Sensitivity of Discrete Systems

The first step in the analysis of a complex structure is typically a spatial discretization of the continuum equations into a finite element, finite difference or a similar model. The analysis problem then requires the solution of algebraic equations (static response), algebraic eigenvalue problems (buckling or vibration) or ordinary differential equations (transient response). The sensitivity calculation is then equivalent to the mathematical problem of obtaining the derivatives of the solutions of those equations with respect to their coefficients. This is the main subject of the present chapter.