| As the main form of transporting aggregate,the coal transporting gallery has been widelyused in coal mining,coal preparation plants,thermal power plants and other industrial fields.Due to the long-term mechanical vibration of gallery during operation,the vibration response of gallery is too large.Therefore,this paper takes the coal transportation gallery of Ningtiaota coal mine as the research object,using the structural dynamic theory calculation and the numerical analysis software to get the structural dynamic response of gallery,comparing the actual monitoring situation of the Ningtiaota gallery,and judging the rationality of the calculation results,the concrete work and the main conclusions are as follows:1.The structure and characteristics of the structure of the coal transporting gallery are introduced.According to the structure characteristics of gallery,gallery is regarded as a simple supported beam.The coal load is regarded as a multi point moving simple harmonic load.By using the basic theory of structural dynamics Euler-Bernoulli beam,the displacement response of a simple beam under the action of simple harmonic force is obtained.The vertical vibration response curves of three typical span(30m,33m,39m)of the Ningtiaota gallery are calculated by using MAPLE software.The influence of the parameters of the beam body on the dynamic response of the structure is analyzed.The smaller the mass of the beam is,the smaller the dynamic response of the structure,the larger the stiffness of the beam and the smaller the dynamic response of the structure.Therefore,in the structural design of the gallery,the dynamic response of the structure can be reduced by reducing the self weight of the beam structure or strengthening the stiffness of the beam structure.2.By monitoring the dynamic response of Ningtiaota gallery,the dynamic response value of the structure under different conditions of gallery can be obtained.Select the corresponding vibration control standard,and the measured data of the Ningtiaota gallery are compared and analyzed to judge the safety during the operation of the gallery.3.Using the numerical analysis software,the modal analysis,time history analysis and frequency domain analysis are used to analyze the structure of the coal transporting gallery in Ningtiaota coal mine,so as to obtain the dynamic response law of the coal transporting gallery.In modal analysis,the first mode shape of trestle structure is horizontal vibration,the second mode shape is vertical bending,and the third mode shape is transverse torsion.The law of influencing natural vibration of trestle structure is analyzed and explored.In the time-history analysis,the maximum values of vertical displacement and vertical acceleration of trestle structures with three spans are obtained.In the frequency domain analysis,it is obtained that the trestle structure will have obvious resonance phenomenon in the low frequency section during the process of belt conveyor shutdown to normal working state.4.The analytical solution of gallery structure calculation,numerical solution and the comparison and analysis of the measured values in the field show that both theoretical and simulated values are less than the measured values,but the difference is small.It is proved that the applicability of theoretical calculation and numerical calculation has a certain guiding meaning for practical engineering design. |
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