Analytical Model Data Acquisition & Analysis to Inform Design - - PowerPoint PPT Presentation

Lesson 5: Characterize and Analyze – Analytical Model

Data Acquisition & Analysis to Inform Design Decisions

What have we done? What’s next?

We are concerned about acceleration and displacement.

High displacement  high forces on the building, especially at the base. High acceleration  high forces on the building, and on people and objects inside.

Analyzing Data to Avoid High Peak Accelerations

 Each team has collected data about peak

accelerations for at least two cases.

 Would you report results to the client with

confidence?

How can data be distributed?

 Data can be distributed, or spread out, in many ways

Data are distributed to the right, but skewed to the left Data are distributed to the left, but skewed to the right Data are distributed randomly

10 20 30

Left-Skewed

10 20 30

Right-Skewed

5 10 15 20

Random Distribution

Compare Data Across Systems Standard Deviation

 In many cases, the data tend to be around a central

value and have a “normal distribution" like this:

5 10 15 20 25

Normal Distribution

Analyzing Data to Avoid High Peak Accelerations

 Bell curve = normal distribution of data

1 21 41 61 81 Frequency Sample Values

68% 95% 34% 34% 14% 14% 2% 2%

Are current and proposed buildings safe w.r.t. acceleration?

High displacement  high forces on the building, especially at the base. High acceleration  high forces on the building, and on people and objects inside.

Are current and proposed buildings safe w.r.t. displacement?

High displacement  high forces on the building, especially at the base. High acceleration  high forces on the building, and on people and objects inside.

Before we can design a new building, we must understand resonance.

 See video on my youtube channel

Resonance

 A building with a high center of mass shaking back

and forth is like a tall stick with a mass on the end shaking back and forth.

M

This is a beam anchored only on one end – in this case, the bottom. A structure like this is called a cantilever, with a mass load

• n top.

=

A mathematical model helps consolidate contributing factors

𝑔 ∝ 𝑙 𝐼3𝑁

Does this really happen?

Discussion

 What are some advantages and disadvantages

• f using models to evaluate designs?

What’s Next?

Individual Assessments

 Assessment 5: Standard Deviation  Assessment 6: Resonance