Research on Template-Based Parameterized Structure Design for Drawing Dies
The structure design of drawing dies is a very compLicated and knowledge-intensive process. This paper describes a template-based parametric design system for drawing dies which adopt template as the die design knowledge base and instantiate it to complete the design of the main components of drawing die. Some key technologies such as the template technology, the parameterization technology and the top-down assembly design technique have been studied. The template for drawing dies is defined by using the "top skeleton" assembly structure, and the associative geometry-driven design and parameter-driven design of dies structure is reaLized by adopting WAVE technique and parameterized design method. The design process of template-based drawing dies structure is estabLished and the rapid design of structure is implemented by applying UG secondary development. At last, effectiveness of our method is verified by some examples.
A Knowledge-based Parametric Design System for Trimming Dies
In this paper, by analyzing the structure characteristics of trimming dies, and combining with the theory of knowledge engineering, the author expounds the system architecture of the knowledge-based parametric design system and the design methods and key points of its main modules design. At present, this system has been put into practice and has achieved good benefits.
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.