When analyzing trusses, one can compute the natural frequencies of the truss, using matrix methods, i.c. solve the eigenvalue problem associated with the construction. One needs to assemble the ******mass matrix****** for that. This mass matrix is singular and can therefor not be inverted. What does it physically mean, that the mass matrix is singular ?

(The corresponding stiffness matrix is also singular, meaning the truss cannot deform, without being supported in some manner.).

Would the singularuity of the mass matrix mean, that the truss cannot

******vibrate

******without being supported ?