清华大学有限元分析课件2-5 Finite Element Programming_279403862.pdf

第2 章 直接刚度法 2.5 有限元程序设计 Finite Element Programming [Bathe]: Chapter 12 [Zhang]: Chapter 2 Finite Element Method 有限元程序实现 Nodal point information l  Nodal point information Identification (destination) array: ID(NDF,NUMNP) ID(i, A) = 0 — The ith DOF at the nodal point A is defined in the global system ID(i, A) = 1 — The DOF is not defined θ !! NDF － Degrees of freedom per node ## !! %% Ø  Membrane element — 2 ## Ø  Plate element — 3 Ø  Shell element — 5 θ !! $$ Coordinate arrays !! %% !! ## X = [x1, x2, …, xn] $$ !! !! Y = [y1, y2, …, yn] θ!! !! Z = [z1, z2, …, zn] The relationship between global node numbers and global equation numbers as well as nodal boundary condition information: ⎧ P if A ∈η −η P － Global equation number ID(i,A) = ⎨ 0 if A ∈η u η － The set of global node numbers ⎩ u ηu － The set of nodes at which uh = u i — DOF number 1≤ i ≤ NDF A — Global node number 2/26 School of Aerospace, Tsinghua University Finite Element Method 有限元程序实现 Nodal point information (3)