Reference no: EM132525621

ENG10004 Digital and Data Systems - Swinburne University of Technology

Project : Earthquake Resistant Structures

Project Description

The majority of earthquake-related deaths occur from the collapse of structured buildings. The shaking caused by the seismic waves of earthquake damages buildings and causes them to collapse. The amount of damage caused to a building is directly related to the amplitude, time frame and amount of shaking from the earthquake. Engineering techniques can be used to create a very sound structure that will withstand as much sideways motion as possible in order to minimize damage to the structure and give the occupants time to get out safely.

In this project scenario, your team is to design an earthquake-resistant tower for broadcasting and observation in a crowded city and to create a prototype of your idea. To test how earthquake-resistant your prototype really is, you will also need to build a shake table to simulate the lateral ground displacement caused by earthquake shakings.

This project is relevant to the disciplines of civil, construction, mechanical, and product design engineering.

Design Requirements

1) Follow the design steps of Engineering Design Process as provided in the Section of General Information.
2) The structure of the tower will be built out of balsa wood and strings which are supplied in the project kit. No other components are allowed.
3) The area of the base of the tower must not exceed 225cm2 and the base should sit on the platform (simulating the ground) of a shake table. Strings are allowed to attach the base onto the platform. The tower must have an open-air deck on the top to hold the loads (simulated by sandbags or equivalence). The loads may be attached to the deck by using strings. The minimum height of the deck is 50cm.
4) The tower must be constructed in a manner to make it as lightweight as possible for saving the cost of the material. The tower should be aesthetically pleasing.
5) The shake table should have a platform, which is controlled by the supplied motor to simulate the lateral ground displacement when an earthquake occurs. Your team is required to design a mechanism for transmitting the motor rotations to lateral movements of the platform on the shake table. Moreover, the platform should move like a sinusoidal wave with a constant frequency and an amplitude not less than 2.5cm and its peak acceleration should not be smaller than 500cm/s2. Additional components for building the shake table may be supplied subject to the approval of the tutor.
6) You should use the two accelerometer sensors to monitor the lateral vibrations of the tower at the deck and base, respectively. One figure designed by using MATLAB should be created to keep track of and live display the measured accelerometer traces. In addition, you should display the trace of PI1 (see Section 3 for the calculating equation), which evaluates the deformation level of your structure. You should convert the accelerometer signals to the unit of cm/s2 instead of Voltage and need to use appropriate data processing and filtering techniques to process the measured signals.

7) You may use MATLAB and/or LabVIEW to test and validate the design concepts during your design process. However, you must use MATLAB ONLY to create computer programs to implement your final solution.

3. Demonstration

1) Your final design is evaluated by the following two performance indices:

PI₁ = max (|A_deck -A_base|)

where A_deck and A_base (unit: cm/s²) denote the acceleration values at the deck and base of the tower, respectively. PI₁ evaluates the deformation level of your tower.

where m_Load and m_Tower (unit: grams) denote the mass of the load placed at the deck and the total mass of your tower (without loads), respectively. PI2 evaluates the supporting capability with respect to material cost of your tower.

2) The peak acceleration of shake table should not be smaller than 500 cm/s² during demonstration.

3) The testing loads are sandbags (or equivalence) of different weights. Your team should decide the maximum load and peak acceleration of shake table applied to your tower during demonstration.

4) The demonstration should last for at least 20 seconds when the shake table starts to perform a simulated earthquake. The structure should not collapse and the load should not fall off during demonstration. Otherwise, it will be counted as failure.

5) Each team has three attempts to demonstrate their structure performance and the best performance indices will be final.

6) The decision of the tutor will be final in any case.

Questions

1) What kinds of strains can an earthquake put on objects such as buildings?

2) Which building materials and structural designs can handle the strains of an earthquake the best?

3) What are some construction techniques engineers use to avoid damage to a building during an earthquake?

4) Explain what is the resonance of structures.

Attachment:- Earthquake Resistant Structures.rar