Collapse Analyze Of Reinforced Concrete Frame Structure Based On The Mechanical Hinge Theory

History and reality have shown that strong earthquake destroyed buildings that causes the major economic losses and destroys people’s lives. With the continuous development of construction in modern cities, there have been many newer and more complex structures; however, recently people pay more attention to the prevention of building collapse after having a strong visual impact of the damage from the seismic. How to prevent the structure from collapse when subjected to high intensity earthquake has also become a serious problem.Typically, before the collapse, the structure will enter elastoplastic stage, accompanied by a number of non-linear problems, for example, the frame structure will form a plastic hinge mechanism loss of kinetic stability. But plastic hinge moment actually can afford to be a kind of reverse recovery movement stable concept hinges and does not reflect the real structure to collapse from the deformation process. Professor Liu Xila has proposed a concept of a mechanical hinge, and described its ideological collapse judgment on the basis of qualitative definition. In China, there are a lot of scholars have also studied the collapse of the whole process, more use of ANSYS, ABAQUS, MSC.MARC other large general-purpose finite element software nonlinear strong non-linearity solving ability to analyze, but more stable implicit calculated using standard algorithms, which highly nonlinear analysis often encountered no convergence problems. The explicit integration method in this area has shown a strong advantage, including non-convergence test model, saving a lot of computer storage space, parallel technology to increase analysis speed; but it has more demanding to get a steady and precision result from explicit integration.In this paper, based on the qualitative research in mechanical hinge, verified the quantitative definition by using ABAQUS explicit analysis modules in component level and structure level; by Python secondary development, calculated some variables which are not support for ABAQUS to improve the implementation of general software; and use this theory in real one-span two story structure, to discuss the structural safety reserves, and other parameters. The main contents are as follows:1. Definition of Mechanical Hinges QuantizationIn-Depth analysis of the similarities and differences between plastic hinge and the mechanical hinge. Even though the plastic is an extension of damage, but clearly the root cause of collapse occurred is hinge mechanism. Based on mechanical hinge theory, it is determined at the component level to quantify the specific rules and definitions, and discusses the significance of the definition in the structure, and ultimately improve the mechanical hinge theory.2. Study CDP Model Explicit IntegrationSelecting ABAQUS/Explicit analysis module, and study of concrete beam-column nodes model based on CDP model by analyses research result of repeated horizontal loading. This model uses solid element simulation of concrete, steel truss element simulation, the interaction between the uses of embedded constraints, compared to the experimental those data are match perfectly. Based on quasi-static analysis, discussed the principles and techniques of Explicit analyze. Using mechanical hinge theory at component level to identify the critical moment of the order and the degradation of node hinges, as well as the validity of the quantization indice.3. Python’s secondary developmentThe most straightforward parameters in hinges definition is the unit angle or curvature, but usually it will be difficult to directly get the result in finite element software. So the use of Python’s secondary development for ABAQUS, developed a program for inspecting corner units, and could directly obtain normalized data and the order of overrun.4. Investigation Equivalent Unit ModelUsing an equivalent unit replacement node model approach to identify more realistic time and the order of a collapse which are very difficult to be solved by using geometric analysis. Investigated a collapse of a double-single-span frame structure, and discussed the relevant measures such as the amount of residual energy and security reserve coefficient.