An assumed strain triangular solid shell element with bubble function displacements for analysis of plates and shells

Bubble function displacements are used in conjunction with the assumed strain formulation to construct efficient triangular solid shell elements tailored for shell analysis. Two versions of 36-DOF triangular elements are presented with different bubble function displacements and the corresponding assumed strain fields. In the first version the bubble function displacement is independent of the thickness while in the second version the bubble function varies linearly in the thickness direction. The assumed strain fields are carefully selected to alleviate locking effect. The first version models curved shells with flat triangular elements. The second version is effective in alleviating the membrane locking and thus allows more accurate modelling of curved shells. Various numerical examples demonstrate the validity and effectiveness of the present assumed strain formulation elements with the bubble function displacements. Copyright (C) 2001 John Wiley & Sons, Ltd.