石窟逆向建模方法研究与动力稳定性分析

Finite Element Modeling Method and Seismic Performance Analysis of Grottoes Based on Point Cloud Data

为研究石窟的抗震性能,提出了一种基于点云数据的逆向建模方法。以某石窟三维激光扫描数据为基础,实现了复杂石窟从现实空间的物理实体到虚拟空间的高精度三维有限元分析模型的构建。基于ABAQUS开展了石窟在自重、X向地震作用下的窟体应力应变特征、加速度与位移响应的分析。结果表明:石窟在自重及小震作用下处于弹性状态;大震作用下窟体产生塑性变形且拱脚出现拉伸破坏;在小震作用下,窟体的最大加速度、位移响应分别为3.94 m/s^(2)、13 mm;在大震作用下,窟体的最大加速度、位移响应分别为18.41 m/s^(2)、66 mm。基于数值模拟结果,提出了关注石窟脆弱部位的地震响应和加强石窟振动监测与长期稳定性监测3条建议,旨在为石窟的预防性保护提供技术支撑。

In order to study the stability and seismic performance of grottoes,a method of reverse modeling is proposed.Based on the 3D laser scanning data of a grotto,a high-precision 3D finite element analysis model of complex grottoes from the physical entity of real space to the virtual space is constructed.Based on ABAQUS,the gravity and seismic dynamic simulation of the grotto are carried out,and the stress and strain characteristics,acceleration response and displacement response of grotto are analyzed.The results show that the grotto is in an elastic state under the effect of gravity and frequent earthquake.Under the effect of rare earthquake,the grotto appears plastic deformation and the arch foot appeared tensile failure.Under the effect of frequent earthquake,the grotto's maximum acceleration and displacement responses were 3.94 m/s^(2) and 13mm,respectively.Under the effect of rare earthquake,the grotto's maximum acceleration and displacement responses were 18.41 m/s^(2) and 66mm,respectively.Based on the seismic response of grottoes,three suggestions are put forward,including paying attention to the response of vulnerable parts of grottoes under the effect of earthquake,and strengthening seismic and artificial vibration monitoring of grottoes,in order to provide technical support for further monitoring and preventive protection of grottoes.