The OpenSees shell element library has been enriched by 2 new entries developed by ASDEA Software: the quadrilateral ASDShellQ4 and triangular ASDShellT3 shell elements. Regarding the plate-bending part, they represent thick (shear-deformable) Reissner-Mindlin plates. As is known, low order elements can exhibit transverse-shear locking in the thin plate limit. To overcome this problem, the MITC4 and MITC3 formulations are used. As for the membrane part, both use special formulations (AGQ6-I for ASDShellQ4 and ANDeS for ASDShellT3) to improve the in-plane bending behavior even with very coarse discretization.