Research On Impact Damage Characteristics Of Coal Falling Area In Middle Groove Of Scraper Conveyor

China is rich in coal resources,which provides the inexhaustible power for economic development.The steady development of economy puts forward higher requirements for coal development.How to improve coal mining efficiency under the premise of economy and environmental protection has become a new challenge.Scraper conveyor is one of the important mining equipment,and extending the service life of it is an effective method.Impact damage is one of the main failure modes of scraper conveying.Therefore,the study of impact damage is very necessary.The basic law of impact damage is obtained through research,which provides a theoretical basis for reducing the impact damage of the scraper conveyor.This paper research from both theoretical and simulation aspects,the content are as follows:On the basis of understanding the composition of the scraper conveyor,this paper firstly analyzes and summarizes the basic theory of impact damage at home and abroad,the mechanism of impact damage of the scraper conveyor and the virtual prototype technology,and clarifies that the research of impact damage of middle groove is of great significance to reduce the damage of it.Secondly,based on the theory of impact energy on the middle groove impact damage,taking the coal falling area of the middle groove of the scraper conveyor as the research object,the impact damage formula is derived,and the impact energy conversion rate is solved by Ansys explicit dynamics.The rate is39.6%.This provides a theoretical basis for subsequent impact damage research.In order to fully understand the impact damage process,a solid model of scraper conveyor was established by using Solid Works software.Under the action of single factor and compound factor,the change laws of impact damage depth and normal cumulative contact energy under different laying angles(roll angle,front angle),chain spacing,particle size of coal bulk materials were explored respectively.The data obtained are analyzed by matrix numerical analysis,and the impact damage depth and normal cumulative contact energy are taken as evaluation indexes to obtain the relative optimal combination and the weight of each factor.The results show that: the particle size > the chain spacing > the roll angle > the front angle,the relative optimal combination scheme is the front Angle 5°,the front angle 10°,the chain spacing is medium double chain,the particle size is 0.5 times the base particle size.In order to further verify the authenticity,the impact damage depth and normal cumulative contact energy of scraper conveyor under the relative optimal combination condition are obtained,and the relative optimal combination in the impact process is verified by simulation.The stress and strain nephogram of the middle groove is further obtained by Ansys analysis,and it is concluded that the middle position of the middle groove bears the greatest stress,while the two sides bear less stress.In this paper,the impact damage characteristics of the middle groove under single factor and compound factor working conditions are explored,and a relatively systematic research system is formed.The results also show that the basic law of impact damage has a certain guiding effect on the improvement of the scraper conveyor and the production working conditions.