/* * ====================================================================== * Finite element model of shear-beam using 4 node shell finite element. * * In this example, the cantilever beam is modeled with a 8x2 irregularly * shaped finite element mesh. * * Written By : Lanheng Jin April, 1994 * ====================================================================== */ print "*** DEFINE PROBLEM SPECIFIC PARAMETERS \n\n"; NDimension = 3; NDofPerNode = 6; MaxNodesPerElement = 4; /* * =============== * Define the Mesh * =============== */ StartMesh(); print "*** GENERATE GRID OF GEOMETRY FOR FE MODEL \n\n"; L = 48 in; /* Length */ b = 12 in; /* Width */ t = 1 in; /* Thickness */ print "*** GENERATE GRID OF NODES FOR FE MODEL \n\n"; y = 0 in; AddNode( 1, [ 0.0 in, y, 6.0 in]); AddNode( 2, [ 0.0 in, y, 0.0 in]); AddNode( 3, [ 0.0 in, y,-6.0 in]); AddNode( 4, [ 6.0 in, y, 6.0 in]); AddNode( 5, [ 7.0 in, y, 0.0 in]); AddNode( 6, [ 8.0 in, y,-6.0 in]); AddNode( 7, [12.0 in, y, 6.0 in]); AddNode( 8, [14.0 in, y, 0.0 in]); AddNode( 9, [16.0 in, y,-6.0 in]); AddNode(10, [18.0 in, y, 6.0 in]); AddNode(11, [18.0 in, y, 0.0 in]); AddNode(12, [18.0 in, y,-6.0 in]); AddNode(13, [24.0 in, y, 6.0 in]); AddNode(14, [22.0 in, y, 0.0 in]); AddNode(15, [20.0 in, y,-6.0 in]); AddNode(16, [30.0 in, y, 6.0 in]); AddNode(17, [27.0 in, y, 0.0 in]); AddNode(18, [24.0 in, y,-6.0 in]); AddNode(19, [36.0 in, y, 6.0 in]); AddNode(20, [32.0 in, y, 0.0 in]); AddNode(21, [28.0 in, y,-6.0 in]); AddNode(22, [42.0 in, y, 6.0 in]); AddNode(23, [40.0 in, y, 0.0 in]); AddNode(24, [38.0 in, y,-6.0 in]); AddNode(25, [48.0 in, y, 6.0 in]); AddNode(26, [48.0 in, y, 0.0 in]); AddNode(27, [48.0 in, y,-6.0 in]); print "*** ATTACH ELEMENTS TO GRID OF NODES \n\n"; nn = 9; for(j=1; j < nn; j=j+1) { for(i=1; i<=2; i=i+1) { elmtno = i+2*(j-1); a = 3*(j-1)+i+1; b = 3*j+i+1; c = 3*j+i; d = 3*(j-1)+i; node_connec = [a, b, c, d]; AddElmt(elmtno, node_connec, "name_of_elmt_attr"); } } /* * =============================================== * Define Element, Section and Material Properties * =============================================== */ print "*** DEFINE ELEMENT, SECTION AND MATERIAL PROPERTIES \n\n"; ElementAttr("name_of_elmt_attr") { type = "SHELL_4NQ"; section = "mysection"; material = "ELASTIC"; } MaterialAttr("ELASTIC") { poisson = 0.25; E = 30000 ksi; } SectionAttr("mysection") { thickness = 1 in; } /* * ========================= * Setup Boundary Conditions * ========================= */ print "*** SET UP BOUNDARY CONDITIONS \n\n"; /* Establish array for full fixity condition */ u_id = 1; v_id = 1; w_id = 1; rx_id = 1; ry_id = 1; rz_id = 1; bc_fc = [u_id,v_id,w_id,rx_id,ry_id,rz_id]; /* Apply full fixity to corner nodes */ for (i=1; i<=3; i=i+1) { FixNode(i, bc_fc); } /* * ================== * Add external loads * ================== */ print "*** APPLY EXTERNAL LOADS \n\n"; Fx = 0 lbf; Fy = 0 lbf; Fz = 10000 lbf; Mx = 0 lbf*in; My = 0 lbf*in; Mz = 0 lbf*in; NodeLoad( 25, [Fx, Fy, Fz, Mx, My, Mz]); NodeLoad( 27, [Fx, Fy, Fz, Mx, My, Mz]); Fx = 0 lbf; Fy = 0 lbf; Fz = 20000 lbf; Mx = 0 lbf*in; My = 0 lbf*in; Mz = 0 lbf*in; NodeLoad( 26, [Fx, Fy, Fz, Mx, My, Mz]); /* * ===================================== * Compile and Print Finite Element Mesh * ===================================== */ EndMesh(); PrintMesh(); /* * ========================== * Compute Stiffness Matrices * ========================== */ print "\n*** COMPUTE STIFFNESS MATRICES \n\n"; SetUnitsType("US"); stiff = Stiff(); eload = ExternalLoad(); lu = Decompose(Copy(stiff)); displ = Substitution(lu, eload); /* * ================================ * Print displacements and stresses * ================================ */ PrintDispl(displ); PrintStress(displ); quit;