| Off-highway wide body dump trucks are mostly used in open pit mines and large infrastructure projects with rugged transport roads and serious overloading of materials.These special working conditions,which are different from those of ordinary dump trucks,put forward higher requirements on the performance of off-highway wide body dump trucks.As an important part of the off-highway wide body dump truck,the tipping mechanism is not only the connecting intermediary between the carriage and the frame,but also an important movement joint when the vehicle is unloaded.Its reliability is the key factor for the safe working of dump truck,if the sudden failure during the working process may lead to the vehicle overturning,which will significantly endanger the life and property security of the site workers,so it is very significant and necessary to carry out an in-depth study on the tipping mechanism.This paper takes a certain type of off-highway wide-body dump truck and its tipping mechanism as the object of study,and focuses on the failure of the tipping mechanism that often occurs during the actual use of this dump truck.(1)According to the structural characteristics of the wide body dump truck and the tipping mechanism for dynamic analysis,study the work history of the lifting cylinder and material dumping during the working process of the tipping mechanism,set four typical working conditions of no-load lifting,full-load lifting,off-load lifting and limit lifting,analyze and study the dynamic force situation of the tipping mechanism under each working condition,find out the maximum pressure moment,and define hazard status.(2)Static analysis for off-highway wide-body dump truck tipping mechanism.We simplify the geometric structure of the off-highway wide body dump truck and its rollover mechanism in 3D software,import the simplified structure into the FEM software Hypermesh,pre-process it,and build a FEM model by using a combination of plate and shell units,beam units,solid units and spring units.The boundary conditions are set according to the stress conditions of each operating condition,and the simulation is conducted by Opti Struct solver to analyze the stress and deformation of the off-road wide body dump truck turning mechanism and frame under different working conditions and to define the danger area.(3)The experimental study was carried out for the off-load lifting condition by combining displacement,angle and stress tests.The error between the two is basically less than 15%.Which verifies the correctness of the theoretical study and simulation analysis.(4)Based on the results of finite element analysis,carry out structural optimization of off-highway wide-body dump truck tipping mechanism.The improvement plan was proposed for the unreasonable structure of the turning mechanism.After the plan was verified to be feasible,the lightweight design of the improved product was carried out with safety and reliability as the premise,the cross section size of the main parts as the variable,and the minimum mass of the structure as the target.The final turning mechanism and frame mass is reduced by 11.61% compared with the original solution,which improves the economic and practicality of the product. |
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