Study On Slab Rolling Mill Vibration Characteristic And Roller Wearing Evaluation

The plate products are widely used in many fields of ship， bridge， container，especially raw material used as a production aircraft carriers， large ships and large diameterlongitudinal welded pipe， which relates to national security and energy security. It has animportant strategic significance to improve the plate production efficiency and product quality.In thick plate rolling，the large-scale，high-speed，continuous and higher automated are themain stream. The vibration is a common and urgent problem，which is a worldwide technicalproblems plagued the major iron and steel enterprises. Because the vibration phenomenon notonly reduces the mechanical properties of the mill， decreases its service life， increases thefrequency of replacement parts， so that production costs rise， but also reduces the precisionof rolling mill， seriously affecting the quality of the products. Severe vibration even causes alot of waste， broken belt， rolling mill shutdowns or does some damage to equipment，which is a serious threat to safe production and cause huge economic losses.Based on the slab heating thermal stress analysis and rolling force analysis， the modelof plate rolling is established in this paper， which is using study on the dynamic vibrationcharacteristics of plate mill. The support vector regression identification model is establishedin accordance with fault phenomenon， which is used in fault diagnosis for rolling mill. Thismodel improves the operation safety level， reduces downtime， repair time， and improvesthe overall technical level of the plate， which is great significance to enhance thecompetitiveness of the industry. The main content of the paper are as follows：Stress analysis of slab heating. A full size slab heating three-dimensional finite elementsimulation model is established in this chapter，which simulates the slab heating process withthe modern CAE software. According to the actual heating process parameters， the thermalstress distribution law is obtained. The heating parameters include heating temperature， heating rate， heating time.Rolling force analysis based on heating stress distribution. The three-dimensional finiteelement rolling model is established based on the slab heating temperature field and heatingstress field. According to the actual rolling parameters， the multi passes of rolling processare analyzed. The rolling force distributions are obtained. The main influencing factorsinclude roll diameter， compression ratio， friction coefficient， and so on.Rolling vibration analysis based on dynamic rolling force. Using dynamics theory andmethod， the vertical vibration model and mathematical model are established in this chapterbased on the thermal stress analysis and the rolling force analysis， Through analysis andsimulation of system dynamics model， the vibration characteristics is obtained. Research ondifferent damping conditions， each component of the frequency response curves areanalyzed. The vibration characteristics of the mill frame and working roller， and the typicalfault vibration characteristics are gained.Roller wearing evaluation analysis based on Support Vector Machine. On the basis ofrelevant theoretical knowledge of Support Vector Regression， Comparative analysis is usingin several classification methods of analysis. For wear phenomenon for finite sample， theidentification model is established based on support vector regression. Through the simulationanalysis， the identification model of support vector regression is verified to have the betterfitting precision， the good identification accuracy and efficiency， which can provide theequipment management personnel with comprehensive and accurate information to ensuresafe production.Wear evaluation experiment analysis. The rolling mill vibration test scheme is designedin this chapter， which uses high precision rolling vibration test system. The experiment ofvibration measurement of roller and framework is finished in the condition of different speedswithout load， which can gain the mill system unload vibration characteristics; the influenceexperiment of compression ratio on the framework and roller system is finished， which cangain the vibration characteristics of different compression ratio; the effect experiment ofroller wear fault on the framework and roll roller is finished， which can gain the vibrationcharacteristics of roller wear fault;Using DASP V10. analysis software， the data is analyzed by online acquisition andoff-line， using time domain analysis， frequency domain analysis， the spectral analysis，the cross spectral analysis， probability density analysis theory and method. Through thecalculation and analysis of vibration signal， the real law of vibration of four rollers mill inthe actual operating conditions are gained， which is used in roller wear evaluation analysis， this experiment verifies the identification model based on support vector regression has betterprecision， which realizes the accurate wear evaluation analysis resulted by rolling vibration.