A spherical shell is subjected to outward point loads on the x-axis and inward point loads on the z-axis.

*CONTROL_SHELL Hemispherical Load LS-DYNA Manual Section: *CONTROL_SHELL Example: Hemispherical Load Filename: control_shell.hemi-load.k Description: A spherical shell is subjected to outward point loads on the x-axis and inward point loads on the z-axis. Model: The 1/8 symmetry model of a sphere measures 10 inches in radius with a thickness of 0.04 inches. The model contains 48 shell elements. A force of one pound is applied in the positive x-direction to the node on the x-axis. A force of one pound is applied in the negative z-direction to the node on the y-axis. Input: The element formulation is the Hughes-Liu shell with four integration points through the thickness. Note: If B-T element formulation is used the solution would be incorrect. To fix it, the Belytschko-Tsay shell requires the Belytschko-Wang-Chiang warpage stiffness modification (*CONTROL_SHELL). The concentrated loads are applied to two nodes (*DEFINE_CURVE, *LOAD_NODE_POINT). Results: The oscillation of the node on the z-axis shows a regular oscillatory behavior. Since there is no specified damping, oscillations would be expected. Reference: Belytschko, T., Wang and Chiang.

*CONTROL_ENERGY *CONTROL_HOURGLASS *CONTROL_SHELL *CONTROL_TERMINATION *DATABASE_BINARY_D3PLOT *DEFINE_CURVE *ELEMENT_SHELL *END *KEYWORD *LOAD_NODE_POINT *MAT_PLASTIC_KINEMATIC *NODE *PART *SECTION_SHELL *TITLE

*KEYWORD *TITLE Hemispherical Shell $ $ LSTC Example $ $ Last Modified: September 12, 1997 $ $ Units: lbf-s2/in, in, s, lbf, psi, lbf-in $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $$$$ Control Output $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8 $ *CONTROL_TERMINATION $ endtim endcyc dtmin endneg endmas 6.000E-02 $ *CONTROL_ENERGY $ hgen rwen slnten rylen 2 2 $ *CONTROL_HOURGLASS $ ihq qh 4 $ *CONTROL_SHELL $ wrpang itrist irnxx istupd theory bwc miter -2 1 $ $ *DATABASE_BINARY_D3PLOT $ dt lcdt 6.000E-04 $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $$$$ Loading $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $$$$ Load node 1 in the positive x-direction. $ *LOAD_NODE_POINT $ nid dof lcid sf cid m1 m2 m3 1 3 1 1.0 $ $$$$ Load node 46 in the negative z-direction. $ *LOAD_NODE_POINT $ nid dof lcid sf cid m1 m2 m3 46 1 1 -1.0 $ $ *DEFINE_CURVE $ lcid sidr scla sclo offa offo 1 $ abscissa ordinate 0.000E+00 1.000E+00 1.000E+00 1.000E+00 $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $$$$ Define Parts and Materials $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $...>....1....>....2....>....3....>....4....>....5....>....6....>....7....>....8 $ *PART $ pid sid mid eosid hgid adpopt Hemisphere 1 1 1 $ $ *MAT_PLASTIC_KINEMATIC $ mid ro e pr sigy etan beta 1 1.000E-03 6.825E+07 0.3 600000.00 0.000E+00 0.000E+00 $ src srp fs 0.000E+00 0.000E+00 0.000E+00 $ $ *SECTION_SHELL $ sid elform shrf nip propt qr/irid icomp 1 5 $ t1 t2 t3 t4 nloc 4.000E-02 4.000E-02 4.000E-02 4.000E-02 $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $$$$ Define Nodes and Elements $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $$$$ Multiple nodes have boundary conditions to simulate symmetry. $ $ *END