National Student Leadership Conference
Engineering Section — Summer 2006
Session 2: July 02–12
Agenda, Datas, Photos and Videos
All of these activities took place at or near the nees@berkeley Equipment Site
located at the UC Berkeley Richmond Field Station in Richmond, California.
| July 02 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 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 Staff |
| 15:10 |
Form Groups A and B for laboratory activities.
Graduate Students and Staff |
| 15:20 |
Break. |
| 15:30 |
Station activities: Group A for axial tests and Group B for constructing panels, including safety tips.
Graduate Students and Staff. |
| 17:30 |
Adjourn for Day 1. |
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| Conducting tests using axial compression. |
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Crushed concrete specimen. |
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| Building wood wall specimens for testing. |
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American Idol: Who is on the live cameras? |
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| July 11 Tuesday 14:00–18:00 |
| 14:00 |
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 Staff. |
| 14:50 |
Break. |
| 15:00 |
Station activities: Group A for testing their panels and Group B for axial tests.
Graduate Students and Staff. |
| 17:30 |
Student presentations. |
| 18:00 |
Adjourn for Day 3. |
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| Full-scale specimen is wood wall at right. |
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Interesting point in the full-scale demo. |
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| Students giving presentations. |
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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.
For panels that are covered with two half-pieces of plywood,
the frame uses 12-inch stud spacing.
The studs are toenailed 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 two 2-foot by 4-foot sheets of half-inch plywood
using 6-inch nail spacing.
- Group 2: Covered specimen
with shiplap boards,
using 2 nails on each board where it crosses a stud.
- Group 3: Covered specimen
with shiplap boards,
using 3 nails on each board where it crosses a stud.
The chart below shows the Force-Deformation curves
of the 6 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.
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 16-inch spacing
and covered with one 4-foot by 4-foot plywood sheet.
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.
Additional datas:
data2006_07_03_01.txt & data2006_07_03_02.txt
Video: Cyclic Test of Wood Panel
Full-Scale Demo
The students 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.
Video: Big wall demo
The figure below shows 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.
