Damage Index Evaluation Method For Seismic Performance Of Structural Members

In order to find the best evaluation indicators of structural members’seismic performance, first, various seismic evaluation methods of structural members were introduced, comparing these methods, advantages and disadvantages of them are gotten; then, experiment research that using one of the most optimal evaluation method of structural members seismic performance were conducted; At last, the optimal evaluation index of structural members’seismic performance can be gotten through research.The common research methods of structural members’seismic performance are combination of theory and experiment at present. Theory researches are based on structural dynamics methods, such as static elastic-plastic analysis and dynamic elastic-plastic time history analysis etc. But the theoretical analysis methods also need test support. Experiment research is also relatively mature. There are pseudo-static test, pseudo-dynamic test and shaking table test. Pseudo-static test due to its implementation is more convenient, concept is clear, and can be get structures and members’seismic indicators exactly, thus it become the common test method currently. Pseudo-dynamic test and shaking table test due to its high cost of implementation, and there are large differences between them and actual earthquake, these two kinds of testing scheme are rarely used at present.Various mechanical performance index can be obtained through pseudo-static test. The load-displacement curve, named hysteresis curve can be obtained directly. Then bearing capacity, ductility, stiffness, and energy dissipation can be gotten through hysteresis curve. Damage index can be calculated with the above index. By comparing these performance indicators of structural members, damage index which based on displacement and energy accumulation is relatively better evaluation index of seismic performance. In order to prove the advantage of damage index in evaluating structural members’seismic performance, the test data of related literatures were collected and analyzed. The results showed that the damage index has its unique advantage in evaluating seismic performance of structural members.Because the influence of damage on structural members’stiffness, with concrete composite slabs with precast ribbed bottom as an example, a hysteresis rules that based on members’damage can be put forward. Then restoring force model that based on damage can be established, and the influence of damage to stiffness was analyzed. According to the analysis of members’damage and deformation, approximate linear relationship can be found between damage and deformation. Then a structural design method that based on damage model can be proposed. The validity of the design method can be proved through example. The results are reliable enough to be referenced by engineers and designers.