National Student Leadership Conference
Engineering Section - Summer 2006
Session 3: July 16-26
Live Video Cameras in the Lab
The local telepresence system features several cameras in the lab
showing experiment locations.
This provides several live views of laboratory activities
that can be accessed with a web browser.
In addition, one can capture still images from the live video stream.
Click on this link below
to view the streaming images from those cameras.
Live Video
Cameras in the NEES Lab.
Agenda, Datas, Photos and Videos
All of these activities took place at the nees@berkeley Equipment Site located at the UC Berkeley Richmond Field Station in Richmond, California.
| July 17 Monday 14:00–17:30 |
| 14:00 |
Welcome and Introduction.
Khalid M. Mosalam |
| 14:10 |
Earthquakes: Overview and Wood Houses Case Study, Part 1.
Khalid M. Mosalam |
| 14:40 |
Visit laboratory, discuss plans for small-scale wood panel test and demonstration of a cyclic test on a small-scale wood panel.
Graduate Students and Staffs |
| 15:10 |
Form Groups A and B for laboratory activities.
Graduate Students and Staffs |
| 15:20 |
Break. |
| 15:30 |
Station activities: Group A for axial tests and Group B for constructing panels, including safety tips.
Graduate Students and Staffs |
| 17:30 |
Adjourn for Day 1. |
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| Listening to lectures in the classroom. |
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Demonstration cyclic test on a wood wall specimen. |
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| Building wood wall specimens for testing. |
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Axial load testing uses the small press. |
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| July 20 Thursday 14:00–17:30 |
| 14:00 |
Introduction.
Khalid M. Mosalam |
| 14:10 |
Earthquakes: Overview and Wood Houses Case Study, Part 2.
Khalid M. Mosalam |
| 15:00 |
Visit earthquake simulator (shaking table).
Graduate Students and Staffs |
| 15:20 |
Break. |
| 15:30 |
Station activities: Group A for constructing panels and Group B for testing their panels.
Graduate Students and Staffs |
| 17:30 |
Adjourn for Day 2. |
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| Listening to this day's lecture. |
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Touring the shaking table facility. |
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| Building wood wall specimens for testing. |
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Testing the wood wall specimens. |
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| July 25 Tuesday 14:00–18:00 |
| 13:30 |
Introduction and demonstration of large-scale double wood panel in nees@berkeley Equipment Site, including visit the control room and watch videos of previous shaking table experiments.
Graduate Students and Staffs |
| 14:20 |
Break. |
| 14:30 |
Station activities: Group A for testing their panels and Group B for axial tests.
Graduate Students and Staffs |
| 17:00 |
Student presentations. |
| 17:30 |
Adjourn for Day 3. |
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| Large-scale test on wood wall — side view. |
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Large-scale test on wood wall — end view with actuator above. |
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| Reviewing the results of testing the student-built panels. |
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Students giving presentations. |
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Axial Load Tests
The students learn engineering properties of common materials used in construction,
wood and concrete. At this station the students perform compression test to concrete cylinders,
wood pararel to grain and wood perpendicular to grain. For each test, the students draw
stress strain curves and compute the modulus of elasticity of the materials. The modulus of elasticity
is an engineering property that relates the deformation of a material when it is subjected to forces.
The stress-strain curves and final results from these experiments
are shown in the charts and tables below.
These show the results for each of the two groups.
Tests of Constructed Panels
The students perform a monotonic test
on 4-foot by 4-foot wood panels that they construct.
A monotonic test consists of applying an increasing lateral load
to the panel until it reaches the maximum strength.
The students build panels with three different configurations
using different nailing patterns, stud spacing, and type of wood panelling.
For each panel, they determine the maximum strength
and they identify the failure mode.
Comparing the results of panels with different configurations,
the students learn how these configurations
can affect the behavior of these panels.
Experiments like these provide information
for engineers and builders
so that they can design houses
that are more resiliant and better able to survive earthquakes.
The panel construction
starts with a frame of 2-inch by 4-inch (2x4) Douglas-Fir structural wood.
Most frames have 4 vertical studs spaced at 16 inches.
The studs are toe nailed to the bottom plate
and end-nailed to the top plate with 16d nails.
The coverings are nailed to the frame with 8d nails.
The variations are as follows:
Group 1: Covered specimen
with one 4-foot by 4-foot sheet of half-inch plywood
using 12-inch nail spacing.
In addition, they used two extra nails
on each corner of the panel
Group 2: Covered specimen
with shiplap boards,
using 3 nails on each board where it crosses a stud.
For this specimen, the top shiplap board
is not nailed to the top plate
(but the bottom shiplap board is nailed to the bottom plate).
Group 3: Covered specimen
with shiplap boards,
using 3 nails on each board where it crosses a stud.
For this specimen, both the top shiplap board is not nailed to the top plate
and the bottom shiplap board is not nailed to the bottom plate.
The chart below shows
the Force-Deformation curves
of the wood panels constructed by the students.
The table below summarizes
the maximum strength of the panels
and the displacement at which this maximum strength is attained.
| Group and Test |
Specimen |
Force
kips |
Displacement
inches |
Videos |
| G1: | 1 Plywood Sheet (4-foot by 4-foot) and 12-inch Nail Spacing with Extra Nails in Corners |
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Video |
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Video |
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Video |
| G2: | Shiplap with 3 Nails, Not Connected to Bottom Plate |
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Video |
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Video |
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Video |
| G3: | Shiplap with 3 Nails, Not Connected to Top or Bottom Plates |
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Video |
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Video |
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Video |
| Notes |
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*
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The maximum strength of the shiplap
was not reached in the experiment
because the deformation capacity of the actuator
was reached before the maximum strength.
The values shown in the table
respresent the strength at a displacement of about 5 inches.
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4x4 Cyclic Demo
The students observe a cyclic demo
on a 4-foot by 4-foot wood panel specimen.
The panel is constructed
with studs at 12-inch spacing
and covered with two two-foot by four-foot plywood sheets.
The plywood is nailed to the frame using 12-inch nail spacing.
The panel is subjected
to 0.5-inch amplitude cycles and 3.5-inch amplitude cycles.
The force deformation curve of this demo
is shown in the next figure.
Video: Cyclic test of wood panel
Full-Scale Demo
The students will watch a full-scale wood demo in the NEES lab.
The demo consists of a pseudodynamic test
of two parallel wood walls measuring 234 inches by 102 inches (19.5 feet by 8.5 feet)
connected at the top with a steel frame.
The gravity load of the system is achieved with 3 vertical rods
that connect the steel frame with the floor.
The pseudodynamic test is done
using two consecutive Loma Prieta earthquake records
scaled to 0.66 g.
The figures below show the displacement and force versus time.
The figure below shows the force-deformation relation measured in the test.
Experiment Data
These data may include
numeric data from various measuring instruments
and image data from cameras, both still and video.
Numeric Data.
Files of numeric data are ASCII files in a tab-separated value format.
These files can be opened with text editors (eg Windows NotePad or WordPad)
and spreadsheets (for example Windows Excel or OpenOffice Calc).
Still Image Data.
Still image data are usually JPEG files.
These files may be viewed with most graphical web browsers
(for example Windows Internet Explorer, Mozilla, Firefox)
as well as photo viewing and editing applications
(for example Adobe Photoshop).
Video Data.
Video data are usually some form of Windows AVI files.
These videos can be viewed with Windows Media Player.
