Variational setting for cracked beams and shallow arches
We develop a rigorous mathematical framework for the weak formulation of cracked beams and shallow arches problems. First, we discuss the crack modeling by means of massless rotational springs. Then we introduce Hilbert spaces, which are sufficiently wide to accommodate such representations. Our main result is the introduction of a specially designed linear operator that "absorbs" the boundary conditions at the cracks. We also provide mathematical justification and derivation of the Modified Shifrin's method for an efficient computation of the eigenvalues and the eigenfunctions for cracked beams.