摘要
塑性铰模型计算效率高,可快速获得结构宏观破坏模式,韧性断裂损伤模型从微观机制揭示钢材的断裂机理,可较准确预测钢材的断裂行为。为此,该文基于杆系离散元理论,将两者联合建立构件断裂模拟算法,既具有计算效率高的优势又保证构件断裂模拟的精度。首先介绍杆系离散元法的基本理论,以及宏观塑性铰模型和微观韧性断裂损伤模型具体计算流程;然后给出将两者联合分析的具体实施策略,即以接触截面边缘最不利点处的应力作为整个截面的应力状态,进而调用韧性断裂损伤模型。最后采用Fortran语言编制相应的分析程序,并通过悬臂梁断裂算例和单层网壳振动台倒塌试验,验证该算法对模拟杆件断裂行为的可行性和有效性。杆系离散元法模拟构件断裂时,截面发生开裂,颗粒间发生脱离是一个自然的过程,无需其他任何修正即可实现结构由连续体状态向断裂后非连续体状态过渡,与有限元方法相比,不存在网格畸变重划分、迭代不收敛的问题,更具计算优势,为大跨空间网壳结构倒塌破坏分析提供新的计算手段。
The plastic hinge model has high calculation efficiency and can quickly obtain the macroscopic failure mode of the structure.The ductile fracture damage model may reveal the fracture mechanism of steel from the microscopic mechanism,and can accurately predict the fracture behavior of steel.Therefore,based on the member discrete element theory,the two models may be combined to establish a member fracture simulation algorithm,which not only has the advantages of high computational efficiency,but also ensures the accuracy of member fracture simulation.Firstly,the basic theory of the member discrete element method is introduced,and the specific calculation processes of the macroscopic plastic hinge model and the microscopic ductile fracture damage model are presented.Secondly,the specific implementation strategy of the joint analysis of the two models is given,that is,the stress at the most unfavorable point on the edge of the contact section is taken as the stress state of the entire section,and then the ductile fracture damage model is applied.Finally,the analysis program is coded by Fortran Language,and the feasibility and effectiveness of the algorithm for simulating the member fracture behavior are verified by a cantilever beam fracture example and the shaking table collapse test on a single-layer spherical reticulated shell.When the member discrete element method is used to simulate the fracture of the component,the cracking of the cross section and the separation between the particles is a natural process,and the transition of the structure from the continuum state to the discontinuous state after the fracture can be realized without any other corrections.It is superior to the finite element method in computations.For example,there is no mesh refinement problem due to mesh distortion or the non-convergence problem of iteration,and hence it provides a new calculation means for the collapse and failure analysis of large-span space reticulated shell structures.
作者
叶继红
许强
Ye Jihong;Xu Qiang(Jiangsu Key Laboratory Environmental Impact and Structural Safety in Engineering,China University of Mining and Technology,Xuzhou 221116,China;Xuzhou Key Laboratory for Fire Safety of Engineering Structures,China University of Mining and Technology,Xuzhou 221116,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2024年第1期1-9,共9页
China Civil Engineering Journal
基金
国家自然科学基金面上项目(51978655)。
关键词
杆系离散元法
断裂
单层网壳结构
塑性铰模型
韧性断裂损伤模型
member discrete element method
fracture
single-layer reticulated shell structure
plastic hinge model
ductile fracture damage model
