*HEADING CONN_XPL_FREE_AXI: free vibration of spring-mass-dashpot [CONN2D2] Damped free vibration: u(t) = e^{-w_n*t} u_0 ( xi/sqrt(1-xi*xi) sin(w_d*t) + cos(w_d*t) ) u(0) = u_0 = 1.0, v(0) = 0.0 w_n = sqrt(k/m) = 2.0 xi = c/(2 m w_n) = 5/48 w_d = w_n sqrt(1 - xi*xi) = 1.98912 ************************************************* ** create a rigid base for the connector elements ************************************************* *NODE,NSET=PLATE 101, 0., 0. 107, 0., 6. 701, 6., 0. 707, 6., 6. *NGEN,NSET=E1 101,107,1 *NGEN,NSET=E2 107,707,100 *NGEN,NSET=E3 701,707,1 *NGEN,NSET=E4 101,701,100 *NGEN,NSET=INTERIOR 201,207,1 301,307,1 401,407,1 501,507,1 601,607,1 *NSET, NSET=NPLATE E1, E2, E3, E4, INTERIOR *ELEMENT,TYPE=CAX4R,ELSET=PLATE 101, 101,201,202,102 *ELGEN,ELSET=PLATE 101,6,1,1,6,100,100 *SOLID SECTION,ELSET=PLATE,MATERIAL=MAT *MATERIAL,NAME=MAT *ELASTIC 1.0,0.0 *DENSITY 1.0, *NODE,NSET=REF 1000, 0.,0. *RIGID BODY, REFNODE=1000, ELSET=PLATE, TIE=NPLATE ************************************************* *NODE,NSET=TOP 1303, 2., 2. 1305, 2., 4. 1307, 2., 6. 1503, 4., 2. 1703, 6., 2. 1705, 6., 4. ******************************************* ** put mass and rotary inertia at top nodes ******************************************* *ELEMENT, TYPE=MASS, ELSET=MASS 1011,1303 1012,1305 1013,1307 1021,1503 1031,1703 1032,1705 *MASS, ELSET=MASS 12.0 *ELEMENT, TYPE=ROTARYI, ELSET=ROTI 2011,1303 2012,1305 2013,1307 2021,1503 2031,1703 2032,1705 *ROTARY INERTIA, ELSET=ROTI 120.0, 120.0, 120.0 ******************************** ** define the connector elements ******************************** *ELEMENT, TYPE=CONN2D2, ELSET=AX 11, 202, 1303 *ELEMENT, TYPE=CONN2D2, ELSET=CAR 12, 204, 1305 *ELEMENT, TYPE=CONN2D2, ELSET=SLT 13, 206, 1307 *ELEMENT, TYPE=CONN2D2, ELSET=ROT 21, 402, 1503 *ELEMENT, TYPE=CONN2D2, ELSET=CAR-ROT 31, 602, 1703 *ELEMENT, TYPE=CONN2D2, ELSET=SLT-ALN 32, 604, 1705 *ELSET,ELSET=CONNALL AX, CAR, SLT, ROT, CAR-ROT, SLT-ALN *ORIENTATION, NAME=LDIRECTION ** orientation along node line 1.,1.,0., -1.,1.,0. ***** *CONNECTOR SECTION, ELSET=AX, BEHAVIOR=CB_AX AXIAL, *CONNECTOR BEHAVIOR, NAME=CB_AX *CONNECTOR ELASTICITY, COMPONENT=1 48.0, *CONNECTOR DAMPING, COMPONENT=1 5.0, *CONNECTOR CONSTITUTIVE REFERENCE 1.31421356, ***** *CONNECTOR SECTION, ELSET=CAR, BEHAVIOR=CB_CAR CARTESIAN, LDIRECTION, *CONNECTOR BEHAVIOR, NAME=CB_CAR *CONNECTOR ELASTICITY, COMPONENT=1 48.0, *CONNECTOR DAMPING, COMPONENT=1 5.0, *CONNECTOR ELASTICITY, COMPONENT=2 48.0, *CONNECTOR DAMPING, COMPONENT=2 5.0, *CONNECTOR CONSTITUTIVE REFERENCE 1.31421356,-0.1 ***** *CONNECTOR SECTION, ELSET=SLT, BEHAVIOR=CB_SLT SLOT, LDIRECTION, *CONNECTOR BEHAVIOR, NAME=CB_SLT *CONNECTOR ELASTICITY, COMPONENT=1 48.0, *CONNECTOR DAMPING, COMPONENT=1 5.0, *CONNECTOR CONSTITUTIVE REFERENCE 1.31421356, ***** *CONNECTOR SECTION, ELSET=ROT, BEHAVIOR=CB_ROT ROTATION, LDIRECTION, *CONNECTOR BEHAVIOR, NAME=CB_ROT *CONNECTOR ELASTICITY, COMPONENT=6 480.0, *CONNECTOR DAMPING, COMPONENT=6 50.0, *CONNECTOR CONSTITUTIVE REFERENCE , , , , , -5.72957795 ***** *CONNECTOR SECTION, ELSET=CAR-ROT, BEHAVIOR=CB_CAR-ROT CARTESIAN,ROTATION LDIRECTION, *CONNECTOR BEHAVIOR, NAME=CB_CAR-ROT *CONNECTOR ELASTICITY, COMPONENT=1 48.0, *CONNECTOR DAMPING, COMPONENT=1 5.0, *CONNECTOR ELASTICITY, COMPONENT=2 48.0, *CONNECTOR DAMPING, COMPONENT=2 5.0, *CONNECTOR ELASTICITY, COMPONENT=6 480.0, *CONNECTOR DAMPING, COMPONENT=6 50.0, *CONNECTOR CONSTITUTIVE REFERENCE 1.31421356,-0.1, , , ,-5.72957795 ***** *CONNECTOR SECTION, ELSET=SLT-ALN, BEHAVIOR=CB_SLT SLOT,ALIGN LDIRECTION, ***** *BOUNDARY REF, 1,2 REF, 6,6 ************************************ *ELSET,ELSET=QA_TEST_CONNALL CONNALL, ** *STEP, NLGEOM=YES Damped free vibration. *DYNAMIC, EXPLICIT, DIRECT 0.075, 8.0 *FILE OUTPUT, NUM=4 *EL FILE, ELSET=CONNALL CP,CU, *OUTPUT,HISTORY, FREQ=1 *ELEMENT OUTPUT, ELSET=CONNALL CP,CU,CCU,CV *NODE OUTPUT, NSET=TOP U,V,A *OUTPUT,HISTORY,VARIABLE=PRESELECT,TIMEINT=2 ***OUTPUT,HISTORY,VARIABLE=PRESELECT *END STEP