A recruiter contacted me after I replied to his post on LinkedIn and sent him my resume. He set up a phone interview for a few days later with two senior FEA engineers.

First, he asked me to go over my resume, and then he started asking technical FEA & Strength of Materials questions for the entire 30 minutes. There were no behavioral questions or anything else.

I believe asking such questions in a phone interview doesn't make sense. They should at least ask you some questions about yourself.

If you want to apply to Apple, you should study material from mechanical engineering books as if you were preparing for a comprehensive PhD exam.

The recruiter emailed me 10 minutes after I hung up the phone and told me it was a "no-go."

When modeling rubber-like material in explicit FEA, you cannot set Poisson's ratio to 0.5. Why? What would happen in the solver if you do that?

I noted that it leads to an infinity in the stiffness matrix, but he wanted more details.

Consider a cantilever beam with a load at the free end. Now tell me if there are any shear forces in the beam. Explain how the shear stresses distribute on the cross-section of the beam, as well as the top and bottom layers. Where does the maximum shear stress occur?

He tried to add more challenge by asking different things; we spent about 15 minutes on this.