| Coal transporting trestle, as a major industrial structures of supporting rubber belt conveyer, is widely used in coal, power and other industrial production. In recent years, due to the need of the production process, coal transporting trestle has become the large span structure more. It is most use of steel in the form. Due to their small stiffness of steel structure and large span, coal transporting trestle structures will produce vibration under dynamic loads of machinery and equipment. Practice shows that, at present, the coal transporting trestle vibration problems are more serious. Especially in the transitional stage of startup or braking, coal transporting trestle will produce resonance phenomenon, and the vibration of coal transporting trestle has become an urgent problem need to study and solve.This paper studied the approach of the use of suspension tuned mass damper(referred to as TMD) system to reduce vertical vibration of the coal transporting trestle, based on a instance of under-suspension grid structure. The main work of this paper is as follows:(1)By searching documents, the main structure and structural characteristics of coal transporting trestle, the research status of coal transporting trestle vibration problems and TMD for vibration control was generalized.(2) Based on a instance of under-suspension grid structure, in SAP2000 finite element analysis software, three-dimensional structural model was built. And then, through modal analysis, harmonic analysis and time history analysis load in harmonic of the structural, the dynamic characteristics and vibration response of the structure was analyzed.(3) Based on the multiple tuned mass dampers(referred to as MTMD)model of frequency linear distribution and Den Hartog parameter optimization method, the influence of parameters on vibration control effect, such as the number of TMD, total mass ratio, damping ratio, bandwidth and center frequency ratio of MTMD was analyzed.(4) According to the model of the structure, TMD stiffness and damping parameters was calculated, and the position, the mass ratio, quantity of the TMD was determined. On the basis of the original structure model, the structure-TMD model was established. Harmonic response analysis performed to calculate the vibration response, and the vibration response of the original structure were compared to determine the damping effect of TMD. Damping effect of the two parameter optimization method was compared to determine parameter optimization method used.(5) Dynamic characteristics were analyzed about the structure-TMD model based on the Den Hartog parameter optimization method used and compared with the original dynamic characteristics. Changes in the dynamic characteristics of the structure with TMD were analyzed to research TMD damping mechanism. Through harmonic analysis and time history analysis load in harmonic and time history analysis of under seismic of the structural, vibration control effect of TMD was researched. The results show that, TMD vibration control for coal transporting trestle has a good effect. |
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