Solve structures subjected to stiffness influences#
Stiffness influences can be investigated in two different ways:
Investigate extremes: look a both cases of \(EI =0\) or \(EA =0\) and \(EI = \infty\) or \(EA = \infty\). This allows you to find the extreme cases of forces and envelopes of internal forces / displacements. All real stiffness values should be within the envelope.
Solve with unknown multiplier factor \(n \cdot EI\) or \(n \cdot EA\). This gives you an expression for forces / displacements and allows you to make an asymptotic graph with respect to \(n\).
This topic is treated in chapter 7 of the book Mechanica, Statisch onbepaalde constructies en bezwijkanalyse (in Dutch) (Hartsuijker and Welleman, 2007).