H.A. Mang, R.H. Gallagher:
""Potential Energy with Iterative Correction" ... or Deterioration, that is the Question";
International Journal for Numerical Methods in Engineering, 12 (1978), 1461 - 1472.
The wriers, in Reference 2, have assessed two markedly different methods proposed for the improvement of finite element solutions to preoblems requiring C^1 interelement continuity (for example, plate bending problems) in which basis functions yielding only C^0 interelement continuity are employed. One of these two methods, the so-called Simpliefied Hybrid Displacement Method (SHDM), was shown to be unsatisfactory in this regard. Crisfield, in a discussion of Reference 2, has primarily called attention to another concept, termed Potential Energy with Iterative Correction (PEIC), given by him in Reference 3, intended to achieve the same goal. Also, criticism was raised concerning the numerical examples employed by the writers.
The purpose of this reply is to:
1. Clarify theoretical misconceptions concerning the PEIC method;
2. Present numerical evidence that the alleged 'iterative correction' may turn out to be an 'iterative deterioration'; and
3. Refute criticism raised regarding Reference 2.