Task NA 3.6
Preparatory Course on Seismic Qualification
Bristol, 11-12 January 2011
Introduction to seismic qualification
Prof Colin Taylor, University of Bristol
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
The presentation
Why seismic qualification?
Origins and characteristics of earthquakes
Structural response to earthquakes
The seismic qualification process
▫ Test specifications
▫ Required Response Spectra (RRS) and Test Response Spectra
(TRS)
▫ Project documents
▫ Test equipment and instrumentation
▫ Exploratory tests
▫ Seismic tests
▫ Functional test
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Sichuan, China, 12 May 2008
AP Photo/Kyodo News/Takanori Sekine
AP Photo/Kyodo News/Takanori Sekine
70,000+ dead
3 million homeless
AP Photo color/China Photo
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Interior of Apartment Building
SERIES Training Course - Bristol, Jan 11-12 2011
From http://www.smate.wwu.edu/teched/geology/eq-CA-Northridge1.html
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Interior Damage to Schools
From http://www.smate.wwu.edu/
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Damage to Shelving and Storage
From http://www.theberkeleygraduate.com/2009/10/preparing-for-an-earthquake/
From http://www.cfht.hawaii.edu/EARTHQUAKE/PHOTOS/IMGP0723_library1.JPG
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Sichuan – 12 May 2008
Source: USGS
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Sichuan – 12/05/08 event & aftershocks
Source: USGS
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Sichuan – thrust fault
Source: USGS
Source: USGS
Source: USGS
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Northridge, California, Earthquake, 1994
24 Hour Seismogram
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
UK strong ground motion
Synthetic UK hard rock ground acceleration
scaled to 1g PGA
15
Accel / ms-2
10
5
0
-5
-10
0
1
2
3
4
5
6
7
8
Time / s
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Seismic response
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Elastic structural dynamic response
Mode 1
Mode 2
Mode 3
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
MDOF simulation and secondary structure
response
4-storey with quake and tmd v8 090910.ds
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Relative
displacement x(t)
Dynamic models
Mass (m)
Damping
(c)
• Natural frequency and period
k
ω=
rad / s
m
T=
• Mass - m
• Stiffness - k
• Damping – c
• Displacement - x
• Equation of motion
2π
ω
Ground
displacement
xg(t)
seconds
Internal
inertia
force
Stiffness
(k)
Internal
damping
force
Internal
‘stiffness’
force
External
(earthquake)
force
m&x& + cx& + kx = P(t ) = − m&x&g
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Elastic response
single elastic and single plastic with elastic tmd 240310.ds
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Elastic response
El Centro, USA (May 1940), 270deg
Total Accel. (m/s/s)
10
T=0.2s
5
0
-5
peak = 6.51m/s/s
-10
0
10
20
30
time (s)
40
50
60
Total Accel. (m/s/s)
10
T=0.5s
peak = 8.34m/s/s
5
0
-5
-10
0
10
20
30
time (s)
40
50
60
Total Accel. (m/s/s)
10
T=1.0s
peak = 5.07m/s/s
5
0
-5
-10
0
10
20
30
time (s)
40
50
60
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Elastic acceleration response spectrum
Acceleration Response Spectrum
9
8
Peak Total Accel.(m/s/s)
7
6
8.34
5
6.51
4
3
5.07
0
0.1
0.2
0.3
0.4
0.5
Period T (s)
0.6
0.7
0.8
0.9
1
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Design response spectrum
4.5
4
A Design Spectrum
Peak Total Accel.(m/s/s)
3.5
3
2.5
2
1.5
1
0.5
0
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Period T (s)
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
What is Seismic Qualification?
One of many types of tests used to verify that a specimen can function under a range of
environmental conditions
▫ Shake the specimen with representative earthquake loads
▫ Numerical analysis
▫ Reference to previous test database
Other environmental tests include:
▫ Air temperature – High, Low, Change
▫ Air – Pressure, speed
▫ Humidity Range: Dry to Wet – especially for outdoors equipment
▫ Water – Rain, ice & frost
▫ Radiation – Solar , heat
▫ Mechanical substances – Dust, sand
▫ Chemical substances – Sulphur, chlorine, nitrogen, hydrogen fluoride, ozone
▫ Flora and Fauna – Micro organisms, rodents, insects
▫ Shock Loading – High g tests (up to 400g) normally by drop test
▫ Office vibration – 1-100Hz sine sweeps 30 mins / sweep
▫ EMC tests – Radio, microwave interference
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Who needs Seismic Qualification?
Nuclear Industry
▫ Power stations
▫ Submarine bases
Telecoms Industry
▫ Equipment (cabinets and contents)
x for installation in Europe / USA / Japan / Taiwan etc.
