模糊集組成律之簡化模式發展及其有限元素法之分析應用

本研究發展簡化的模糊集組成律模式，並將此組成模型建立在有限元素法軟體PLAXIS中。模糊集組成律理論一開始是Klinsinski在1988年所提出，適用於模擬土壤或岩石的循環載重彈塑性行為，主要可應用於土壤液化與交通載重問題之研究。模糊集組成模型建立在臨界狀態土壤力學的架構下，可以用較少的參數、簡單的算式，模擬不規則載重與非線性膨脹的彈塑性行為。在使用木山層砂岩與越南石英砂的三軸試驗結果校正模型參數後，另外提出一些循環載重下的模擬範例，並嘗試以不同的組成來模擬剪脹行為。本研究亦將PLAXIS使用者自訂組成模型的功能作整理，將模糊集組成模型應用在PLAXIS中，並以三軸數值模型作驗證。經由數值分析結果顯示，此模糊集組成律簡化模型可以在PLAXIS中模擬出相符的應力應變與體積變化曲線。

關鍵字

模糊集塑性；組成模型；循環載重；有限元素分析； PLAXIS

並列摘要

This research presents a simplified cyclic plasticity model based on the concept of fuzzy set plasticity theory and its implementation in the geotechnical finite element software PLAXIS. The fuzzy set plasticity theory was first introduced by Klisinski in 1988 for simulating the behavior of sand under cyclic load. The model is capable of mimicking the elasto-plastic behaviors under non-proportional loading and nonlinear dilantancy under the framework of critical state soil mechanics, using a simple formulation and requiring fewer model parameters. The model was used to simulate the behaviors of rock and soil in this study. It was calibrated through a series of conventional traxial compression tests on the Mushan sandstone for modeling intact rock, as well as the conventional consolidated drained triaxial compression tests on Vietnam silica sand for mimicking sand. The stress-dilatnacy defined by Ueng and Lee was implemented in the simplified fuzzy set plasticity model. A procedure of implementing a user-defined soil model into PLAXIS is also described. The implementation of the user-defined simplified fuzzy set plasticity model was validated through the triaxial tests under monotonic loading with 3 different confining pressures in PLAXIS 2D. The simulation using the fuzzy model with 7 parameters shows a reasonable stress-strain and volume change curves, which were compared with the simulation run directly in MATLAB.

並列關鍵字

Fuzzy set plasticity ； constitutive model ； cyclic loading ； finite element analysis ； PLAXIS

參考文獻

[1] Klisinski, M. (1988). Plasticity theory based on fuzzy sets. Journal of Engineering Mechanics, ASCE, 114(4), 563-582.

[2] Klisinski, M., Abifadel, N., Runesson, K., and Sture, S. (1991). Modelling of the behavior of dry sand by an elasto-plastic fuzzy set model. Computers and Geotechnics, 11(3), 229-261.

[3] Arduino, P. and Macari, E. J. (2001). Implementation of porous media formulation for geomaterials. Journal of Engineering Mechanics, ASCE, 127(2), 157–166.

[5] Bao, Y., and Sture, S. (2010). Application of a kinematic-cyclic plasticity model in simulating sand liquefaction. International Journal of Advances in Engineering Sciences and Applied Mathematics, 2(3), 119-124

[6] Bao, Y., and Sture, S. (2011). Numerical modeling of cyclic mobility based on fuzzy-set concepts in plasticity theory. Computers and Geotechnics, 38(3), 375-382.

國際替代計量

模糊集組成律之簡化模式發展及其有限元素法之分析應用

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