Numerical Simulation of Temperature Field for Laser Rapid Prototyping
The temperature field model for laser rapid prototyping is established by the mathematical treatment of laser power input. Temperature fields with different process conditions are numerical simulated, and the temperature is Gaussian distribution as the intensity distribution on laser beam cross-section. Temperature fields for laser rapid prototyping ware measured by thermal imager in real time. The simulation results agree with the experimental measurement. Experiments show that the temperature field model can be used for computer analysis and optimizing of laser rapid prototyping processing.
Determination of the optimal build direction for different rapid prototyping processes using multi-criterion decision making
Rapid prototyping (RP) is an emerging technology for creating physical prototypes from three-dimensional computer aided design models using the additive process with layers. In order to use the process efficiently, several important factors must be considered. The ability to select the optimal orientation of build-up is one of the critical factors since it affects the part quality, build time, and part cost. This study aims to determine the optimal build-up direction of a part for different RP systems. The revised average weighted surface roughness, which considers stair stepping effect, build time calculated by laser/knife/nozzle travel, and part cost calculated by build cost rate, labor cost rate, material cost, etc., are considered. Among the orientation candidates chosen from the convex hull of a model, the best orientation is selected using the simple additive weighting method, a widely used multi-criterion method for decision making. The best orientation is also identified for each criterion. The validity of the algorithm is demonstrated by several examples. The algorithm can help RP users select the best build-up direction of the part and create optimal process planning.
Increased accuracy by using dynamic finite element method in the constrain-surface stereolithography system
Abstract The E-DARTS apparatus is a commercial rapid prototyping (RP) system that uses the constrain-surface stereolithography (SL) technology. The advantages of the type SL system are saving resin and apparatus fees, although its accuracy needs to be increased. To find the best scanning path planning is one solution to improve the accuracy of the built part. In this paper, the diagnostic H-4 parts have been fabricated and simulated according to different path plans. The critical dimensions of the built H-4 diagnostic parts are also measured and compared with the analytical results, showing that the best path plan for building the H-4 diagnostic part is the contour-out path. In addition, it has been shown that using the skip skill in raster fill is also effective for improving the full filling of the big or long area.