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

Abstract

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.