Calculation Of Friction And Wear And Study And Development Of Expert System

Friction and wear both are important components of the science of Tribology.Friction is a force that opposes the relative motion of two surfaces in contact,and in the presence of friction,some energy is always lost.And the wear can be found between surfaces during frictional contact and causes the material surfaces to gradually degrade.Friction is the prerequisite and basic of the wear,while the wear is the consequence and accumulation of the friction.According to the statistics,about 30%to 50%of the energy in the world is consumed by the friction and wear of mechanical parts,and about 60%to 80%of the material failure and damage are caused by wear.Therefore,researches on friction and wear become increasingly valued by experts and scholars at home and abroad.Study on the friction and wear are currently focused on experimental measurements and qualitative analysis.However,quantitative calculation and analysis are rare,and the systematic and applicable calculation and analysis software of the friction and wear are still scarce.According to those mentioned above,this subject is based on the project of National Nature Science Foundation of China——"Calculation Tribology"(item number:515751907),making several relative researches on the friction and wear calculation,and develops an expert system on calculation tribology which can be available to scientific researchers and Engineering Technicians.Its main contents are as follows:(1)According to the regular law of the movement and force characteristics of the gear pair in the meshing process,we establish the calculation model of the involute spur gear wear.And the relationships between the pressure angle at the contact point of the tooth profile and its relative slip coefficient,mutual friction distance,wear rate and wear amount are analyzed in detail with numerical calculation methods.(2)According to the relevant characteristics of the calculation tribology expert system and its various functions that need to be realized,the key technologies and related theories used in the development of the system are elaborated in detail in this paper,and the development tools of the system(Visual Basic 6.0)and the background database(SQL Server 2008)are determined through the comparative analysis.(3)Adopting the friction and wear calculation method proved practical by most scientists and appropriate programming methods,the general theory of the friction and wear calculation is transformed into available calculation program and establishes the friction calculation module,wear calculation module,and common mechanical component wear calculation module,and common mechanical component wear calculation module of the expert system.(4)A large number of data parameters related to friction and wear calculations and other related knowledge are collected and organized in this paper,and corresponding database management system used to offer assistance in the use of friction calculation modules and wear calculation modules enhances the practicality of this expert system.(5)Taking full account of user's needs,and based on the establishment of a stand-alone calculation tribology expert system,an online version of the friction and wear calculation program is established through the use of Internet programming technology and the network teaching platform(mechanical design network)independently developed by this group.The module is not only convenient for users to use in various channels,but also facilitates the promotion of the system.(6)The calculation methods and principles of the sliding friction coefficient are described in this paper,and a more practical calculation formula is verified from different angles(loads,materials,surface topography and test equipment)with experimental methods.