The NEES team partnered with the Engineering Projects in Community Service (EPICS) program to design and build engaging demonstrations to illustrate the engineering and scientific advances resulting from NEES research.
The NEES-EPICS team consisted of engineering students at Purdue University interested in designing educational technologies to encourage teaching of science, technology, engineering, and mathematics (STEM) within an earthquake engineering context.
Their primary project was a low-cost instructional shake table capable of demonstrating scientific concepts of force and motion and engaging learners in the practice of engineering design.
Servo-Controlled Instructional Shake Table
The Network for Earthquake Engineering Simulation (NEES) needed a portable and controllable shake table for use in schools to teach science and engineering and for use in public demonstrations to teach people about NEES earthquake engineering research. The student team developed an inexpensive, yet accurate shake table to fulfill learning goals of educators in universities, K-12 schools, and free choice learning environments like museums and science fairs. The cost of the shake table is under $1,000, an affordable price for educational institutions.
The instructional shake table system consists of a uni-axis motion-controlled shake table and control box. With these two devices a user can manually specify harmonic motion of the table platform by selecting the amplitude and frequency. The system includes software to interface a personal computer with the control box to provide additional operating modes and gather sensor data. The sensor data plots in real time on the computer screen and can be simultaneously projected in a classroom. Sensor data also can be saved for later use.
Manual Shake Table
A second project of the NEES-EPICS team was the manually controlled shake table that can be built for an even lower cost, under $100, to support useful educational activities and demonstrations. The vision was for teachers to build their own tables with parts from a local hardware store. In addition to written plans, the team recorded a video tutorial for the assembly of the manual shake table. The short 10 minute video documents the list of parts, the tools needed, and how to put together the shake table.
Both the servo-controlled and manually controlled instructional shake tables have a wide range of instructional applications to teach principles of engineering and explore physical properties of systems. For example, K’NEX (plastic toy construction kits) can be used to construct scale models of tall buildings like the ones shown in the figure below. When shaken on the table the motion of the tall buildings can illustrate concepts such as fundamental period and resonance. Then one building can be modified with one of many engineering solutions that limit damage caused by an earthquake. The side-by-side comparison with an unmodified tower provides a strong visual of the difference between the two constructed towers. These engineering solutions include, but are not limited to, cross bracing, tune mass dampers, passive damping, base Isolation, and shear walls.
Also, these units can be used to meet many science standards through experiments that illustration basic physics principles. Examples include natural frequency, resonance, and the effect of mass on a dynamic system, acceleration, momentum and properties of materials. Lesson plans for these activities are found here.
Finally, the design challenges in the shake table lessons provide K-16 students learning experiences that are intellectually engaging, increase student interest in science and engineering, and meet the Next Generation Science Standards. For example, a teacher can introduce students to basic earthquake engineering principles and discuss how geoscientists measure magnitude and intensity with seismometers using the shake tables to simulate the events under controlled conditions. Then they can engage students in engineering design practice by constructing structures and testing them on the shake tables much like NEES researchers. An example of this type of challenge is found here.