| The safety situation of hazardous materials transportation is still grim in China.According to statistics,77% accidents of hazardous materials occur during road transportation,and especially the rollover,which is the most representational accident form.Hazardous goods rollover accidents may lead to serious consequences such as leakage,burning,explosion,etc.,result in bad influences such as property damage,environmental pollution,ecological damage,and casualties.The main reasons for restricting the improvement of the safe production level of hazardous goods road transportation in China are the imperfect risk prevention system,the poor ability of active prevention and control of accidents,the blind zone of process monitoring,and the weak coordination ability of key areas.Therefore,it is very important to identify the rollover threshold of dangerous goods transport tank semi-trailers.In this paper,the research status of related aspects are summarized at home and abroad.The discriminating model of tank-type semi-trailer rollover threshold is established by analyzing the related theories of fluid dynamics and steering stability of tank semi-trailers.Finally,through the simulation test,the rollover threshold range of the tank semi-trailer under typical working conditions is obtained.1)On the basis of summarizing the research status at home and abroad,aiming at the deficiency of the current liquid-solid coupling method for tank semi-trailer,a method based on the joint simulation of Trucksim and Fluent to realize two-way liquid-solid coupling is proposed,and the overall framework of the paper is constructed.2)According to the knowledge of fluid mechanics and automobile theory,the tank model(tank shape,number of cabins,boundary conditions)and vehicle dynamics model(suspension system,tire system,aerodynamic system,steering system,braking system)are established separately,the establishment of the tank model needs to balance the contradiction between computer resources and calculation accuracy,and evaluate the quality of the grid;the establishment of the vehicle dynamics model is mainly determined by detailed level of parameters.3)Through the literature reading,accident analysis,questionnaire survey and other means to summarize the tank semi-trailer rollover instability mechanism,under the typical conditions of tank-type semi-trailer tank liquid-solid coupling analysis,the paper analyzes the liquid-fill ratio,liquid type,the influence for liquid sloshing laws in the tank due to the instant change of lateral acceleration and roll angle,and the change law of the centroid offset under different conditions,so as to facilitate the research on the roll stability of the tank semi-trailer.4)Optimaling rollover index to characterize parameters,designing road text according to typical condition,using solid cargo's mass of the van to replace the liquid in the tank body to obtain the movement law of the van and coupling into the tank,realizing the tank body and the van move at the same speed to drive liquid movement in the tank.The two-way coupling is mainly realized by UDF and MATLAB/Simulink.The UDF function can be used for secondary development of Fluent to couple the movement law of the van into the tank.MATLAB/Simulink can couple the sloshing law of the liquid into the van to realize the two-way coupling.Finally,the rollover threshold under typical working conditions is obtained through multiple simulation tests,which provides theoretical guidance for the anti-rollover control strategy. |
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