[NODE/ELEMENT]     While defining the wall element, when to consider the sub type option as plate and when as membrane?

A: Wall element (membrane type) is generally used to model shear walls being subjected to in-plane loads only. Whereas, Wall element (plate type) is suitable for modeling common walls intended to resist in-plane loads as well as out-of-plane bending moments.


Two types of wall elements included in MIDAS/Gen are:


Wall element type 1 (Membrane type): in-plane stiffness + rotational stiffness about the vertical direction.
Shear walls are generally modeled with 4-node plane stress elements, which best reflect
the characteristics of shear walls. This type of element does not have rotational stiffness about the axis perpendicular to the plane of the element at the connecting nodes.


When flexural beams are connected to the wall element’s nodes, incompatibility in degrees of freedom results. Moreover, additional transformation process is required for design because all element forces are produced in terms of nodal forces or stresses rather than wall member forces and moments.
Wall element type 2 (Plate type): in-plane stiffness + rotational stiffness about the vertical direction + out-of-plane bending stiffness
To overcome, above said limitation, the Wall element type 2 (Plate type) is introduced in midas Gen. This allows you to select out-of-plane bending stiffness to be included in the analysis