CFVR4702 - CALTRANS: Seismic Analysis Y-axis
Seismic Analysis on a 1 DOF beam according to CALTRANS. (soil profile type C)
This example compares spectrum accelerations given by CivilFEM to accelerations obtained when solving on a 1 DOF beam and to the correct CALTRANS spectum accelerations.
The model is 1 element beam with only 1 DOF, which direction the CivilFEM spectrum is set (the rest of the DOF are constrained). A different mass is applied at the free end of the beam for the beam period to be equal to the 20 CivilFEM spectrum points. After solving, the mass acceleration is obtained and compared to the CivilFEM spectrum acceleration and to the correct value. Therefore, this example checks the following results:
- CivilFEM spectrum is defined correctly by comparing to the correct value
- CivilFEM spectrum is applied correctly and response acceleration is equal to spectrum acceleration
Element types used in the model: BEAM4, MASS21 Needed CivilFEM Modules: |
|
| Model Statistics | |
| Number of elements | 1 |
| Number of nodes | 2 |
| Number of civil materials | 1 |
| Number of cross sections | 1 |
| Number of shell vertices | 0 |
Log file: CFVR4702.DAT
FINISH ~CFCLEAR,,1 NomFile='CFVR4702' /TITLE, %NomFile%, CALTRANS: Seismic Analysis Y-axis ! ---------------------------------------------------------------------- ! Model definition ! ---------------------------------------------------------------------- ! CivilFEM Setup: Code & Units ~UNITS,,LENG,CM ~UNITS,,TIME,S ~UNITS,,FORC,KP ~CODESEL,,,,,CALTRANS /PREP7 ! Preprocessor ! ---------------------------------------------------------------------- ! Materials: A-42 ~CFMP,1,LIB,STEEL,EA,A42 ! Modify density (Rho = 0) ~CFMP,1,USER ~CFMP,1,DatGen,RHO,,0 ! Element Types ET,1,BEAM4 ! Type 1: 3D Beam ET,2,MASS21 ! Type 2: Mass ! Sections ~SSECLIB,1,1,1,1 !IPE 80 ~BMSHPRO,1,BEAM,1,1,,,4,,0,, ! Nodes L = 10 ! L : Bar length N, 1 N,10,L ! Elements TYPE,1 MAT ,1 REAL,1 EN,1,1,10 EPLOT ! Parameters *GET,AR20,EX,1 ! Ex : Elastic Modulus ~CFGET,AR22,SECTION,1,MECHPROP,A,,2 ! Area : Bar area ~CFGET,AR23,SECTION,1,MECHPROP,IZZ,,2 ! Izz : Moment of inertia ~CFGET,AR24,SECTION,1,MECHPROP,IYY,,2 ! Iyy : Moment of inertia ! Seismic Spectrum ~DEFSPEC,ALL,0.4,C2,0,5,1 pi = 3.141592654 ! ---------------------------------------------------------------------- ! DATA CHECK ! ---------------------------------------------------------------------- ! Data comparision number NComp = 40 NComp_ch = 0 ! Marix dim. *DIM,LABEL,CHAR,Ncomp,1 *DIM,LABEL_CH,CHAR,Ncomp_ch,1 *DIM,VALUE,,Ncomp,3 *DIM,VALUE_CH,CHAR,Ncomp_ch,3 *DIM,TOLER,,Ncomp,2 *DO,ARG1,1,20 /PREP7 ~CFGET,AR26,SEISM,,SPEC,TH,,ARG1,1 ! Period ! Labels LABEL(ARG1,1) = 'Sa(%ARG1%)y' LABEL(20+ARG1,1) = 'Sa(%ARG1%)y' AR25=12*AR20*AR23/L**3 ! Bending rigidity around Z axis AR27=AR25*(AR26/(2*pi))**2 ! Mass applied at end R,2,0,AR27 TYPE,2 MAT, 1 REAL,2 EN,2,10 FINISH /SOLU ! Solution ! --------------------------------------------------------------------- ! Displacements D,1,,,,,,ALL D,10,,,,,UX, ,UZ,ROTX,ROTY,ROTZ ~MODLSOL,1 ~CMBMOD,NONE,HORIZONT,NONE,0,0.0001 ! Query results *GET,ARG5,NODE,10,U,Y ! Correct values VALUE(20-ARG1+1,1)=ARG5*AR25/AR27 ! Acceleration ! Obtained values ~CFGET,VALUE(20-ARG1+1,2),SEISM,,SPEC,SDH,,ARG1,1 ! Y components of linear spectrum ~CFGET,VALUE(40-ARG1+1,2),SEISM,,SPEC,SDH,,ARG1,1 ! Y components of linear spectrum ! CivilFEM gives the spectrum Normalized by gravity. ! To compare it must be changed to acceleration user units. VALUE(20-ARG1+1,2) = VALUE(20-ARG1+1,2)*981 VALUE(40-ARG1+1,2) = VALUE(40-ARG1+1,2)*981 /PREP7 EDELE,2 *ENDDO ! Correct values ! ---------------------------------------------------------------------- VALUE(40,1) = 72.2997 VALUE(39,1) = 117.391148 VALUE(38,1) = 224.932138 VALUE(37,1) = 340.8957208 VALUE(36,1) = 579.7626109 VALUE(35,1) = 731.358104 VALUE(34,1) = 913.8442046 VALUE(33,1) = 974.8560214 VALUE(32,1) = 1013.420957 VALUE(31,1) = 1011.491627 VALUE(30,1) = 990.7245267 VALUE(29,1) = 955.8950007 VALUE(28,1) = 897.1263346 VALUE(27,1) = 753.1427176 VALUE(26,1) = 666.5882813 VALUE(25,1) = 539.4402497 VALUE(24,1) = 392.5962 VALUE(23,1) = 392.5962 VALUE(22,1) = 392.5962 VALUE(21,1) = 392.5962 ! Warning and error tolerances ! ---------------------------------------------------------------------- *DO,II,1,NComp TOLER(II, 1)= 0.1 $ TOLER(II, 2)= 0.1 *ENDDO ! ---------------------------------------------------------------------- ! Results Comparison ! ---------------------------------------------------------------------- COMPARA.MAC |
Results
| Label | Target | CivilFEM | Ratio | Tolerance |
| Sa(1)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(2)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(3)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(4)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(5)y | 539.45 | 539.45 | 1.000 | 0.1 |
| Sa(6)y | 666.59 | 666.59 | 1.000 | 0.1 |
| Sa(7)y | 753.11 | 753.11 | 1.000 | 0.1 |
| Sa(8)y | 897.13 | 897.12 | 1.000 | 0.1 |
| Sa(9)y | 955.89 | 955.89 | 1.000 | 0.1 |
| Sa(10)y | 990.71 | 990.71 | 1.000 | 0.1 |
| Sa(11)y | 1011.5 | 1011.5 | 1.000 | 0.1 |
| Sa(12)y | 1013.4 | 1013.4 | 1.000 | 0.1 |
| Sa(13)y | 974.82 | 974.82 | 1.000 | 0.1 |
| Sa(14)y | 913.8 | 913.8 | 1.000 | 0.1 |
| Sa(15)y | 731.34 | 731.34 | 1.000 | 0.1 |
| Sa(16)y | 579.77 | 579.77 | 1.000 | 0.1 |
| Sa(17)y | 340.9 | 340.9 | 1.000 | 0.1 |
| Sa(18)y | 224.94 | 224.94 | 1.000 | 0.1 |
| Sa(19)y | 117.43 | 117.43 | 1.000 | 0.1 |
| Sa(20)y | 72.3 | 72.3 | 1.000 | 0.1 |
| Sa(1)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(2)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(3)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(4)y | 392.6 | 392.6 | 1.000 | 0.1 |
| Sa(5)y | 539.44 | 539.45 | 1.000 | 0.1 |
| Sa(6)y | 666.59 | 666.59 | 1.000 | 0.1 |
| Sa(7)y | 753.14 | 753.11 | 1.000 | 0.1 |
| Sa(8)y | 897.13 | 897.12 | 1.000 | 0.1 |
| Sa(9)y | 955.89 | 955.89 | 1.000 | 0.1 |
| Sa(10)y | 990.72 | 990.71 | 1.000 | 0.1 |
| Sa(11)y | 1011.5 | 1011.5 | 1.000 | 0.1 |
| Sa(12)y | 1013.4 | 1013.4 | 1.000 | 0.1 |
| Sa(13)y | 974.86 | 974.82 | 1.000 | 0.1 |
| Sa(14)y | 913.84 | 913.8 | 1.000 | 0.1 |
| Sa(15)y | 731.36 | 731.34 | 1.000 | 0.1 |
| Sa(16)y | 579.76 | 579.77 | 1.000 | 0.1 |
| Sa(17)y | 340.9 | 340.9 | 1.000 | 0.1 |
| Sa(18)y | 224.93 | 224.94 | 1.000 | 0.1 |
| Sa(19)y | 117.39 | 117.43 | 1.000 | 0.1 |
| Sa(20)y | 72.3 | 72.3 | 1.000 | 0.1 |
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