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Jaeseong Bae @ on — Edited @ @ on
Hello,
I am using GEBT to analyze an isotropic cantilever beam subject to a tip bending moment, a well-known problem in the geometrically nonlinear analysis of beams.
The analysis conditions of the beam are given as follows.
- Cross-section: width (b) = 0.1in., height (h) = 0.01in.
- Beam length (L) = 10in.
- Young's modulus (E) = 1x10^7psi
- Poisson's ratio (nu) = 0.3
- Reference frame : Global frame (a1: axial direction, a2: lag direction, a3: flap direction)
- Tip bending moment: n x 2 x pi x EI_2 / L (The moment is acting about a2 axis, n is the loadfactor, EI_2 = b*h^3/12)
- Shear flexiblities are suppressed to be zeros for the analysis under Euler-Bernoulli level.
- GEBT (Rodriguez rotation parameters ver.) used for the analysis
As already known, the beam should form a circle when n = 1. However, GEBT fails to find the converged solution under that loadfactor.
For your information, I have posted my input file for this problem as follows.
0 100 10 # analysis_flag, niter, nstep
2 1 2 1 0 0 0 0 0 # nkp, nmemb, ncond_pt, nmate, nframe, ncond_mb, ndistrfun, ntimefun, ncurv
1 0 0 0
2 10 0 0
1 1 2 1 1 0 10 0 # memb_no, kp1, kp2, mate1, mate2, frame_no, nelem, curv_no
1
1 2 3 4 5 6
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
2
7 8 9 10 11 12
0 0 0 0 5.23598776E-02 0
0 0 0 0 0 0
0 0 0 0 0 0
1
1.00000000E-04 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00 7.80000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 1.20000000E+01 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 1.20000000E-01
The input file for the problem is attached.
I think I am missing something when making the input.
It would be grateful if someone leaves me a reply.
Thank you.
Best regards,
Jaeseong
input-001.zip
399 B Click to download
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