Finite Element Analysis And Optimization Of The Upper-car Of Bridge Inspection Vehicle

The bridge inspection vehicle has become an indispensable special equipment in the professional bridge test field. The truss type bridge inspection vehicle represents the mainstream developing direction of bridge inspection vehicle, and has a broad market prospect. The finite element method was used to carry on finite element analysis and optimization of the upper-car of the truss type bridge inspection vehicle in the paper.The paper carefully studied the working principle of bridge inspection vehicle and the characteristics of the upper-car structure, made a reasonable model process and simplification of the components of the upper-car of bridge inspection vehicle, and used the HyperMesh software in the reasonable mesh generation of the partial model. In order to reflect all the features of the model as possible, the paper mainly applies the shell elements shell181 to simulate structure components, uses the bar beam structures to simulate the connection relations of the components, including using the Node DOF Coupling and establishing the Adjacent Regions Constraint Equation and other methods to make the model returning to the actual situation maximally. Through the above work, the paper establishes the finite element analysis model of the upper-car of bridge inspection vehicle finally.The paper made the linear static analysis and modal analysis on the upper-car of bridge inspection vehicle. The linear static analysis is the general method of the structural analysis, applying to the smaller deformation structure. Through the linear static calculations, the paper studies and analyzes the strength and stiffness of the upper-car of bridge inspection vehicle. In modern industry, the dynamic analysis has become an essential step in product design process, and the modal analysis is the most important segment in the dynamic design. The paper introduces the basic theory of the modal analysis briefly, applies block Lanczos method to the modal analysis on the upper-car of bridge inspection vehicle, and gets the inherent frequency and vibration mode of the upper-car structure.Many problems exist in the finite element analysis of the upper-car of bridge inspection vehicle, such as more calculation cases,lower calculation efficiency and etc. This paper uses languages such as DOS language,ANSYS parametric design language APDL,VBA in developing the upper-car's parameter calculation program of the bridge inspection vehicle and realizes many cases calculation which greatly improve the calculation efficiency and simplify the results process.This paper tests the displacement of the upper-car of bridge inspection vehicle, and also checks its strain of the structure by electrometric method. Through the displacement test results and strain test results, we could get the stiffness and strength of each measure point of the bridge inspection vehicle in actual measurement condition. The comparison on the test results and calculation results verified the rationality of the upper-car's finite element analysis model and the accuracy of calculation results.According to the finite element analysis results of the upper-car of bridge inspection vehicle and the domestic and foreign similar bridge inspection vehicle design experience and characteristics, the paper conducts structure improvement and optimization on the upper-car of bridge inspection vehicle, and carries on the linear static analysis on the improved model. Analysis results show that the model's strength and stiffness are remarkably enhanced after being improved, at the same time; it realizes the purpose to reduce the upper-car's weight. In conclusion, the improved structure of the upper-car not only advanced the performance, but also reduced the cost of the vehicle manufacturing; thereby it achieved the purpose of structure improvement.