摘要
为研究敦煌莫高窟彩塑在罕遇地震下的安全性,根据其内部构造特点,建立从内到外分别由木骨架层、芦苇捆扎层、粗泥层和细泥层组成的精细化有限元模型,通过扫频试验与模态分析结果对比,验证了所建有限元模型能够反应实际彩塑的动力特性。在此基础上计算罕遇地震作用下的响应,通过对模型的应力、位移和加速度结果的分析,评价彩塑的抗震性能。结果表明:罕遇地震下,站姿模型最大应力仍在允许范围内,但已接近破坏值,最容易出现破坏的地方主要为模型腿部以下区域、脖子周围以及上半身与手臂相连接部分;坐姿模型最大应力则发生在后背下部与底座连接的地方,其值超出了粗泥层和细泥层的抗拉强度,出现拉伸破坏。二者最大响应点均位于模型顶部,坐姿的响应小于站姿。可以认为在罕遇地震作用下彩塑存在损坏风险。
Painted sculptures of Dunhuang Mogao Grottoes are important constituents of Dun- huang＇s cultural art. To study the safety of painted sculptures under rare earthquakes, the finite element models were built according to internal structure of painted sculptures, which are made of wooden frame, reed-padded layer, coarse clay layer and fine clay layer from internal to exter- nal. By comparing sweep frequency experiment results with modal analysis results, it is proved that the finite element models can reflect the dynamic performance of painted seulptures. On the basis of this, the response of painted sculptures under rare earthquakes was calculated, the re- sults of model＇s stress, displacement and acceleration were analyzed, and the earthquake-resist- ant performance of painted sculptures was evaluated. The results show under rare earthquakes the standing posture model＇s maximum stress is within permitted range, but it is close to failure value. The positions in which standing posture model appear damage are below model＇s leg region, around neck and joint of arm and upper half body~ the maximum stress appears in the joint of sitting posture model＇s back and base. The value exceeds tensile strength, tensile failure occurs. The maximum response spots are tops of models. The response of sitting posture is less than standing posture. It is considered that there is a risk of damage to painted sculptures under rare earthquake.
出处
《防灾减灾工程学报》
CSCD
北大核心
2017年第2期201-207,共7页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家科技支撑计划课题项目(2013BAK01B01)资助
关键词
敦煌莫高窟
彩塑
罕遇地震
动力响应
数值模拟
Dunhuang Mogao Grottoes
painted sculptures
rare earthquake
dynamic responses
numerical simulation
作者简介
李利莎（1979-），男，助理研究员，硕士。主要从事工程震动和数值计算研究。Email：11s79@163．com
