Research On Multilevel Damage Model Of Multi-Ribbed Composite Wall

Accurate description of the damage degree of the structure and the component is the core problem of performance based seismic design. Multi-ribbed composite wall (MRCW) structure is a new structural system, characterized by good aseismic performance. At present, much progress has been achieved in previous study through a lot of systematic tests and theoretical researches on MRCW. However, further research on damage model of MRCW should be made.The multi-ribbed composite wall is taken as the research object in this paper. Combined with the structural characteristics, the damage model of multi-ribbed composite wall is studied by numerical simulation method.The main contents are as following:1. Damage finite element model of multi-ribbed composite wall is established. In this numerical model, the damage factor of the material constitutive model of concrete and filled block can reflect the damage degree of the material in the loading process. After nonlinear finite element analysis, the comparison of the numerical results with experimental ones show that the numerical model is reliable. The numerical model can be used to obtain the damage development process of the wall materials due to the material constitutive model considering the influence of the damage.2. The filling block, lattice rib and outer frame there parts play a role in turn in the loading process of wall. Numerical calculated material damage factors of filling block, lattice rib and outer frame are used to obtain the damage index of each part according to the specific gravity of the material damage factors. Component damage index can reflect the working mechanism of different parts in the wall.3. The contribution of each component in the loading process of multi-ribbed composite wall is different. The change of shear force during the loading process of wall is studied. The shear sharing ratio of different parts is taken as the weight factor, and the global damage index is obtained by the weighted combination of the component damage index. Global damage index is a comprehensive evaluation of the damage degree of the wall.4. The finite element models of the wall with the key parameter variation are established to study the influence of shear span ratio and axial compression ratio on the damage of the wall and verify the applicability of the proposed multi-ribbed composite wall damage model under different conditions. Finally, the damage index of different damage grades of multi-ribbed composite wall is concluded, which provides a reference for the seismic design based on damage performance.Component damage index is constructed by material damage factor and the global damage index is calculated by the component damage. This damage model can not only show that the material damage cause the deterioration of the performance of the wall, but also can reflect the damage process of the different parts of the wall.