Engineering Consultancies
▫ Validation of FE analysis
x e.g. non-linear dynamic contact elements
Engineering Contractors
▫ Testing of new materials / construction techniques
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Test Specifications
BELLCORE – NEBS
NEBSTM Requirements: Physical Protection
Telcordia Technologies Generic Requirements
GR-63-CORE Issue 2, April 2002
IEC 60068-2-57
International Test Standard
Environmental testing –
Part 2-57: Tests – Test Ff: Vibration – Time-history method
ETSI EN 300 019-2-3 V2.2.2 (2003-04)
European Standard (Telecommunications series)
Environmental Engineering (EE); Environmental conditions and
environmental tests for telecommunications equipment; Part 2-3:
Specification of environmental tests; Stationary use at weather
protected locations
IEEE-87
Custom – British Energy
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Telcordia Earthquake Zone Map
From GR-63-CORE Issue 2, April 2002
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
GR-63-CORE Response Spectra
From GR-63-CORE Issue 2, April 2002
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
GR-63-CORE Response Spectra
From GR-63-CORE Issue 2, April 2002
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Develop specific secondary response spectra
Typically from dynamic FE analysis of building system
Calculate floor time history response and response spectra
Rules for idealising shape of spectra
▫ Peak broadening
▫ Enveloping
▫ etc
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Typical Test Sequence
Preliminary meetings to agree test specification including:
Equipment requirements
Main test spectra
Number and amplitude of shakes
Exploratory test requirements
Details of functions testing
Preparation of test documentation – QP, TMS
Generate shakes ready for testing
Arrival of specimen, examination for transport damage
Mount specimen on shaking table
Install instrumentation
Functional tests
Exploratory tests
Functional tests
Main seismic tests including basic data processing
Functional tests
Remove specimen from shaking table and return to client
Final data processing and produce test report
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Requirements of Test House
Necessary testing equipment – shaking table
Additional equipment – power (3 phase), air line, water etc.
Calibrated Instruments
A fully operating QA system
Skilled operators
Within the University of Bristol BEELAB performs this role
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Test Equipment – Shaking table
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Project Documentation
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Calibration Certificates
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SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Typical Test Specimens
• Electronics
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Mounting Arrangements
• Mounted as will be installed on site
• Both location and style of connection
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Instrumentation
Acceleration:
Shaking table: 3 axis
Specimen Top: 3 axis
Specimen mid height : 3 axis
Displacement:
Specimen Top: 2 axis
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Exploratory Tests
To ascertain main frequencies of test item
Use random excitation or sine sweeps. Excitation levels predefined
Results may be used to modify main test sequence
Results for a telecoms cabinet ( X and Y axes)
Main Natural Frequency: 9.8 Hz
Damping: 2.4 %
Main Natural Frequency: 8.5 Hz
Damping: 2.6 %
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Exploratory Tests
• Sine sweep test data
• In-house processing of results
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Functional Tests
To confirm test item operates after (and during) a seismic event
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Typical Shake Sequences
Triaxial Shakes:
25%, 50%, 75%, 100%, 140% (and back down)
5 at 25%, 1 at 100%, 1 at 140%
5 at OBE, 1 DBE, 1 SSE
Other combinations are possible
Shakes more than 100% are used to check for “cliff edge” effects
2.00
1.50
Single Axis Shakes:
BELLCORE
100% each axis
1.00
0.50
0.00
0
5
10
15
20
25
30
-0.50
-1.00
Zone 4 accel (g)
-1.50
Zone 2 accel (g)
-2.00
Time (s)
SERIES Training Course - Bristol, Jan 11-12 2011
35
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Signal shaping
Prescribed time history
▫ E.g. Bellcore
▫ Adjust table control to fit table motion to prescribed history within allowed
tolerances
Generate synthetic table time history that envelopes Required Response
Spectrum
▫ At key frequencies (e.g. 1/3rd octave)
▫ Iterative approach
▫ Statistical independence of motions
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Typical Test Specimens
• Telecoms, Mechanical Equipment
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Typical Test Specimens
• Subsea unit for oil well Xmas tree - Operation and Transportation tests
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Typical Test Data
X axis - Run 1 Failed to envelope
X axis - Run 2 Enveloped
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
Example Test
Horizontal BELLCORE shake
SERIES Training Course - Bristol, Jan 11-12 2011
SEISMIC ENGINEERING RESEARCH INFRASTRUCTURES FOR EUROPEAN SYNERGIES
SERIES Training Course - Bristol, Jan 11-12 2011