在线混合实验系统开发及其在环梁节点研究中的应用
发布时间：2018-07-31 10:57
【摘要】：地震是破坏力最强的一种自然灾害之一。精确再现建筑结构的地震响应对于提高结构的抗震能力，防止建筑结构在地震中倒塌具有重要的意义。常规再现结构地震响应的方法包括数值模拟和物理实验，这两种方法通常能得到较为精确的结果，但是也都有一定的局限性。混合在线实验技术能够充分利用数值模拟和物理实验的优势，即：利用数值模拟技术建立结构的运动平衡方程，而通过物理实验获得结构的恢复力特性，可以精确有效地模拟结构的地震响应，是一种非常有前途的技术。本研究开发了一种结合有限元软件和子结构技术的新型混合在线实验系统,本论文重点关注如何改进在线混合实验中数值子结构的模拟精度。系统将用户子程序接口VDISP作为主控程序和ABAQUS/Explicit模块的接口，通过此结构向ABAQUS/Explicit模块输入目标位移并得到反作用力。文中之所以采用ABAQUS/Explicit模块，，而不是ABAQUS/Standard模块是因为，复杂结构容易出现收敛性问题，而混合仿真系统中由于包括了物理实验，收敛性问题是不能被接受的，因而采用显式数值方法来有效避免隐式数值方法中存在的收敛性问题。此系统无须迭代，因此非常适合进行物理实验。另外，此系统的开发无须改变有限元程序复杂且难以获得的代码，对于工程应用很有吸引力。本系统采用了分离式实验系统框架。数值积分方法采用了Operator-Splitting（OS）方法。数据传输基于Socket网络数据传输机制。 为了验证系统的有效性，本文利用该实验系统模拟了一个简单框架在地震下的响应，并将此响应与传统的有限元分析方法进行对比。对比结果证实了此系统的有效性和正确性。此外，本文还研究了影响实验系统有效性的重要参数，具体包括：时间步长、加载时间、质量调整以及材料阻尼。研究表明，为了获得准确的仿真结果，加载时间应等于总时间且应大于结构周期2~3倍，质量调整和材料阻尼有助于增大满足稳定条件的时间增量步，从而提高系统的计算速度。最后，研究中还运用该系统模拟环梁节点的复杂钢框架地震响应，基于对试样循环加载实验的结果，建立了环梁节点的精细有限元模型，并利用该有限元模型对环梁节点进行了参数分析，使其能够满足强节点弱构件的要求。模拟结果表明，本文提出的系统可以较好模拟采用了环梁节点的复杂钢框架的地震响应。
[Abstract]:Earthquake is one of the most destructive natural disasters. It is of great significance to accurately reproduce the seismic response of building structure to improve the seismic capacity of the structure and to prevent the building structure from collapsing in the earthquake. The conventional methods for reproducing structural seismic responses include numerical simulation and physical experiments. These two methods can usually obtain more accurate results, but both of them have some limitations. The hybrid on-line experimental technique can make full use of the advantages of numerical simulation and physical experiment, that is, the motion balance equation of structure can be established by using numerical simulation technique, and the restoring force characteristic of structure can be obtained by physical experiment. It is a promising technique to simulate the seismic response of structures accurately and effectively. In this paper, a new hybrid on-line experimental system combining finite element software and substructure technology is developed. This paper focuses on how to improve the simulation accuracy of numerical substructures in online hybrid experiments. The user subroutine interface (VDISP) is used as the interface between the main control program and the ABAQUS/Explicit module, and the target displacement is input to the ABAQUS/Explicit module through this structure and the reaction force is obtained. In this paper, the ABAQUS/Explicit module, not the ABAQUS/Standard module, is used because the complex structure is prone to convergence problems, and the convergence problem is unacceptable in the hybrid simulation system due to the physical experiments included. So the explicit numerical method is used to avoid the convergence problem in implicit numerical methods. The system does not need iteration, so it is very suitable for physical experiments. In addition, the development of the system does not need to change the finite element program complex and difficult to obtain code, it is very attractive for engineering applications. This system adopts the frame of separate experiment system. Operator-Splitting (OS) method is used in numerical integration method. Data transmission is based on Socket network data transmission mechanism. In order to verify the effectiveness of the system, this paper uses the experimental system to simulate the response of a simple frame under earthquake, and compares this response with the traditional finite element analysis method. The validity and correctness of the system are verified by the comparison results. In addition, important parameters affecting the effectiveness of the experimental system are studied, including: time step, loading time, mass adjustment and material damping. The results show that, in order to obtain accurate simulation results, the loading time should be equal to the total time and should be 3 times larger than the structural period. The quality adjustment and material damping can increase the time increment step to meet the stability conditions, thus improving the calculation speed of the system. Finally, the system is used to simulate the seismic response of the ring beam joints in complex steel frames. Based on the experimental results of cyclic loading on the specimens, the fine finite element model of the ring beam joints is established. The finite element model is used to analyze the parameters of ring beam joints, which can meet the requirements of strong joints and weak members. The simulation results show that the proposed system can better simulate the seismic response of the complex steel frame with ring beam joints.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU317
