Some notes on the early history of hybrid stress finite element method

The first remark of this paper is to disclose a historical fact that the assumed stress hybrid finite element method pioneered by Plan [1] in 1964 was actually developed originally based on the Hellinger-Reissner principle and not on the complementary energy principle as indicated, in the published paper. The other remark is that Dick Gallagher was the first person to prove the fact that the rectangular plane stress elements by Plan is identical to the Turner element presented in 1956. Finally, through a formulation by Hellinger-Reissner principle a formal proof is given of the fact that the Plan element is also identical to Wilson's incompatible element. Copyright (C) 2000 John Wiley & Sons, Ltd.