In formulation of dynamic stiffness matrix , the first step is to evaluate the roots of the equation to get desired f(x), but what will be sensitivity of thickness or a/h in evaluation of the roots of of governing matrix. In my case when i am using a/h=.1 i am getting the roots in order of the 30,4,2 but as i am reducing the a/h=.01 the roots increase 305 ,4,2 that is making DSM matrix very high