New publication on differentiated vibration and stress solver

Our new publication focuses on the derivation of an adjoint structural stress and vibration solver using algorithmic differentiation. Both derivations utilize a combination of symbolic and algorithmic differentiation techniques and enable gradient calculations at a cost independent on the number of inputs.

TL;DR:

• Gradients of the maximum von Mises stress with respect to all mesh nodes can be obtained at an additional cost of just one linear system solve.

• Gradients of the eigenvalues with respect to all mesh nodes can be obtained at an additional cost of just one outer product per eigenvalue.

• Child classes of the differentiated parent classes automatically allow gradient calculations with no additional code differentiation required - e.g., extending the code from isotropic to composite materials.

Coupled with a differentiated CAD kernel, this can be used to perform computationally cheap CAD-based multidisciplinary optimizations.