罕遇地震下敦煌莫高窟彩塑动力响应数值模拟

发布时间：2018-04-30 03:03

本文选题：敦煌莫高窟 + 彩塑　；参考：《防灾减灾工程学报》2017年02期

【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。
[Abstract]:In order to study the safety of color sculptures in Dunhuang Mogao Grottoes under rare earthquakes, a fine finite element model composed of wood skeleton layer, Reed binding layer, coarse mud layer and fine mud layer from inside to outside was established according to its internal structural characteristics. By comparing the results of frequency sweep test and modal analysis, it is verified that the finite element model can reflect the dynamic characteristics of the actual color plastic. On this basis, the response under rare earthquake is calculated, and the seismic performance of color plastic is evaluated by analyzing the results of stress, displacement and acceleration of the model. The results show that the maximum stress of the standing posture model is still within the allowable range under rare earthquakes, but it is close to the damage value. The most vulnerable areas are the area below the leg of the model, the part around the neck and the upper body connected to the arm. The maximum stress of the model occurs at the place where the bottom of the back is connected with the base, which exceeds the tensile strength of the thick mud layer and the fine mud layer, resulting in tensile failure. The maximum response points of both are located at the top of the model, and the response of sitting position is smaller than that of standing position. It can be considered that there is a risk of damage to color plastic under rare earthquake.
【作者单位】：总参工程兵科研三所;敦煌研究院;
【基金】：国家科技支撑计划课题项目(2013BAK01B01)资助
【分类号】：K879.3;TU311.3

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