Flexural slip behaviors of buckling folds in elasto-plastic layer revealed by numerical analysis
Date Issued
2009
Date
2009
Author(s)
Tang, Han-Shin
Abstract
During diastrophism, the plates collide with each other has caused a bending of the geological structure which is called fold. In Previous studies have been made of different material combinations formation of single-layer fold of the theoretical solution and numerical simulation methods to validate the comparison, but which at the junction formation is assumed to be the case without the interface and the material does not take the effect of yield behavior, for real geotectonic material to understand its interface behavior may still missing, such as flexural slip result in fold axis having cavities and chevron fold of plastic hinge, as well as the relationship between the timing of rock layer yield and the theoretical solution of single-layer fold, so this study was to build the basis of an earlier, and then explore the influence of the interfacial properties between layers of overlying strata and confining pressure on elasto-plastic folds. In this study, using numerical analysis to discuss the impact factor and then taking the results of the analysis compare with the theoretical solution for determine the impact of the trend. To select ABAQUS software as simulation tool, and using the uniform force to give the confining pressure of the depth of rock strata; using friction property to simplify the complexity of the interface bonding behavior of strata; using displacement control the border to simulate the process of strata by extrusion. The simulation results of elastic folds, the wavelength of buckling fold is similar to the theoretical solution, it means that friction interface and the confining pressure of overlying strata is not significantly affected, but during process of its extrusion to form single-frequency dual- frequency waveform, fold axis will be arose cavities by flexural-slip folding, and the interfacial properties between layers will restrict the relative slip occurred between rock layer and matrix and change the adjustment deformation behavior of fold; confining pressure of overlying strata will inhibit the characteristics of high-frequency waveforms of dual-frequency waveform fold, as well as the degree of emergence cavities. The simulation results of elasto-plastic folds, the friction interface between layers there is little impact on buckling behavior of rock layer; but confining pressure of overlying strata for the timing of the elasto-plastic materials yield will determine the post-buckle behavior of rock layer, when the rock layer first yield and then buckling will not be able to form a fold, which means rock layer will fracture from a weak surface during the moment of buckling; and when the rock layer yield after buckling, the formation of the fold will have different adjustment and deformation caused by the place and degree of yield. It can be inferred from the study, with the time delay of rock layer yield will be observed that the fault then, duplex, single-frequency waveform folds and dual-frequency waveform folds.
Subjects
numerical simulation
flexural slip
cavity
chevron fold
plastic hinge
interfacial properties
confining pressure
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-R96521114-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):997d6be383aa7e77c04192ace6617fb9