Research Of Fatigue Life For Compactor Structures Based On FEA

With the development of the tamping method, dynamic compaction machine comes into being as an equipment used for ground consolidation, which has a wide variety of types, such as frog rammer, jump rammer, paving beater and weighted hammer and so on. The compactor researched in the paper is weighted hammer. The hammer is raised to a certain height by the dynamic compaction machine repeatedly during operations, and then it will be unhooked by the release device or on the rope. In the dynamic compaction process, the enormous impaction affects fatigue life of the structures which is brought by the hammer lifting repeatedly and the hammer falling to the ground, that also affects the compactor’s asset life, safety and production cost, so the research on life of the dynamic compaction machine is quite important at the beginning of the design.Finite element’method is applied in the paper, and it gains stress-strain by ANSYS software, gains stress-time curves by ADAMS software, which are extended to form load spectrum, and at last calculates fatigue life by FATIGUE software. The main study in this paper is as following:(1) Introducing steps in the Finite element method, transmissions of the interface files among softwares and the detailed flow chart of the fatigue analysis based of Finite element method.(2) The appropriate method is chosen, combining the compactor’s operating characteristics, then the compactor’s fatigue life is calculated, life nephogram is checked, and the failure structures are improved pertinently. At last its feasibility can be validated by the FEA result and fatigue analysis result.(3) As to study the influence of different boom sections to fatigue, some common steel products, such as circular pipe, square steel, angle steel and H steel, are used to establish the boom model separately. And then their fatigue life is calculated, and their anti-fatigue capabilities are contrasted.(4) In the dynamics simulation, study on the rule how the factors impact the dynamics characteristics of the overturn protection of jib and the compactor, such as length of boom, spring stiffness coefficient and boom angles at the time of overturn protection of jib reacting and so on. In this paper, the virtual prototype is modeled to calculate fatigue life at the beginning of the design, then the failure structures are found out and improved on pertinently, in order to avoid illogical life-span distributing ahead of time, to enhance the probability of the engineering sample passing tests, so this method can curtail time for study, reduce cost for design and increase market competition.