Experimental And Numerical Simulation Technique And It's Application In Bar Damage Detection

Structural damage detection is one of the key topics in civil engineering. There is urgent demand in engineering practice. Straight bar is both one kind of representative structure and basic element of complex structure. Most of the structural damages appear in bars or joints. Damage detection method in straight bar is studied by modal test, theory analysis and numerical simulation. It can be concluded that:(1) Systemic modal test was conducted on three straight steel bars. Music tone law method and frequency ratio method were proved to be effective for damage detection of this kind of specimens.(2) Torsion spring model and general step beam model were used to simulate the steel model. Analytic solutions and numerical solution model of ANSYS were compared with the experimental results subjected to the two kinds of working condition. The results show that the analytical solution and test results do not agree well, but can be used to judge validity of numerical simulation results by qualitative. A comparison of experimental results with the ANSYS model simulation show good agreement, which can be used as a benchmark for the structural health diagnosis to identificate the damage situation of structure.(3) Symmetrical signal method ,Musical tone law method and Frequency ratio method were proved to effective for symmetrical structure and for unsymmetrical structure, modal parameters derived from finite element method .can be regarded as the baseline for structures without damage; Damage can be detected by incorporating musical tone law method and frequency ratio method.