I am 5th year PhD, about to submit my thesis in few months and defend in around September this year. My computational materials science PhD thesis involved using a commercial software (ABAQUS) to model a machining problem. I had to come up with material models and write python codes to build new geometries and stuff. I did decent in my PhD with 3 publications in decent journals and few in preparation.
Now, I learnt the theory behind the working of the commercial software while beginning my work. I did it entirely through self study. However, my PhD thesis did not involve any manipulation or working with the actual theoretical formulation of the software. So, I don't have any working experience with the formulation of (Finite element method) FEA form of a problem and implementing it.
Now, all the jobs or postdoc positions in FEA application requires one to be able to solve a problem by hand, compare with analytical solutions, be proficient in implementing FEA weak forms into the commercial software...and so on. I don't know if I would be able to do it when required as I have not worked with it till now.
I don't know if I am even eligible to call myself a PhD as I feel unconfident/ashamed in my abilities to be called an expert in the numerical analysis field. What do I do?