Study On Fatigue Life Of Agitator Truck Based On Finite Element And Multi-rigid-body Dynamics

With the development of circular economy,and the six standard come on stage,mixing car industry began to enter into the age standardization,the trend of heavy machinery lightweight irreversible,and this requires mixers products at the beginning of the design is not only to meet the lightweight needs of customers,also need to satisfy the use requirement have enough fatigue life.Only in this way can we increase our market share and have more customers.Based on Hyper Works,this paper analyzes the stiffness and strength of a mixer under normal driving conditions,establishes a four-bridge vehicle system dynamics model based on ADAMS/ CAR,and studies the fatigue life of a mixer by using Design Life.The three-dimensional model of the mixer was discretized into a finite number of continuous units,and the grid model of the vehicle was created.Then the cards of different conditions were set for static analysis.Finally,according to the result cloud map,it was found that the structure of the mixer met the basic rigidity and strength conditions.By comparing the simulated stress data with the original test data of the agitator,it is found that the two data are close to each other,which verifies the correctness of the analysis.Based on the traditional three-axle model,a second front suspension is added on the basis of the first front suspension,and a double front suspension system is created.With other systems,the four-axle dynamic model of the agitator is completed.The model parameters of each system are adjusted according to the actual parameters of the agitator,and the dynamics simulation of the vehicle is realized after overcoming the problems of communicator matching and constraints.According to the actual road surface of the mixer,the two-dimensional random road surface was selected as the excitation input of the road surface,and the load time history of the mixer frame was output after the simulation of different events.By comparing the acceleration data obtained from simulation with the experimental data,the correctness of the simulation is verified.The total fatigue damage of the components on the agitator vehicle was calculated by inputting the stress results,the fatigue characteristic curves of the materials and the load spectrum in Design Life,and the fatigue life of each component under the current stress was obtained.The cloud image shows that the fatigue life cycle times of each component on the agitator are greater than the fatigue turning point,and the whole has a good fatigue life.Then the life value of the fatigue damage risk area is compared with the stress value,it is found that the stress safe part also has the risk of fatigue failure,which verifies the importance of fatigue analysis.The strength check of the parts should consider not only the static load safety but also the dynamic load safety.The study of this paper makes up for the shortage of analysis in single aspect and has great significance for the research on the lightweight of the stirring truck.