介质非均匀性对加卸载响应比峰值异常特征时间影响的数值研究

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	介质非均匀性对加卸载响应比峰值异常特征时间影响的数值研究
其他题名	NUMERICAL SIMULATION RESEARCH ON THE INFLUENCE OF MATERIAL HETEROGENEITY ON CHARACTERISTIC TIME OF LOAD/UNLOAD RESPONSE RATIO’S PEAK ABNORMITY
	张浪平; 李志雄; 尹祥础; 梁乃刚
发表期刊	工程力学
	2011-09-25
卷号	28 期号:9 页码:44-50,58
ISSN	1000-4750
摘要	加卸载响应比方法为非均匀脆性介质的灾变预测提供了新的思路,该方法用加载与卸载响应的差别来定量刻画介质的损伤演化过程。已有的岩石实验研究和地震震例研究,发现在岩石破裂或者地震发生之前,加卸载响应比都会出现异常明显的升高及回落,表明加卸载响应比峰值异常具有良好的灾变前兆意义。震例研究中发现,加卸载响应比峰值异常特征时间呈现区域特性。因此,首先用链网模型模拟了压缩载荷下非均匀脆性介质的损伤演化至破裂的过程,同样发现加卸载响应比在试样发生宏观破裂之前出现了峰值回落的现象,再次从数值计算的角度证明了加卸载响应比峰值的灾变前兆作用。其次重点考察了不同非均匀性程度试样的加卸载响应比演化情况,发现峰值出现到试样破裂发生的特征时间T_2与介质非均匀性程度指标Weibull指数m存在如此关系:m值越大,T_2值越小。表明介质的均匀性程度越高,特征时间T_2的值就越小,破裂发生也就越突然。该文得出的介质非均匀性程度与峰值异常特征时间的关系将为提高加卸载响应比地震预测的时间能力提供某些线索。
其他摘要	The Load/Unload Response Ratio(LURR) method is proposed as a new approach to predict the failure of heterogeneous brittle materials,namely using the ratio between response rates occurred during the time periods of loading and unloading to describe the process of damage evolution quantitatively.In laboratory studies and inspection of real earthquake cases we have found that the LURR time series climb to an anomalously high peak and then decrease rapidly prior to the rupture of the rock specimens or the occurrence of earthquakes,which demonstrates that peak values of the LURR time series possess good significance of a catastrophic failure prediction.We also find the characteristic time of LURR peak abnormity appears regional features.Thusly,firstly,we simulate the process of damage evolution to failure of rock specimens under compression on the basis of a Chain-Network Model and also find the appearance of a peak value and fall of the LURR value successively before the macro-failure of specimens,which validates that LURR’s peak value is a good precursor for catastrophic failure from the viewpoint of numerical simulation again.Furthermore,LURR evolutions of heterogeneous brittle specimens with different heterogeneity are investigated emphatically,and the heterogeneity of specimens is achieved by introducing Weibull distribution as a probability distribution function.It finds that the time gaps T2 between the peak values and the ruptures are influenced by Weibull modulus m used to describe the heterogeneous extent of the specimens.T2 will be smaller if m value is larger,which means the time gap T2 is smaller if the homogeneity of specimens is higher and the rupture will be also more abruptly.The research in this paper will provide some clues to improve the time accuracy in the earthquake prediction by using the LURR method. 更多
关键词	加卸载响应比链网模型灾变前兆非均匀脆性介质损伤演化
学科领域	力学
URL	查看原文
收录类别	EI ; CSCD
语种	中文
项目资助者	国家自然科学基金项目(41004018);中国地震局地震预测研究所基本科研业务专项项目(02092425)
CSCD记录号	CSCD:4327537
引用统计
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/44976
专题	非线性力学国家重点实验室
通讯作者	张浪平
推荐引用方式 GB/T 7714	张浪平,李志雄,尹祥础,等. 介质非均匀性对加卸载响应比峰值异常特征时间影响的数值研究[J]. 工程力学,2011,28,9,:44-50,58.
APA	张浪平,李志雄,尹祥础,&梁乃刚.(2011).介质非均匀性对加卸载响应比峰值异常特征时间影响的数值研究.工程力学,28(9),44-50,58.
MLA	张浪平,et al."介质非均匀性对加卸载响应比峰值异常特征时间影响的数值研究".工程力学 28.9(2011):44-50,58.

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