| Since the outbreak of the new crown epidemic,the world economy has encountered great resistance to development,China’s high-tech manufacturing industry has bucked the trend and achieved sustained growth,and high-tech manufacturing is gradually becoming a new driving force to support the high-quality development of the manufacturing industry,the development of high-end manufacturing has further increased the demand for telescopic boom crawler cranes in the market.Compared with truck cranes,telescopic booms of crawler cranes need to additionally meet the functional requirements of driving with a load.Compared with truss-jib crawler cranes,telescopic boom crawler cranes differ significantly in the way they restrain their lifting arms.It is therefore essential to study the performance of the telescopic boom system when traveling with a load and the dynamic characteristics of the machine.In this paper,a model of a telescopic boom crawler crane is analyzed and the dynamic characteristics under different operating conditions are investigated.The main research contents and methods are as follows:(1)Analyse the structure of the telescopic boom and the forces on each boom section,establish a spatial dynamics model of the telescopic boom traveling with a load,simplify the model,and then calculate and solve the forces on the telescopic boom from the wire rope.(2)Analyse the components of the crane off-loading system,use the LM low-speed crawler module of Recur Dyn to model the crawler system according to the parameters of the crawler model,import the crawler chassis and the 3D model of the rest of the main components of the off-loading,and set up the movement when between the components to complete the establishment of the crawler crane off-loading motion system.The relationship between the joints of the telescopic boom is analyzed and simplified,and the flexible telescopic boom model is built using Hyper Mesh software.The flexible telescopic boom model under the three operating conditions is exported from Ansys and imported into Recur Dyn as a flexible boom,and the connection is established with the crawler crane dismounting system to complete the establishment of the rigid-flexible coupling dynamics model of the telescopic crawler crane.(3)Set the drive wheels of the crane to drive,and analyze the dynamic characteristics of the telescopic boom under the rigid road surface under the working condition of driving in a straight line to verify the accuracy of the dynamics calculation results,and then change the driving speed and driving acceleration to obtain the dynamic load coefficients of the telescopic boom under different acceleration and deceleration of the rigid road surface and different speeds.(4)The dynamic characteristics of the telescopic arm on the rigid ground and on three different flexible road surfaces are compared and analyzed by changing the road surface properties and simulating the linear driving conditions of the crawler on dry sand,clay and sandy loam road surfaces,and determining the dynamic load coefficients of the telescopic arm on different road surfaces respectively.(5)Using APDL language,each arm section is assembled according to the three arm lengths,contact is established between the arm sections and the slider,constraints are set at the articulation between the telescopic arm and the turntable and the telescopic arm and the hydraulic cylinder,and loading is carried out according to the dynamic load coefficients in the standard and the dynamic load coefficients obtained from the simulation,and the static analysis and modal analysis of the telescopic arm under the three arm lengths are completed.The static calculation results are analyzed to summarize the deformation and stress distribution law of the telescopic arm under different dynamic load coefficients. |
