# SD2170 Energy Methods 6.0 credits

The course covers the theoretical background and some practical experience on vibro-acoustic predictions based on statistical energy analysis (SEA). This approximate method is based upon a potential flow model and is quickly applied for complex built-up structures as buildings and vehicles. It provides an alternative view point that is useful for post processing and understanding measurement data and results from advanced numerical dynamic predictions of high frequency response.

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Headings with content from the Course syllabus SD2170 (Spring 2022–) are denoted with an asterisk ( )

## Content and learning outcomes

### Course contents

Introduction to the “high-frequency” response of engineering structures. Free vibrational energy as a response variable. Statistical estimates of the maximum and mean response. Fuzzy structure attachments. The potential flow model and its failure for strong coupling and non-resonant motion. Asymptotic methods for modal density and vibration conductivity. SEA formulations for basic structures. The approximate solution to some “impossible” problems including: acoustic fatigue of space rockets, damage to colliding houses, vibro-acoustic transmission in multi-storey buildings and ships. Introduction to current areas of research and to complementary formulations such as the Wave Intensity Method, the Smooth Energy Method, the Power Injection Method, Transient SEA, the exact power balance formulation, hybrid SEA-FEM formulations. Introduction to commercial software and a computer exercise.

### Intended learning outcomes

Students graduating from the course shall be able to:

• explain and communicate the implications of uncertainty and complexity on the predictability of vibro-acoustic response.
• formulate the law of vibrational energy conservation in SEA form for some common structural and acoustic systems.
• explain and communicate the capability of the potential flow model for energy.
• explain and communicate the limitations of the potential flow model.
• take a decision on whether to use a commercial software for a particular problem

### Course disposition

No information inserted

## Literature and preparations

### Specific prerequisites

Basic courses in mathematics, mechanics.

### Recommended prerequisites

No information inserted

### Equipment

No information inserted

### Literature

No information inserted

## Examination and completion

If the course is discontinued, students may request to be examined during the following two academic years.

A, B, C, D, E, FX, F

### Examination

• TEN1 - Examination, 6.0 credits, grading scale: A, B, C, D, E, FX, F

Based on recommendation from KTH’s coordinator for disabilities, the examiner will decide how to adapt an examination for students with documented disability.

The examiner may apply another examination format when re-examining individual students.

### Other requirements for final grade

Examination (TEN1; 6 university credits).

### Opportunity to complete the requirements via supplementary examination

No information inserted

### Opportunity to raise an approved grade via renewed examination

No information inserted

### Ethical approach

• All members of a group are responsible for the group's work.
• In any assessment, every student shall honestly disclose any help received and sources used.
• In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.

## Further information

### Course web

Further information about the course can be found on the Course web at the link below. Information on the Course web will later be moved to this site.

Course web SD2170

### Offered by

SCI/Aeronautical and Vehicle Engineering

### Main field of study

No information inserted

Second cycle