechanical and Electrical Equipment for Buildings. 10th ed. Hoboken, NJ: John
Wiley and Sons, 2006. 149-281. Print.
McCormac, Jack C. Structural Steel Design. 4th ed. Upper Saddle River, NJ: Pearson Prentice
Hall, 2008. Print.
US Department of Defence. UFC 3-340-02. US Department of Defence, 2008. 5 Dec. 2008.
Web. 30 Nov. 2011.
Geschwindner, Louis F. Unified Design of Steel Structures. Hoboken, NJ: Wiley, 2008. Print.
Le Blanc, G., M. Adoum, and V. Lapoujade. "External Blast Load on Structure- Empirical
Approach." ALE, FSI, SPH (2). Proc. of 5th European LS-DYNA Users Conference, United
Kingdom, Birmingham. 2005. 2005. Web. 22 Dec. 2011.
<http://www.dynalook.com/european-conf-2005>.
Lee, Dong Kwan (David), and Brendan J. O'Toole. "Energy Absorbing Sandwich Structures
Under Blast Loading." Penetration/ Explosives. Proc. of 8th International LS-DYNA Users
Conference, Dearborn, Michigan. Department of Mechanical Engineering at the University
of Nevada, Las Vegas, 2004. Web. 20 Feb. 2011.
Memari, Ali M., Richard A. Behr, and Paul A. Kremer. "Dynamic Racking Crescendo Tests on
Architectural Glass Fitted with Anchored Pet Film." Journal of Architectural Engineering 10.1
(2004): 5. Print.
Ngo, T., P. Mendis, A. Gupta, and J. Ramsay. "Blast Loading and Blast Effects on StructuresAn Overview." Electronic Journal of Structural Engineering (2007): 76-91. Electronic Journal
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