A comparative formulation of T3γ_s, DST, DKMT and MITC3+ triangular plate elements with new numerical results based on s-norm tests

The paper deals with plate bending triangular elements with shear effect included, having only three degrees of freedom at each corner node. In that category, we select four elements due to their appreciation in the academic world and performances for practical applications using industrial software. Those four elements are T3γ_s (1982) (equivalent to MITC3 (2004)), DST (1989), DKMT (1993), and MITC3+ (2014). The present paper focuses on the detailed formulation of those elements using the same notation and with emphasis on their theoretical difference. In particular, the paper shows that for very thick plates DKMT, and MITC3 are equivalent. The main other contribution deals with a detailed analysis of the numerical results for classical tests or dealing with convergence performance evaluation using s-norm tests for the whole range of extremely thick to thin plates. The best elements emerging from the present study are DKMT and MITC3+ with a slight advantage to the first due to its simplicity in formulation and performance in all tests.