本文编号：2155370
[Abstract]:Earthquake is one of the most destructive natural disasters. It is of great significance to accurately reproduce the seismic response of building structure to improve the seismic capacity of the structure and to prevent the building structure from collapsing in the earthquake. The conventional methods for reproducing structural seismic responses include numerical simulation and physical experiments. These two methods can usually obtain more accurate results, but both of them have some limitations. The hybrid on-line experimental technique can make full use of the advantages of numerical simulation and physical experiment, that is, the motion balance equation of structure can be established by using numerical simulation technique, and the restoring force characteristic of structure can be obtained by physical experiment. It is a promising technique to simulate the seismic response of structures accurately and effectively. In this paper, a new hybrid on-line experimental system combining finite element software and substructure technology is developed. This paper focuses on how to improve the simulation accuracy of numerical substructures in online hybrid experiments. The user subroutine interface (VDISP) is used as the interface between the main control program and the ABAQUS/Explicit module, and the target displacement is input to the ABAQUS/Explicit module through this structure and the reaction force is obtained. In this paper, the ABAQUS/Explicit module, not the ABAQUS/Standard module, is used because the complex structure is prone to convergence problems, and the convergence problem is unacceptable in the hybrid simulation system due to the physical experiments included. So the explicit numerical method is used to avoid the convergence problem in implicit numerical methods. The system does not need iteration, so it is very suitable for physical experiments. In addition, the development of the system does not need to change the finite element program complex and difficult to obtain code, it is very attractive for engineering applications. This system adopts the frame of separate experiment system. Operator-Splitting (OS) method is used in numerical integration method. Data transmission is based on Socket network data transmission mechanism. In order to verify the effectiveness of the system, this paper uses the experimental system to simulate the response of a simple frame under earthquake, and compares this response with the traditional finite element analysis method. The validity and correctness of the system are verified by the comparison results. In addition, important parameters affecting the effectiveness of the experimental system are studied, including: time step, loading time, mass adjustment and material damping. The results show that, in order to obtain accurate simulation results, the loading time should be equal to the total time and should be 3 times larger than the structural period. The quality adjustment and material damping can increase the time increment step to meet the stability conditions, thus improving the calculation speed of the system. Finally, the system is used to simulate the seismic response of the ring beam joints in complex steel frames. Based on the experimental results of cyclic loading on the specimens, the fine finite element model of the ring beam joints is established. The finite element model is used to analyze the parameters of ring beam joints, which can meet the requirements of strong joints and weak members. The simulation results show that the proposed system can better simulate the seismic response of the complex steel frame with ring beam joints.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU317
【参考文献】
相关期刊论文 前1条
1 汪训流;陆新征;叶列平;;往复荷载下钢筋混凝土柱受力性能的数值模拟[J];工程力学;2007年12期
本文编号：2155370
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