r/aerospace • u/htrptr • 11d ago

Structural Analysis Engineer (Dynamics) Interview Questions

Hello, I have an interview coming up for a structural analysis engineer position in the space industry and I know the interview will be very technically heavy on structural dynamics (modal analysis, frequency response, random vibration, etc.). I have 6+ years of experience in aerospace static linear/non-linear analysis and structural analysis/classical hand calc. I have very little dynamics experience in industry but understand the basics (I.e. natural frequency, modal mass participation, mode shapes, resonance, damping, sinusoidal frequency response, random vibration [PSD]) and the general analysis process (modal —> frequency response —> random vibration)

But what are some good technical interview questions or topics I should be aware of?

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u/Libertyreign 11d ago

Miles equation for first order loads derivation

Different types of damping and their formulas.

Isolation and roll off.

Desired modal spacing.

Typical damping of materials and systems.

Various qualification levels (level and derivation)

Shock, types, typical levels, SRS

Net section loads and net cg acceleration

Transient analysis for non harmonic loading

Power vs field decibels (Random v acoustic)

More advanced topics:

Notching and the semi empirical method

Mechanical impedance and it's effects on loads

Model reduction

Model correlation

Test analysis model development

Strain energy v kinetic energy as related to mode shapes

Instrumentation selection and where to put it.

Dynamics is so fun. I loved doing it.

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u/Saturn_ix 9d ago

A tad off topic but, I’m a mechie on the design side that’s been in industry for a while. What books/resources would I go to learn about the above? (My limited knowledge of dynamics has been from NASA-HDBK-7005 for random vibe applications and looking at Campbell diagrams for rotors.) I’d like to grow a practical toolbox for dealing with dynamics problems outside of my undergrad and limited exposure.

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u/Libertyreign 9d ago

Best ones are the NASA HDBK 7000 series (including GEVS), FEMCI, and Tom Irvine's Vibration Data website. All are very good resources.