10.26731/1813-9108.2018.2(58).8-18
The high level of wear of the fixed production assets of engineering constructions and metalwork as well as the operation of objects in beyond design basis terms could cause the damage emergency due to the great amount of damage and loss. The intensive accumulation of damageability and the long terms of operation with fatigue cracks are characteristic of subcrane beams of bridge cranes of the heavy operating modes under the conditions of cyclic loading. The article presents the results of numerical researches of the bearing ability of a subcrane beam in regular and emergency operation on the basis of the final element analysis of the stress-strain state. By the results of the calculations, the distributions of tension intensity of stresses arising at the upper zone of a subcrane beam wall along its length at various values of eccentricity of the loading caused by the rail displacement from a vertical axis of the beam section are obtained. It has been found that the increase of the loading eccentricity could lead to the accelerated development of the emergency situation with the sharp decrease of the load-bearing capacity of the subcrane beam. The consistent patterns of the stress-strain state of the beam wall due to a number of factors in normal and in emergency operation have been determined. It has been shown that the crack could lead to the redistribution of stresses in the subcrane beam wall. The dependence of a crack growth rate on the size of eccentricity of beam loading has been considered and intensity of stresses arising at the top of the crack. Based on the traditional methods of fracture mechanics, the analysis of the residual resource of subcrane beams with operational defects has been made.
1. Moskvichev V. V., Chaban E. A. Issledovanie napryazhenno-deformirovannogo sostoyaniya podkranovykh balok v shtatnykh rezhimakh ekspluatatsii [Investigation of the stress-strain state of the crane girders in the regular operation modes] Zhurnal SFU. Tekhnika i tekhnologii [SibFU Journal. Engineering & Technologies], 2016, No. 4, pp. 572–584.
2. Moskvichev V. V., Chaban E. A. Issledovanie napryazhenno-deformirovannogo sostoyaniya podkranovykh balok v usloviyakh avariinykh situatsii [Investigation of the stress-strain state of crane beams in emergency situations]. Problemy bezopasnosti i chrezvychainykh situatsii [Safety and Emergencies Problems], 2016, No. 5, pp. 3–15.
3. Saburov V. F. Osobennosti sovmestnoi raboty kranovykh rel'sov i podkranovykh balok v podkranovykh putyakh proizvodstvennykh zdanii [Features of joint operation of crane rails and crane girders in crane tracks of industrial buildings]. Izv. vuzov. Stroitel'stvo [News of higher educational institutions. Construction], 1995, No. 12, pp. 8–13.
4. Sergeev A. V., Shafrai S. D. Vliyanie osobennostei napryazhennogo sostoyaniya v podkranovykh balkakh na ikh prochnost' i vynoslivost' [Influence of the stress state features in crane beams on their strength and endurance]. Izv. vuzov. Stroitel'stvo [News of higher educational institutions. Construction], 1997, No. 7, pp. 9–12.
5. Artyukhov V. N., Shcherbakov E. A., Goritskii V. M., Shneiderov G. R. O sostoyanii podkranovykh konstruktsii korpusa konvertornogo proizvodstva OAO «Severostal'» [On the state of the crane constructions of the case of converter production of OJSC Severostal]. Promyshlennoe i grazhdanskoe stroitel'stvo [Industrial and civil engineering], 2001, No. 6, pp. 31–34.
6. Vasyuta B. N. Nekotorye osobennosti razvitiya ustalostnykh treshchin v verkhnei zone stenki svarnykh podkranovykh balok [Some features of the development of fatigue cracks in the upper zone of the wall of welded crane girders]. Izv. vuzov. Stroitel'stvo [News of higher educational institutions. Construction], 2003, No. 10, pp. 4‑13.
7. Zakrevskii M. P., Moskvichev V. V., Kotel'nikov V. S., Chernyaev A. P., Chaban E. A. Analiz predel'nykh sostoyanii podkranovykh balok [Analysis of the limiting states of crane girders]. Bezopasnost' truda v promyshlennosti [Occupational Safety in Industry], 2004, No. 3, pp. 31–33.
8. Krylov I. I., Tarasevich V. V. Zhivuchest' ekspluatiruemykh svarnykh podkranovykh balok s ustalostnymi povrezhdeniyami [Vitality of exploited welded crane beams with fatigue damage]. Izv. vuzov. Stroitel'stvo [News of higher educational institutions. Construction], 1998, No. 2, pp. 17‑25.
9. Kotsan'da S. Ustalostnoe razrushenie metallov [Fatigue destruction of metals]. Moscow: Metallurgiya Publ., 1976, 456 p.
10. Mekhanika razrusheniya i prochnost' materialov: Sprav. posobie v 4 t. T. 4. Ustalost' i tsiklicheskaya treshchinostoikost' konstruktsionnykh materialov [Mechanics of destruction and strength of materials: Reference book in 4 vol. Vol. 4. Fatigue and cyclic crack resistance of structural materials]. Kiev: Nauk. Dumka Publ., 1990, 679 p.
11. Moskvichev V. V., Makhutov N. A., Chernyaev A. P. et al. Treshchinostoikost' i mekhanicheskie svoistva konstruktsionnykh materialov tekhnicheskikh system [Crack resistance and mechanical properties of structural materials of technical systems]. Novosibirsk: Nauka Publ., 2002, 334 p.
12. Fracture mechanics and strength of materials: reference. manual Vol. 4. Fatigue and cyclic fracture toughness of structural materials. Kyiv: Sciences. Dumka, 1990. 679 p.
13. Troshchenko V. T., Pokrovskii V. V., Prokopenko A. V. Treshchinostoikost' metallov pri tsiklicheskom nagruzhenii [Crack resistance of metals under cyclic loading]. Kiev: Nauk. Dumka Publ., 1987, 256 p.
14. Makhutov N. A. Deformatsionnye kriterii razrusheniya i raschet elementov konstruktsii na prochnost' [Deformation criteria of destruction and calculation of structural elements for strength]. Moscow: Mashinostroenie Publ., 1981, 272 p.
15. Sklyadnev A. I., Serdyuk V. V. Ustalostnaya dolgovechnost' i mera povrezhdaemosti verkhnei zony stenki svarnykh podkranovykh balok [Fatigue durability and the measure of damageability of the upper zone of the wall of welded crane girders]. Bezopasnost' truda v promyshlennosti [Occupational Safety in Industry], 2004. No. 11, pp. 34–36.
16. Mekhanika katastrof. Opredelenie kharakteristik treshchinostoikosti konstruktsionnykh materialov. Metodicheskie rekomendatsii. Mezhdunarodnyi institut bezopasnosti slozhnykh tekhnicheskikh sistem [Mechanics of disasters. Determination of the characteristics of crack resistance of structural materials. Methodical recommendations. International Institute for the Safety of Complex Technical Systems]. MIB STS Publ., 1995, 360 p.