مدل شبیه سازی برای ساخت قطعات ساخته شده از مواد چند حالتی مناسب

A component, which has an optimized combination of different materials (including homogeneous materials and different types of heterogeneous materials) in its different portions for a specific application, is considered as the component made of a multiphase perfect material. To manufacture such components, a hybrid layered manufacturing technology was proposed. Since it would be risky and very expensive to make such a physical machine without further study and optimization, manufacturing simulation is adopted to do further research so as to provide the reliable foundation for future practical manufacturing. This paper describes its virtual manufacturing technologies and modeling of the component virtually manufactured. Such a model can be used to evaluate the errors of the virtual manufacturing. Finally, an example of simulating manufacturing process and generating the model of the component virtually manufactured is introduced in more detail.

With the rapid development of high technology in various fields, there appear more special functions of the mechanical components or products, which may require component to possess some special properties. Since homogeneous materials cannot satisfy these requirements, attention has been paid to heterogeneous materials, including composite materials (CMs), functionally graded materials (FGMs) and materials with a periodic microstructure (MPMs). However, components made of one heterogeneous material may not meet all special requirements in its different portions. To satisfy all the requirements, it would be necessary to use components made of different materials, including homogenous materials and the three types of heterogeneous materials, thus satisfying all special requirements in different portions and also making the best use of different materials. Such components can be compared to certain natural organisms (e.g. bamboo, tooth and bone). A component, which has an optimized combination of different materials (including homogeneous materials and different types of heterogeneous materials) in its different portions for a specific application, is thus considered as the component made of a multiphase perfect material (CMMPM). To design and represent such components according to requirements from high-tech applications, a corresponding computer-aided design method [1] (including both geometric and material design) and a corresponding CAD modeling method [2] and [3] (containing both geometric and material information) have been successfully developed. Currently the researches about how to fabricate such components are rarely reported in the published literature. Shin et al. [4] proposed to apply layered manufacturing technology to fabricate heterogeneous objects. However, the existing layered manufacturing methods of heterogeneous objects have some limitations and cannot satisfy the requirement for manufacturing CMMPMs. For example, in the process of direct metal deposition [4], the voids of microstructures on previous layers will be deformed due to high temperature of laser when laser micro-cladding adds materials on the current layer. Shape deposition manufacturing [5] cannot create very small and precise voids for periodic microstructures (down to less than 0.1 mm) because it is difficult to fabricate the milling cutter with such small sizes (down to less than 0.1 mm). Three-dimensional printing [6] cannot add different materials with variational volume fractions

Since there are the differences between optimal layered manufacturing thicknesses in different material regions, the generation of manufacturing sequence is required and the corresponding method is introduced in the paper. Based on theories and methods for the behavior models of spraying and the model of a component virtually manufactured, a virtual manufacturing system is developed, which can simulate behaviors of spreading, engraving, milling and grinding operations, record fabrication data in the course of virtual manufacturing, and inquire the geometric and material information of components manufactured virtually. This paper further use a CMMPM as an example to introduce the simulation of manufacturing the component, which has actually verified the functions of the developed system (for example, the component can be virtually manufactured, its required microstructures can be created, and its virtually manufactured component can be inquired). Our ongoing work is establishing an assessment approach to evaluate the errors caused by the virtual manufacturing and optimize related parameters. These simulation results will provide the reliable base for the design and manufacture of physical manufacturing facilities with a much better prospect of success, a shorter lead time, and a much lower investment cost.