No abstract

No abstract

No abstract

One of the advanced ways of provision of functional properties of interference fit joints is to control contact interaction between mating parts, particularly by assembling with application of anaerobic materials polymerizing in contact area. The main advantage of using anaerobic materials is that this technology allows us to harden different parts of the joints selectively. The purpose of the work is to study the possibility of rational provision of functional properties of interference fit joints by selective hardening in case of assembling with the use of anaerobic materials. Modelling of bearing strength of interference fit joint is carried out according to finite element method, with theory of contact interaction between mating surfaces being used. The results of experimental research are given. Anaerobic material is used as a material for hardening of joints. It was discovered that exploitation load in form of torque or axial force is distributed along the length of interference fit joint rather nonuniformly. To decrease expenses, it is necessary to harden those areas of joint which are located by the side of load application. The way of assembling of interference fit joints by pressing with selective use of hardening material is proposed. The technique of reliable identification of the necessity and the moment to apply anaerobic material while assembling parts was developed. As a result, functional properties of pressure joints are reached the most rational way.

Stress concentration in thread roots and nonuniform load distribution along thread turn are the major disadvantages of bolted joints. Under changing cyclic loads on areas of high stress concentration crack formation and destruction of parts occur. In addition, the fretting corrosion processes activate in the areas of contact between thread turns. The purpose of the work is to increase rupture strength of bolted joints under the action of cyclic forces by decreasing stress concentration and reducing movements in contact zone of mating parts in case of assembly with implementation of anaerobic materials. Modelling of bearing strength of bolted joints is conducted according to finite element method, with theory of contact interaction between mating surfaces being used. The results of experimental research are given. Anaerobic materials which polymerize in area of thread contact of parts are used. It was established that assembly with implementation of anaerobic material allows unloading of thread turns because the part of external load is received by elastic layers of the polymerized anaerobic material. In this case the level and the concentration of stress in thread roots reduce, relative movements are decreased, the joint becomes more rigid and its cyclic robustness grows.