Model Updating Method And Experimental Study Using Additional Virtual Masses

In recent decades, damage identification algorithms have emerged, but due to the large-scale and complex of the civil engineering structures, these damage identification algorithm is very limited, so the emergence of new damage identification algorithm is very important for the structural health monitoring, present damage identification technology in civil engineering applications is not a lot. So this article proposes the damage identification method using additional virtual masses. The following is the research contents of this paper.(1)It mainly introduces the basic theory of the model updating method using additional masses. Virtual Distortion Method (VDM) is a fast re-analysis method. It can directly identify the damage of the structure not needing to re-modeling the original structure. The damage identification method using additional masses comes from the Virtual Distortion Method, and using the basic principle of the Virtual Distortion Method, it deducts the formula of damage identification using additional virtual masses method.(2)It verities the feasibility of the model updating method using additional virtual masses using the cantilever beam experiment. Using Piezo electric sensor, modal force hammer and NI signal acquisition instrument were used in the test. Firstly, use the modal force hammer to excite and measure it and measure the corresponding acceleration. The test data were processed by the means of FFT and exponential window and then through the formula the images of the calculated structural frequency response with additional virtual changes of the quality were got. Considering the sensor quality, the finite element model of the cantilever beam were established by using MATLAB. Use the obtained curve to correct the elastic modulus of the finite element model and the quality of the additional sensor.(3)It verities the feasibility of the damage identification using additional masses. The test data processing and the test process are the same as the cantilever beam test. The calculated structural frequency response with the additional virtual changes also can be got. Cut a bar of the truss and use ANSYS to simulate the damage and the damage can be got by comparing the frequency relationship of the other bars. It was imposed the same incentive for the transient analysis By comparison, it can estimate the damage degree roughly.