中文摘要：

应用Lyapunov指数法,对试验得到的深埋煤层应力松弛系统演化对应于各级应变水平的时间序列进行分析,科学重构相空间,得到了每一递进应变水平的相轨迹均不重复地围绕各自对应的历史应力中值而顺次演化。采用分形几何学方法进行时间序列分析,定量揭示出煤样应力松弛系统演化的各层次间自相似性,并部分反映了经典力学与非线性科学间的关系。得到了对应各级应变水平系统演化时间序列的非线性动力学评价指标,并判定深埋煤层应力松弛系统为复杂系统且具有典型混沌特征。深埋煤层应力松弛系统演化的混沌程度及复杂程度呈下降规律,煤体内部力学性质弱化因素与强化因素之间竞争最为激烈的阶段,其混沌程度最高,而宏观破坏后系统伴随最低的混沌程度及复杂程度。

英文摘要：

In this study, the Lyapunov index method is adopted to study time series under each loading strain level during the experiment on an evolving stress relaxation system of the deep coal seam. Through reconstructing phase space of deep seams, phase locus corresponding to each strain level presents an evolution on encircling its historic stress median no-repeatedly. By analyzing the time series with the fractal geometrics method, self similarities among different evolving stages of the stress relaxation system have been determined quantitatively. In addition, the relationship between classic mechanics and nonlinear science is also reflected. Nonlinear dynamical indexes of the evolving stress relaxation system are obtained to verify that it is a complicated system with typical chaotic properties. Moreover, the chaotic degree and complicated degree might descend with the development of the stress relaxation system of deep coal seams. It is found that the most obvious chaotic degree appears at the critical stage when the competition between softened factors and the enhanced ones for mechanical features of coal seam is the most drastic. Whereas after macroscopic failure the system shows the lowest chaotic and complicated degrees.