Study of residual stress-strain behavior of a load-bearing system of a skid-steer loader under multiple loads according to the ROPS safety standard

Introduction (problem statement and relevance). Ensuring safety of road vehicles is a relevant problem. It is particularly applicable to the road construction machinery. The paper presents an algorithm that allows obtaining the most accurate results of calculations according to the procedure described in GOST R ISO 3471 (ROPS): Earth-moving machinery. Roll-over protective structures. Technical requirements and laboratory tests.
The purpose of the study is to investigate the stress-strain behavior (SSB) of a structure of a utility platform taking into account residual stresses, strains and relaxation of the structure under multiple loads according to the roll-over safety requirements for earth-moving machinery.
Methodology and research methods. The paper presents a skid-steer loader cabin model created in a fi nite element analysis program to perform the strength calculations. The comparative assessment was performed based on the results of a full-scale experiment carried out on a real structure and of virtual simulations. The research object is a skid-steer loader cabin. The research subject is the design methods for vehicle load-bearing structures and their use taking into account operating conditions.
Scientific novelty and results. An algorithm has been created which takes into account residual stresses, strains and relaxation of the structure for further loading and allowing reduction of a displacement calculation error for a utility platform from 84.5 to 4.5%. The internal energy reached under vertical load is 426% higher, while for the longitudinal load case it is 14.6% higher, than for the option not taking into account residual stresses and strains.
Practical signifi cance. The proposed algorithm allows considering the requirements of GOST R ISO 3471 regarding prevention of structure readjustment or repair between loadings, which is an actual operating mode.

1. Goncharov R.B., Zuzov V.N. [Truck cabs improvement at the design stage with the purpose to ensure passive safety requirements in case of impact and minimum weight]. Trudy NAMI, 2019, no. 3 (278), pp. 28–37. (In Russian)

2. Shaban B.A., Zuzov V.N. [Analysis of the impact of cab design factors on the passive safety of trucks in case of impact on the front pillars]. Nauka i obrazovanie: nauchnoe izdanie MGTU im. N.E. Baumana, 2013, no. 11, pp. 95–106. (In Russian)

3. Khusainov A.Sh., Kuz’min Yu.A. [Passive vehicle safety: Textbook for students of directions 190100.62 “Ground transport and technological complexes” in the profi le – Automobile and tractor building and “Ground transport and technological means” in the specialization “Automobiles and tractors”]. Ulyanovsk, UlGTU Publ., 2011. 92 p. (In Russian)

4. Zuzov V.N., Sulegin D.A. [An investigation of the eff ect on the energy intensity of the main power elements of the car body in the side impact zone]. Vestnik YuUrGU. Seriya: Mashinostroenie, 2020, vol. 20, no. 4, pp. 20–34. (In Russian)

5. Goncharov R.B., Zuzov V.N. [Features of the search for optimal parameters of the amplifi ers of the rear part of the cab of a truck based on parametric and topological optimization in order to ensure the requirements for passive safety according to international rules and obtain its minimum mass]. Trudy NGTU im. R.E. Alekseeva, 2019, no. 2 (125), pp. 163–170. (In Russian)

6. Vdovin D.S. [Topology optimization in rops-safe design process of operator cabin for forestry, agricultural and construction machinery]. Izvestiya MGTU MAMI, 2018, no. 4 (38), pp. 21–29. (In Russian)

7. Goncharov R.B, Zuzov V.N. [Problems of fi nding optimal design parameters of a car bumper under impact from the standpoint of passive safety]. Trudy NGTU im. R.E. Alekseeva, 2018, no. 3 (122), pp. 130–136. (In Russian)

8. Goncharov R.B., Zuzov V.N. [Problems of fi nding optimal solutions to ensure the passive safety of truck cabs with a minimum weight]. Izvestiya MGTU MAMI, 2018, no. 4 (38), pp. 92–102. (In Russian)

9. Gore P., Barjibhe R.B. Design of protective structure of operator cabin against falling object (FOPS). International Journal of Latest Trends in Engineering and Technology (IJLTET), 2014, vol. 3, pp. 228–236.

10. Karliński J., Rusiński E., Smolnicki T. Protective structures for construction and mining machine operators. Automation in Construction, 2008, vol. 17, pp. 232–244.

11. Clark B. The behavior of rollover protective structures subjected to static and dynamic loading conditions. PhD dissertation. School of Civil Engineering Queensland University of Technology, 2005.

12. [GOST R ISO 3471-2009. Earth-moving machinery. Roll-over protective structures. Technical requirements and laboratory tests]. Moscow, Standartinform Publ., 2011. 32 p. (In Russian)

13. Shaban B.A., Zuzov V.N. [Features of modeling frame elements of car bodies and cabs in the study of passive safety]. Nauka i obrazovanie: nauchnoe izdanie MGTU im. N.E. Baumana, 2012, no. 11. DOI: 10.7463/1112.0486675. (In Russian)

14. Shaban B.A., Zuzov V.N. [Features of building fi nite element models of cabins for the study of passive safety on impact in accordance with UN Regulations no. 29]. Nauka i obrazovanie: nauchnoe izdanie MGTU im. N.E. Baumana, 2013, no. 03. DOI: 10.7463/0313. 0542301.

15. Belytschko T., Lin J., Tsay C.S. Explicit algorithms for nonlinear dynamics of shells. Comput. Methods Appl. Mech. Eng., 1984, vol. 42, iss. 2, pp. 225–251.

16. Doğan U.Ç. Eff ect of strain history on simulation of crashworthiness of a vehicle. Middle East Technical University, 2009.