To grasp nonlinear structural analysis, unlearn Hooke’s Law, .
And all derivative outcomes of Hooke’s Law. Like and .
When steel yields, concrete cracks, etc., Hooke’s Law no longer applies and holding on to it can lead to erroneous interpretations of nonlinear structural response.
But don’t let Hooke’s Law go completely. In addition to performing linear analysis, linear-elastic materials are useful for diagnosing problems in your nonlinear models.