摘要(英) |
According to past experience, when the structure comes to nonlinearity, the calculation is time-consuming, because of the complexity calculations. To solve the time-consuming problem of the traditional finite element analysis, this research introduces the Implicit decoupled finite element method (IDFEM) to solve the equation of motion and derives a series of elements for numerical analysis. In the same model basis and consistent analysis results, we compare the efficiency and accuracy between the implicit decoupled finite element method and the traditional finite element method.
In the past, when nonlinear dynamic analysis was executed, the stiffness-proportional damping force of the traditional finite element method could not change the stiffness according to the current state, which caused the structure to react to the unrealistic damping force. In reality, if the structure enters into yield, the structural system needs to dissipate energy through greater displacement, so that the displacement response of the analysis using the initial stiffness is smaller than in reality.
This research develops new three-dimensional elements and new functions in Implicit decoupled finite element method (IDFEM). The new element is link element, including linear spring and bilinear spring, hook plastic spring, gap plastic spring. The new function is using a bilinear spring to simulate a plastic hinge, which add the stiffness-proportional damping force changed by the stiffness change is added to the program to remove unrealistic damping force and make the analysis result more realistic. In the program, you can use the initial stiffness or the current stiffness to calculate the stiffness-proportional damping force for nonlinear analysis. The new element and the program’s correctness are verified by comparing calculation examples with the commercial finite element analysis software SAP2000 and ABAQUS. |
參考文獻 |
[1] Lee, T.Y., Chung, K.J. and Chang, H., “A new procedure for nonlinear dynamic analysis of structures under seismic loading based on equivalent nodal secant stiffness”, International Journal of Structural Stability and Dynamics, 18(3), 1850043, 2018.
[2] Lee, T.Y., Chung, K.J. and Chang, H. “A new implicit dynamic finite element analysis procedure with damping included.”, Engineering Structures, 147, pp. 530-544, 2017.
[3] 鍾昆潤,「非耦合隱式動力有限元素分析及其於結構崩塌分析之應用」,國立中央大學土木系博士論文,2018。
[4] Klaus- Jürgen Bathe, Mirza M. Irfan Baig, “On a composite implicit time integration procedure for nonlinear dynamics”, Computers and Structures, 2005.
[5] Klaus- Jürgen Bathe, “Conserving energy and momentum in nonlinear dynamics: A simple implicit time integration scheme”, Computers and Structures, 2007.
[6] Klaus-Jürgen Bathe, Gunwoo Noh, “Insight into an implicit time integration scheme for structural dynamics”, Computers and Structures, 2012.
[7] H. M. Hilber, T. J. R. Hughes, and R. L. Taylor. “Improved numerical dissipation for time integration algorithms in structural dynamics”, Earthquake Engineering and Structural Dynamics, 5,pp.283–292, 1977.
[8] Farzin Zareian and Ricardo A.Medina, “A practical method for proper modeling of structural damping in inelastic plane structural systems”, Computers and Structures, 2010
[9] D. Bernal, “Viscous damping in inelastic structural response”, ASCE J Struct Eng, 120(4), pp. 1240-1254,1994
[10] Medina RA, Krawinkler H. “Seismic demands for nondeteriorating frame structures and their dependence on ground motions”, PEER Report, 2003/15, 2004.
[11] J.F. Hall, “Problems encountered from the use (or misuse) of Rayleigh damping”, Earthquake Engineering and Structural Dynamics, 35 (5), pp. 525-545, 2005 |