Research On Topology Optimization Design Of Crane Box Girder Structure

With the rapidly development of technology, the enlargement of production scale and the raising of automation degree, the crane is used more and more widely. It plays a more important role in industry. It is very essential to raise the crane's production efficiency, to reduce the cost of materials'transportation and to ensure the safety of operation.Using the box girder of the crane as the research object, combining the finite element method and the topology optimization of modern design methods, and applying the alterable density method and the ANSYS software, the topology optimization design research of the crane's box girder is completed. The new structures of the hollow trunk girder and the oblique reinforcement girder are introduced. Analyzing the stiffness, and strength of the traditional girder, the hollow trunk girder and the oblique reinforcement girder by ANSYS software, the results show that the topology optimization of the crane's box girder is reasonable and feasible. The weight of girder is decreased and the cost of manufacture is reduced.The topology optimization model of box girder is established. Using the alterable density method and ANSYS software, the topology optimization design of the box girder and the solid girder are completed and the optimal topological structure of the girder is achieved. The optimal structure of the box girder is the arc shape under the uniformed load and the M-type shape under concentrated load. The optimal structure of the solid girder is similar with the inverted V shape under the concentrated load.According to the topology optimization for the box girder of a 30t straight-path double-girder crane, the hollow trunk structure of the girder is given for reducing the weight of the girder. Calculating and analyzing with the classical mechanics, the hollow trunk girder's stiffness and strength have little change by comparison with traditional box girder and can satisfy the requirement of crane's strength and stiffness. But the weight of the hollow trunk girder is decreased a lot.The ANSYS models of the traditional box girder, the hollow trunk girder and the oblique stiffener girder are established. The ANSYS analysis calculation is finished. Compared with traditional box girder, the hollow trunk girder's stiffness and strength have little change but the weight is decreased a lot. The stiffness of the oblique stiffener girder is almost the same with the traditional box girder but the strength and weight is reduced a little.The research raises the structure design level of crane's box girder and makes the girder structure to be more reasonable. At the same time, it has the directive sense and the higher reference value for the structure design of the crane's box girder.