 Bilinear quadrilateral element

A bilinear quadrilateral element is a type of finite element used in numerical methods for solving partial differential equations (PDEs) in two dimensions. It is particularly popular in the finite element method (FEM) for structural and fluid problems. The key characteristics of bilinear quadrilateral elements include: ### Shape and Nodes - **Geometry**: A bilinear quadrilateral element is defined in a rectangular (quadrilateral) shape, typically with four corners (nodes).