Finite Element Analysis For The Key Structure Of 600t·m Dynamic Compaction Machine

As dedicated construction machinery, dynamic compaction machine is currently no national standards for design and manufacturing. At present, the structural design of dynamic compaction machine mainly references crawler cranes'mechanical system. Dynamic compaction machine has a very high load factor, sudden unloading, frequent operations and other work characteristics. The structure of the crawler crane used in the dynamic compaction has security and reliability issues. The lattice boom and chassis is the main load component of dynamic compaction machine, its mechanical properties directly affect the normal operation of machine. So the analysis of strength, stiffness and dynamic characteristics of the lattice boom and chassis is very necessary. Taking a 600t-m dynamic compaction machine as the research object and basing on the finite element method and mechanical system dynamics theory, the author used finite element analysis software Nastran and Patran, respectively, calculated and analyzed the strength, stiffness and dynamic properties of the lattice boom and chassis of dynamic compaction machine. The main work is as follows:(1) According to the mechanical characteristics of the truss structure, the author reasonably simplified the structure of the lattice boom of a 600t-m dynamic compaction machine, established the finite element model, found the results of stress distribution and displacements, and checked the strength and stiffness. The results show that the finite element method can effectively reflect the overall state of stress and the characteristics of local stress of the lattice boom. The structure of the lattice boom has sufficient strength and stiffness. These results provide basis for the further optimal design of the lattice boom.(2)By making model analysis of the lattice boom, the author got 10 natural frequencies and their vibration modes. Calculated the operating frequency of the main vibration source and concluded that the lattice boom vibration is low frequency vibration and the dynamic compaction machine's normal working will not causes the resonance of the lattice boom.(3)According to the mechanical characteristics of the chassis a 600t-m dynamic compaction machine, the author analyze the stress and deformation of the chassis in the three conditions by using the finite element method. The results showed that the finite element method can effectively reflect the overall stress state and local mechanical properties of the chassis, the structure of chassis has sufficient strength and rigidity, the thickness of some steel plate can be appropriately reduced.(4) By making model analysis of the chassis, the author got 10 natural frequencies and their vibration modes. Comparing with the operating frequency of the main vibration source on the dynamic compaction machine, the results show that the dynamic compaction machine's normal working will not causes the resonance of the chassis.(5) With lightweight as the goal, the author optimized the structure of the chassis, reduced the thickness of steel plate, and significantly reduced the weight of the chassis under the premise of ensuring strength and stiffness. After re-verifying the natural frequency of the optimized chassis, the results show that the new structure will still be able to ensure the normal operation of the dynamic compaction machine.