EI、Scopus 收录

 引用本文: 章小龙, 李小军, 陈国兴, 周正华. 黏弹性人工边界等效载荷计算的改进方法[J]. 力学学报, 2016, 48(5): 1126-1135.
Zhang Xiaolong, Li Xiaojun, Chen Guoxing, Zhou Zhenghua. AN IMPROVED METHOD OF THE CALCULATION OF EQUIVALENT NODAL FORCES IN VISCOUS-ELASTIC ARTIFICIAL BOUNDARY[J]. Chinese Journal of Theoretical and Applied Mechanics, 2016, 48(5): 1126-1135.
 Citation: Zhang Xiaolong, Li Xiaojun, Chen Guoxing, Zhou Zhenghua. AN IMPROVED METHOD OF THE CALCULATION OF EQUIVALENT NODAL FORCES IN VISCOUS-ELASTIC ARTIFICIAL BOUNDARY[J]. Chinese Journal of Theoretical and Applied Mechanics, 2016, 48(5): 1126-1135.

## AN IMPROVED METHOD OF THE CALCULATION OF EQUIVALENT NODAL FORCES IN VISCOUS-ELASTIC ARTIFICIAL BOUNDARY

• 摘要: 黏弹性人工边界在场地地震反应和结构-地基动力相互作用等问题的计算中已得到了广泛的应用.地震波在黏弹性人工边界中的输入是通过将地震波转化为作用于人工边界处的等效载荷来实现的.计算等效节点载荷的常规方法默认边界节点对应区域内的应力为均布力，但实际上该节点对应区域内的应力分布通常是不均匀的.本文在有限元方法结合黏弹性局部人工边界的显式时域波动方法的基础上，建立了无限域散射问题地震波等效载荷计算的一种改进方法.该方法采用细化网格与应力积分相结合的方法计算人工边界等效节点力，有效地降低了人工边界上等效节点力的计算误差.以不同角度入射地震波的二维算例为例，算例给出的波场位移云图和节点位移时程曲线验证了本文方法的有效性，其计算精度与网格尺寸和地震波入射角度密切相关，且网格越小、入射角度越小，计算精度越高.对于相同的网格尺寸，本文采用方法的计算精度明显高于常规方法，尤其是对于斜入射问题优势更为明显.

Abstract: The viscous-elastic artificial boundary is widely used in the analysis of site seismic response and dynamic structure-soil system interaction problems. Seismic input is usually taken as equivalent nodal forces incorporating in the viscous-elastic artificial boundary, and stress in the control area of any artificial boundary node in the conventional method is considered as uniform distribution. However, its distribution is actually uneven. An improved method is proposed for the seismic input of wave propagation scattering problem in infinite domain. In the proposed method, an viscous-elastic artificial boundary is first introduced; seismic input is considered as the equivalent node forces to be incorporated directly in these local boundaries, and the node force obtained using the mesh refinement process combining stress integration of adjacent node regions is changed along the artificial boundary nodes, and its computation error is effectively reduced; the two-dimensional wave propagation problem in time-domain is then solved using the explicit finite element method. The numerical simulation of two-dimensional finite element site models of wave propagation problem with various mesh sizes and incidence angles are presented to demonstrate the performance of the improved method in this paper. The simulating nephogram of wave propagation and values of response displacement show that the calculating precision of the improved method is closely related to the mesh size and wave incidence angle, and increases with decrease of the mesh size and incidence angle. The simulation result also shows that the calculating precision of the improved method is significantly higher than that of the conventional method in the case of the same mesh size and incidence angle.

/

• 分享
• 用微信扫码二维码

分享至好友和朋友圈