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Module 1 - Building Vibrations and Earthquake Response
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WORK STILL TO DO ON TUTORIAL: CLICK HERE
Introduction
In this lab module, you will learn about the dynamics and vibrations of buildings through video, computer simulations, and physical experiments.
You will learn how to mathematically describe the dynamic behavior of a three-story building in terms of how the building will respond and oscillate during an earthquake.
For a three-story building, you can model the vibrations of the building using a system of three differential equations, similar to the spring-mass-damper type that you studied in your freshman physics course (for an online tutorial of the former, in case you have forgotten what you've learned, go here).
The key difference between the single-mass system you studied then, and the three-mass system you will study here, is that the three equations used in the three-mass system are inter-related, or coupled.
Physically, this means that the response and oscillations of one floor mass depends on the oscillations of the other floors.
In coupled systems it is often convenient to write the differential equations in terms of matrices.
Matrix notation helps us simplify and unify how we mathematically describe dynamic systems, like this three-story building.
This module is designed to help you in the process of understanding the dynamic response of buildings, how they are modeled mathematically, and how their response is measured experimentally.
The ultimate goal is for you to learn how predict experimental response based on the model's parameters.
In order to accomplish this task, this module provides you with a detailed tutorial, a computer simulator, the physical experiment, and associated videos.
After completing this module, please take some time to complete our anonymous evaluation questionnaire for this WEAVE module.
Before continuing, please note the time.
When you fill out the questionnaire, you will be asked how much time you spent working on this web-based lab.
Module Steps
The tutorial will help you complete these five steps:
- Part I: Interactive Tutorial.
- View videos of shaking building models and walk through an interactive tutorial that describes the vibration analysis of multi-story buildings.
- Part II: Run the Computer Simulation.
- Explore the effects of changing the stiffness, damping, and the forcing function in the numerical model.
- Plots of the computed accelerations of each floor are generated every time you run the simulation.
- Part III: Run the Physical Experiment.
- A small-scale three-story building model with a base actuator is set up in Hudson Hall.
In this part, you will launch this experiment remotely over the web.
- Run experiments with pre-chosen parameters and view the
associated videos.
- Try different input parameters and forcing functions.
- Plots of the measured accelerations of each floor are generated every time you run the experiment.
- Part IV: Run Both Simulation and Experiment Side by Side.
- Estimate the inter-story stiffness and damping from the miniature experimental model results.
- Tune the simulation parameters until you obtain a good match to the experiments.
- Part V: Module Completion and File Submission.
- Complete the module evaluation questionnaire.
Click here to begin: Part I - Tutorial.