An error diffusion based method to generate functionally graded cellular structures

The spatial variation of cell size in a functionally graded cellular structure is achieved using error diffusion to convert a continuous tone image into binary form. Effects of two control parameters, greyscale value and resolution on the resulting cell size measures were investigated. Variation in cell edge length was greatest for the Voronoi connection scheme, particularly at certain parameter combinations. Relationships between these parameters and cell size were identified and applied to an example, where the target was to control the minimum and maximum cell size. In both cases there was an 8% underestimation of cell area for target regions

Utilizing the Design Freedoms of Rapid Manufacturing to Optimise Structural and Acoustal Interactions of 'Brass' Musical Instruments

The feasibility of the production of end use ‘brass’ musical instruments using Rapid Manufacturing (RM) is discussed with an emphasis on optimising the structural resonance through stiffening structures. The method is based upon a coupling between the air-column and structure when their resonant frequencies approach each other, which accentuates the players’ lip to wall coupling effect. The degree of wall vibration and the frequencies at which it occurs can be controlled by variation of the structure’s stiffness and the design freedoms allowed by RM enable greater control of this. Initial results of the structures and their performance are presented.Mechanical Engineerin