Papers by Author: Hu Zhu

Abstract: The offset models of STL (Stereo Lithography) are useful in many applications such as interference-free tool path generation in numerical control machining, hollow or shelled model generation in rapid prototyping. So the methods for STL model offset are very important. In the paper, an overview of the STL models offset methods is presented in brief.

Abstract: Two kinds of methods for the control of the gap between pressing tool head and support in CNC incremental forming have been discussed (i.e. pressing path adjustment method and support shape adjustment method), and whose effects on forming accuracy are analyzed by using the Finite Element Analyses. The methods for the generation of pressing paths and supports have been given for the two forming method of the pressing path adjustment and support shape adjustment, and the Finite Element Analysis models have been built for them respectively. The method of digital simulations for the two forming cases mentioned above based on the ANSYS/LS-DYNA software has been presented and the forming precision of the two forming methods are analyzed through the comparison of digital simulation results.

Abstract: The sheet metal CNC incremental forming is a flexible dieless forming technology that forms a sheet part by extruding the sheet metal point by point with the movement of forming tool along the forming path. The tool paths therefore have a great effect on the dimensional accuracy, surface quality and forming time. In this paper, an overview of the research status about the forming tool path generation for sheet metal CNC incremental forming is presented briefly.

Abstract: To lay the foundation of the automation for line heating forming, a method for heating path generation and simulation for ship plate steel base on STL mode was proposed in this paper. The line heating path was generated by slicing the STL model of the steel plate using a series of planes, and the models of the heating equipment of ship plate steel were build, and the heating process of ship plate steel can be simulated by inputting the models of the heating equipment into the simulation system that was built by using VC++ and OpenGL. The case study shows that the method can primely solve the inconvenient of manual heating and the whole heating process can be observed by the simulation so that the heating process can be made a reasonable monitoring, and the heating path generation and simulation software are runs stably and reliably.

Abstract: On the basis of the analysis for the reason that causes the errors of the vertex offset, the accuracy improvement method for the STL offset model which was generated by the vertex offset algorithm was proposed by using the surface subdivision algorithm based on the center of gravity on triangular facets. The offset point of the center of gravity was generated by offset the center of gravity along the normal vectors of the triangular facets on which the center of gravity is located, and the new triangular facets are formed by connecting the offset points of the center of gravity and the offset vertexes of the triangular facets so that the more accurate offset model to be built. The case study shows that the proposed algorithm has higher accuracy than the existing vertex offset algorithm.

Abstract: A method of the digital simulation for the sheet metal CNC incremental forming was proposed based on the Z-map model. The tool extrusion movements were divided into two types according to the principle of sheet metal CNC incremental forming, i.e. vertical movement and horizontal movement. The vertical and horizontal swept volumes of the tool were built to intersect with the Z-map model of sheet metal respectively and the simulation models were generated. The thickness of deformed sheet metal was predicted and the thickness distribution chart was generated. The case studies show that the method can be applied to NC code verification, forming parameters optimization and formability prediction, moreover the system runs stably and reliably in the whole simulation process.

Abstract: The method of laser inner engraving path generation and simulation for crystal glass is presented based on STL(Stereo Lithography) model. To generate the laser exposure points that are adaptive to the surface of model, the contour lines are obtained by cutting the STL model with unequal distance using a series of plans that are perpendicular to Z-axis. Then the contour lines are offset and scattered, and then the path is generated by sorting and connecting each discrete point in order. Simultaneously, simulation method of laser inner engraving for crystal glass is also proposed. The case studies show that the method can primely realize the engraving path generation and the simulation for the laser inner engraving of crystal glass, and that the system runs stably and reliably.