验证例题22.pdf

1Example 22 Title Simply supported cylindrical shell Description Compute the axial deformations and vertical displacements of a shell structure under its self weight.Only a quarter model may be analyzed due to symmetry.2 Structural geometry and analysis model Example 60 3MODEL Analysis Type 3-D static analysis Unit System ft,lbf Dimension Length 25 ft Radius 25 ft Central angle 40 Element Plate element (Thick type)Material Modulus of elasticity E =4.32 108 lbf/ft2 Weight density =360 lbf/ft3 Element Property Element size a b=25/6 ft 40 (/180)25/6 ft Thickness t =0.25 ft Boundary Condition Nodes 1 7 ;Constrain Dx,Dz and Ry.(Simple supports)Nodes 1 43 ;Constrain Dx,Ry and Rz.(Symmetric about Y-Z plane)(at an increment of 7)Nodes 43 49 ;Constrain Dy,Rx and Rz.(Symmetric about X-Z plane at Y=25 ft)Load Case Self weight is imposed in the-Z direction.4Results Axial displacements of the structure Vertical displacements of the structure Example 60 5 Displacements 6Comparison of Results Unit:ft Axial deformation(Y)Vertical displacement(Z)Node Theoretical SAP2000MIDAS/Gen NodeTheoreticalSAP2000 MIDAS/Gen 1 0.0004 0.0 0.0 43 0.045 0.046 0.046 2 0.0009 0.0005 0.0005 44 0.027 0.031 0.031 3 0.0020 0.0018 0.0018 45-0.018-0.013-0.013 4 0.0030 0.0029 0.0029 46-0.082-0.078-0.078 5 0.0021 0.0024 0.0024 47-0.155-0.155-0.155 6-0.0016-0.0017-0.001748-0.241-0.234-0.234 7-0.0120-0.0118-0.011849-0.309-0.307-0.307 References MacNeal,R.H.and Harder,R.L.,“A Proposed Standard Set of Problems to Test Finite Element Accuracy”,Finite Elements in Analysis and Design 1,1985,pp.3-20,North-Holland.Zienkiewicz,O.C.,“The Finite Element Method”,McGraw-Hill,1977.Scordelis,A.C.,and Lo,K.S.,“Computer Analysis of Cylindrical Shells”,Journal of the American Concrete Institute,Vol.61,May 1964.