基于离散单元法和物理引擎的结构连续倒塌可视化模拟

Visual simulation for structure continuous collapse based on discrete element method and physical engine

目前强离散性、大位移、大变形的倒塌全过程求解是结构计算分析的瓶颈,而离散单元法以理论力学为基础,基于刚体运动学和动力学方程,可有效实现结构全过程倒塌可视化模拟。运用Blender平台实现建筑结构的三维可视化建模及倒塌场景的可视化渲染;BCB(Bullet Constraints Builder)完成结构梁板柱构件的离散及刚体间约束的建立;物理引擎计算刚体间碰撞过程并"实时"更新刚体运动轨迹,三者协同作用实现倒塌全过程可视化模拟。模拟结果表明:所用方法适用于结构大变形模拟,可实现结构从弹性、弹塑性直至倒塌破坏的全过程可视化模拟,后续研究可为结构连续倒塌破坏机理的分析及人员逃生路径和搜救人员营救路线的选择提供科学指导。

Solving the whole collapse process of a structure with strong discreteness,large displacements and large deformations is a bottleneck of structural calculation analysis.Here,based on the theoretical mechanics,rigid body kinematics and dynamic equations,the discrete element method was used to effectively realize a visualization simulation for a structure’s whole collapse process.It was shown that Blender platform is used to realize a structure’s 3D visualization modeling and visual rendering of collapsed scene;the bullet constraints builder(BCB)is used to complete discretization of a structure’s beam-slab-column components and establishment of constraints among rigid-bodies;the physical engine is used to calculate collision process between rigid bodies,and update a rigid-body motion trajectory in real time;the synergy of the three realizes the visualization simulation of collapse process.Simulation results showed that the proposed method is suitable for large deformation simulation of structures and can realize visual simulation of the whole process from elasticity,elasticity-plasticity to collapse failure;the following study will provide a scientific guidance for the analysis of structure continuous collapse failure mechanism and the selection of evacuees’escape route and persons’rescue one.