Crack Propagation Of Crane Girder Based On Hybrid Model Of Peridynamics And Finite Element Method

Efficient and accurate simulation of crack propagation in large mechanical equipment has always been a hot topic in computational mechanics.Peridynamic method has been widely used in simulating crack growth,but it also exposes the problem of low computational efficiency.There is a contradiction between continuity theory and discontinuity problem in finite element method in simulating crack growth.In this paper,a hybrid model is established by combining the two methods.The peridynamic method is used to calculate the crack damage area of crane girder,and the finite element method is used to calculate the other areas.By setting the interface element at the junction of the two sub-regions,the displacement coordination method is used to connect the two sub-regions.The hybrid model is applied to simulate the crack propagation of crane girder,the accuracy of the model and algorithm is verified by Ansys and experiments.Firstly,the basic theoretical knowledge of peridynamics and finite element method is introduced,including basic theory and numerical calculation method.Combining the numerical methods of peridynamics and finite element,a hybrid model of crane girder is established according to the material characteristics of crane girder,and the modeling process is introduced in detail.The analysis program is compiled by the software of Matlab,and the hybrid model is numerically realized.The validity of the model is preliminarily proved by a simple example.The hybrid modeling methods in this paper and other literatures are compared,which proves the superiority of the hybrid modeling method in this paper.Then,the peridynamics and finite element method are used to simulate the crack growth of crane girder model with initial cracks.The modeling method in this paper and other modeling methods are compared and analysed,the advantages of the modeling method in this paper is illustratd.The algorithm is designed in the finite element software Ansys,and a set of analysis program which can automatically simulate the crack growth is obtained.The application program simulates the crack growth of the crane girder model and obtains the finite element analysis results.The simulation results of traditional finite element software Ansys and hybrid model are compared and analyzed,which verifies the accuracy of hybrid model in simulating crack growth.Finally,the three-point bending test is carried out with the test sample,and the mechanical behavior of the test sample under three-point bending,such as deformation and crack initiation and propagation,is tested.The results are compared with the results of peridynamics and finite element hybrid model simulation,which further verifies the accuracy of the hybrid model.