Structure Design Optimization And Vibration Analysis Of Foamed Asphalt Mixer

As a new type of binder,foamed asphalt attracts attention from the road community for its outstanding advantages like energy-saving,environmental protection and economy.The preparation of high-quality foamed asphalt mixture is a prerequisite for ensuring road quality and performance.Foamed asphalt mixer is the key equipment for implementing foamed asphalt construction technology.This paper aims to develop a foamed asphalt mixer with the goal of high efficiency mixing of homogeneous foamed asphalt mixture.Mixing foamed asphalt mixture involves three mixing mechanisms: convection,shearing,and diffusion.There is a strong collision,slip,and friction between particles.In order to obtain an efficient and homogeneous foamed asphalt mixture and to reveal the flow characteristics and the motion law of the aggregate in the mixing movement,the discrete element method was used to construct the Hertz-Mindlin contact model for the aggregate movement,which is based on the analysis of the foamed asphalt mixture mixing process.With the goal of mixing homogeneity and mixing efficiency of the mixture,the key design parameters of the mixer are designed and optimized.Based on this,the vibration response of the mixer under unbalanced excitation force was analyzed to ensure the smooth operation of the mixer and the homogenous foamed asphalt mixture was mixed with high efficiency.The specific research content is as follows:1)The mixing rules of foamed asphalt mixture were revealed and the key parameters of the mixer were optimized.Based on the mixing process of foamed asphalt mixture,a movement model of the aggregate was established to analyze the flow characteristics and motion law of aggregates with different particle sizes.With the goal of mixing homogeneity and mixing efficiency of the mixture,the stirring arm’s phase angle,blade installation angle,blade shape,number of blades,and agitator shaft speed were redesigned.2)Optimization design of foamed asphalt mixture mixer rack was implemented.After the topology optimization,the new shape of the rack is obtained.The specific size of the structure was obtained by using response surface optimization method.A reliable,lightweight and beautiful design of the rack is achieved.3)Vibration analysis of foamed asphalt mixture mixer is performed.The self excited vibration and forced vibration of the mixing parts are analyzed separately.Based on the principle of dynamic balance,the harmonic load was obtained during the operation of the stirring component.In order to achieve the safe operation of the mixer,the influence of harmonic load on the mixer drum and mixing rack was analyzed.Thesis provides theoretical support for the development of foamed asphalt mixture mixer.