Xiaobing Dang

Mechanical Properties and Manufacturing Process of a Closed-Cell Cellular Metal Based on Cubic Structure

It is well known that cellular metal is an ideal structure used in transportation passive safety field for its low density and high energy absorption capacity. In this paper, a kind of regular cellular metal based on cubic structure is proposed. The cubic cells are manufactured through sheet metal stamping process. Then the cells could be bonded together by adhesive to form the cellular structure. The compressive properties of the cellular metal are studied by experiments. The dynamic behaviors are studied by numerical simulations. To distinguish the individual and interactive effects on the energy absorption capacity, a full factorial Design of Experiment with sixteen configurations is carried out based on the four parameters that are essential to the design of cellular metal. The effects of impact velocity on crushing deformation are analyzed. It has been shown that the regular cellular metal based on cubic structure will have a wide application in industry.Copyright

A Novel Incremental Bending Process of Complex Curved Sheet Metal

The bending of complex curved sheet metals of ship hull has long been a challenge in shipbuilding yard on account of some inherent defects of the traditional forming processes such as the line heating. This paper presents a novel incremental bending process based on punching to obtain complex curved steel plates in order to take the place of those inefficient traditional forming processes of ship hull.The presented incremental bending process is carried out by a series of stepping punches, so it is also defined as incremental punching in this work. By means of this process, the blank plate that is fixed and held by a flexible supporting system can incrementally be bent to the target shape by a press tool with a planned tool trajectory one step after another. Meanwhile, in order to improve geometric accuracy of the formed work-piece, a 3D scanning feedback system is applied to measure the deformation of the work-piece during the forming process. Three dimensional shape of the formed work-piece can be imaged and rebuilt with a large amount of point cloud data by the 3D scanning feedback system. Then the difference between the rebuilt model of the formed work-piece and the target CAD-model can be acquired, which can be used for feedback control of the forming accuracy if necessary.To validate the presented forming process, an original incremental punching prototype was designed and manufactured, which is mainly composed of a 3-axis CNC machine, a flexible supporting system and a 3D scanning feedback system. A forming experiment of a gradual curvature steel plate was carried out using this prototype and is discussed in detail in this paper in order to demonstrate the feasibility of the proposed incremental bending process of complex curved steel plate.Copyright