National Student Leadership Conference
Engineering Section - Summer 2006
Session 1: June 18–28
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.
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.
Test 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.
The frames have 4 vertical studs spaced at 16-inches
and connected to the bottom and base plate with 16d nails.
The plywood is 1/2" thick and nailed to the frame with 8d nails.
The variations are as follows:
- Group 1:
End nailing the frame and
6-inch nail spacing for the plywood panel.
- Group 2:
End nailing the frame and
12-inch nail spacing for the plywood panel
- Group 3:
Toenailing the frame and
6-inch nail spacing for the plywood panel.
The chart below shows the Force-Deformation curve
of the nine 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 6-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: data 01_06_19_2006 & data 02_06_19_2006
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 cyclic 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 cyclic test is done incrementally
up to a maximum displacement of 10 inches.
Data: demo01run034_Cyclic_Curee.txt
Video:
Big wall demo
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.
