CFVR4701 - CALTRANS: Seismic Analysis X-axis
Seismic Analysis on a 1 DOF beam according to CALTRANS. (Soil profile type B)
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: CFVR4701.DAT
FINISH ~CFCLEAR,,1 NomFile='CFVR4701' /TITLE, %NomFile%, CALTRANS: Seismic Analysis X-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 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 pi=3.141592654 ! Seismic Spectrum ~DEFSPEC,ALL,0.5,B1,0,5,1 ! ---------------------------------------------------------------------- ! 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,ARG1,1,20,1 /PREP7 ~CFGET,AR26,SEISM,,SPEC,TH,,ARG1,1 ! Period ! Labels LABEL(ARG1,1) = 'Sa(%ARG1%)x' LABEL(20+ARG1,1) = 'Sa(%ARG1%)x' AR25=AR20*AR22/L AR27=AR25*(AR26/(2*pi))**2 ! Mass applied at end R,2,AR27 TYPE,2 MAT, 1 REAL,2 EN,2,10 FINISH /SOLU ! Solution ! --------------------------------------------------------------------- ! Displacements D,1,,,,,,ALL D,10,,,,,,UY,UZ,ROTX,ROTY,ROTZ ~MODLSOL,1 ~CMBMOD,HORIZONT,NONE,NONE,0,0.0001 ! Query results *GET,ARG5,NODE,10,U,X ! Correct values VALUE(20-ARG1+1,1)=ARG5*AR25/AR27 ! Aceleration ! Obtained values ~CFGET,VALUE(20-ARG1+1,2),SEISM,,SPEC,SDH,,ARG1,1 ! Y components of linear horizontal spectrum ~CFGET,VALUE(40-ARG1+1,2),SEISM,,SPEC,SDH,,ARG1,1 ! Y components of linear horizontal 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)= 54.83790 VALUE(39,1)= 88.71016 VALUE(38,1)= 161.30166 VALUE(37,1)= 240.20095 VALUE(36,1)= 402.40705 VALUE(35,1)= 559.96750 VALUE(34,1)= 812.16571 VALUE(33,1)= 940.95588 VALUE(32,1)= 1067.93200 VALUE(31,1)= 1135.44433 VALUE(30,1)= 1150.40783 VALUE(29,1)= 1135.88059 VALUE(28,1)= 1110.96106 VALUE(27,1)= 1045.42528 VALUE(26,1)= 957.99285 VALUE(25,1)= 816.50328 VALUE(24,1)= 651.83552 VALUE(23,1)= 490.79430 VALUE(22,1)= 490.79430 VALUE(21,1)= 490.79430 ! 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)x | 490.79 | 490.79 | 1.000 | 0.1 |
| Sa(2)x | 490.79 | 490.79 | 1.000 | 0.1 |
| Sa(3)x | 490.79 | 490.79 | 1.000 | 0.1 |
| Sa(4)x | 651.87 | 651.87 | 1.000 | 0.1 |
| Sa(5)x | 816.49 | 816.49 | 1.000 | 0.1 |
| Sa(6)x | 957.95 | 957.95 | 1.000 | 0.1 |
| Sa(7)x | 1045.5 | 1045.5 | 1.000 | 0.1 |
| Sa(8)x | 1111 | 1111 | 1.000 | 0.1 |
| Sa(9)x | 1135.9 | 1135.9 | 1.000 | 0.1 |
| Sa(10)x | 1150.4 | 1150.4 | 1.000 | 0.1 |
| Sa(11)x | 1135.4 | 1135.4 | 1.000 | 0.1 |
| Sa(12)x | 1067.9 | 1067.9 | 1.000 | 0.1 |
| Sa(13)x | 940.98 | 940.98 | 1.000 | 0.1 |
| Sa(14)x | 812.17 | 812.17 | 1.000 | 0.1 |
| Sa(15)x | 559.96 | 559.95 | 1.000 | 0.1 |
| Sa(16)x | 402.41 | 402.41 | 1.000 | 0.1 |
| Sa(17)x | 240.25 | 240.25 | 1.000 | 0.1 |
| Sa(18)x | 161.28 | 161.28 | 1.000 | 0.1 |
| Sa(19)x | 88.682 | 88.682 | 1.000 | 0.1 |
| Sa(20)x | 54.838 | 54.838 | 1.000 | 0.1 |
| Sa(1)x | 490.79 | 490.79 | 1.000 | 0.1 |
| Sa(2)x | 490.79 | 490.79 | 1.000 | 0.1 |
| Sa(3)x | 490.79 | 490.79 | 1.000 | 0.1 |
| Sa(4)x | 651.84 | 651.87 | 1.000 | 0.1 |
| Sa(5)x | 816.5 | 816.49 | 1.000 | 0.1 |
| Sa(6)x | 957.99 | 957.95 | 1.000 | 0.1 |
| Sa(7)x | 1045.4 | 1045.5 | 1.000 | 0.1 |
| Sa(8)x | 1111 | 1111 | 1.000 | 0.1 |
| Sa(9)x | 1135.9 | 1135.9 | 1.000 | 0.1 |
| Sa(10)x | 1150.4 | 1150.4 | 1.000 | 0.1 |
| Sa(11)x | 1135.4 | 1135.4 | 1.000 | 0.1 |
| Sa(12)x | 1067.9 | 1067.9 | 1.000 | 0.1 |
| Sa(13)x | 940.96 | 940.98 | 1.000 | 0.1 |
| Sa(14)x | 812.17 | 812.17 | 1.000 | 0.1 |
| Sa(15)x | 559.97 | 559.95 | 1.000 | 0.1 |
| Sa(16)x | 402.41 | 402.41 | 1.000 | 0.1 |
| Sa(17)x | 240.2 | 240.25 | 1.000 | 0.1 |
| Sa(18)x | 161.3 | 161.28 | 1.000 | 0.1 |
| Sa(19)x | 88.71 | 88.682 | 1.000 | 0.1 |
| Sa(20)x | 54.838 | 54.838 | 1.000 | 0.1 |
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