++++ ++++ ++++ ++++ ++++ Concept Question ++++ ++++ ++++ ++++ ++++ What do you think the eigenvectors of the element sti?- ness matrix represent? 1. a basis in which the sti?ness matrix would be diago- nal (if rotated to that basis) 2. a set of nodal displacements for the element corre- sponding to the physical deformation modes of the element (rigid translations and rotation, pure shear, pure stretching, combined shear, combined stretch- ing, pure dilatation/compression, etc.) 3. nothing in particular, it’s just a mathematical con- cept dissociated from any physical interpretation. 1. ++++ Statement (1) 2. ++++ Statement (2) 3. ++++ Statement (1) and (2) 4. ++++ Statement (3) 5. ++++ DKDU The correct answer is ++++