Evaluating the strength of a beam-type electric switch mechanism housing
https://doi.org/10.21683/1729-2646-2022-22-4-3-7
Abstract
Aim. Choice of method and its validation for the purpose of confirming the feasibility of safe operation of a switch mechanism housing submitted to rolling stock axle loads of 30 tf.
Method. As of today, there are neither regulations regarding the strength parameters of load-carrying elements of electric switch mechanisms, nor verification procedures. Given the above, when evaluating the strength of electric switch mechanism housing, the authors used the method used for the purpose of evaluating the strength of load-carrying elements of locomotives per GOST R 55513-2013. That method has a long history of application as part of calculation and testing of motive power and has shown good results. According to the method, strength is evaluated by comparing the safety factor of fatigue strength n with the allowed value for steel structures [n] = 2.0.
Result. The activities resulted in the validation of the proposed method of strength estimation by the criterion of fatigue strength. The value of fatigue endurance of electric switch mechanism housing was estimated based on the results of fatigue benchmark tests of three items. Each was stressed by stepping up the amplitude of the applied force after the base number of cycles had been reached. At the first stage, the loading was equivalent to the operational value. After the base number of functions had been reached for each item, the following step was initiated. The tests continued until cracks have been found. In the process of testing, the amplitude of stress was recorded at each level of loading. For the purpose of identifying the fatigue strength characteristics, the reduced fatigue strength of the switch mechanism housing was calculated under the hypothesis of linear addition of fatigue damage subject to the condition of deterministic loading and subsequent processing of the findings using statistical methods. The value of fatigue limit has been obtained for the housing of a tie-type electric switch mechanism equal to 48.4 MPa. The safety factor of fatigue strength was found to be equal to 2.86, which is above the minimal allowed value.
Conclusion. It has been shown that the housing of a tie-type electric switch mechanism has a sufficient strength as regards the operational static and dynamic loads. Its safe operation when exposed to axle loads of 30 tf has also been confirmed.
About the Authors
E. S. OganianRussian Federation
Eduard S. Oganian, Doctor of Engineering, Head Researcher
410 Oktyabsrskoy revolutsii st., 140402, Kolomna, Moscow Oblast
S. V. Chunin
Russian Federation
Sergey V. Chunin, Head of Laboratory
410 Oktyabsrskoy revolutsii st., 140402, Kolomna, Moscow Oblast
D. M. Fazliakhmetov
Russian Federation
Damir M. Fazliakhmetov, Lead Engineer
410 Oktyabsrskoy revolutsii st., 140402, Kolomna, Moscow Oblast
E. V. Muravlev
Russian Federation
Yevgeny E. Muravlev, Lead Engineer
410 Oktyabsrskoy revolutsii st., 140402, Kolomna, Moscow Oblast
O. A. Lobachev
Russian Federation
Oleg A. Lovachev, Lead Engineer
410 Oktyabsrskoy revolutsii st., 140402, Kolomna, Moscow Oblast
References
1. GOST R 55513-2013. Locomotives. Requirements for strength and dynamic properties. Moscow: Standartinform; 2014. (in Russ.)
2. Savoskin A.N., Burchak G.P., Matveevichev A.N. et al. Savoskin A.N., editor. [Strength and reliability of railway rolling stock]. Moscow: Mashinostroenie; 1990. (in Russ.)
3. Stepnov M.N. [Statistical methods for processing the results of mechanical tests]. Moscow: Mashinostroenie; 1985. (in Russ.)
4. Kogaev V.P. [Time-variable strength calculation]. Moscow: Mashinostroenie; 1993. (in Russ.)
Review
For citations:
Oganian E.S., Chunin S.V., Fazliakhmetov D.M., Muravlev E.V., Lobachev O.A. Evaluating the strength of a beam-type electric switch mechanism housing. Dependability. 2022;22(4):3-7. (In Russ.) https://doi.org/10.21683/1729-2646-2022-22-4-3-7