Artful surfaces: an ethnographic study exploring the use of space in design studios

A largely overlooked aspect of creative design practices is how physical space in design studios plays a role in supporting designers' everyday work. In particular, studio surfaces such as designers' desks, office walls, notice boards, clipboards and drawing boards are full of informative, inspirational and creative artefacts such as, sketches, drawings, posters, story-boards and Post-it notes. Studio surfaces are not just the carriers of information but importantly they are sites of methodic design practices, i.e. they indicate, to an extent, how design is being carried out. This article describes the results of an ethnographic study on the use of workplace surfaces in design studios, from two academic design departments. Using the field study results, the article introduces an idea of ‘artful surfaces’. Artful surfaces emphasise how artfully designers integrate these surfaces into their everyday work and how the organisation of these surfaces comes about helping designers in accomplishing their creative and innovative design practices. Using examples from the field study, the article shows that artful surfaces have both functional and inspirational characteristics. From the field study, three types of artful surfaces are identified: personal; shared; and project-specific. The article suggests that a greater insight into how these artful surfaces are created and used could lead to better design of novel display technologies to support designers' everyday work.     

Adding draft angles on mechanical components containing constant radius blending surfaces

The automation of mould design and manufacturing using computer-aided design and computer-aided manufacturing (CAD/CAM) draws the attention of many researchers. However, little attention is given to the automation of draft angles addition process. Draft angle is an important feature that facilitates the ejection of moulded parts. Existing algorithms for draft angles addition are still having limitations, especially for geometry with blending surfaces. A new approach for draft angles addition is introduced. It reduces the workload of users by automatically producing inclination on surfaces that require draft angles.     

The application of surface visibility and moldability to parting line generation

In molding, casting or forging processes, part surfaces are formed by the core, cavity and local tools in molding/casting or by the upper and lower dies and local tools in forging. In computer-aided design of dies and molds, automatic identification of surfaces molded/formed by these different tooling components is critical since the generation of parting lines depends on these surfaces, which would further influence the determination of parting surfaces, the creation of core and cavity blocks and the entire mold structure. In this paper, the surface partability and visibility are first proposed and its moldability is next presented. Considering the molding process as an instance, the concepts of core-, cavity- and the local tool-molded surfaces are defined. A methodology based on surface visibility and moldability to determine the potentially and actually moldable surfaces of these groups is developed. Since the generation of parting lines is a crucial preliminary design step in mold/die design life cycle, a new approach to determining the parting lines based on the proposed methodology is presented. A case study is used to test the methodology and approach, and to validate the efficiency in parting line generation of molded parts.     

Two algorithms for volume-preserving approximations of surfaces of revolution

The paper deals with volume-preserving approximations of surfaces of revolution. The approximating surfaces are generated only by line segments and circular arcs of a constant radius r. Further, for r > 0, the approximating surfaces are visually C¹ surfaces. For r = 0, developable C⁰ surfaces are obtained (consisting of either congruent cylinders or frustums of cones of revolution). Two algorithms are discussed. The first algorithm preserves the volume enclosed by a surface of revolution and the planes of every two latitude circles; the approximating surface is, however, no longer a surface of revolution. The second algorithm applies an approximating surface of revolution; however, the volume preservation no longer holds globally.     

三角域上带形状参数的三次Bézier曲面

张量积Bézier曲面被成功地应用于商业CAD系统中,然而实际工程中的某些外形却无法依靠张量积形式实现.因此在CAGD中,三角Bézier曲面成为外部形状设计的主要工具之一.为了更加灵活地控制三角曲面的形状,构造了一组带形状参数的三次多项式基函数,它们是三角域上三次Bernstein基的扩展.利用该组基函数定义了三角域上带形状参数的多项式曲面.基函数和曲面分别具有Bernstein基和Bézier曲面的性质.在形状参数的取值范围内,三次Bézier三角曲面是它的特例.由于含有可调的形状参数,该曲面在形状修改与变形中具有更大的灵活性.形状参数具有明确的几何意义,参数越大曲面越逼近控制网格.实例表明,通过改变形状参数的取值可以调整曲面的形状,在CAGD中该方法是有效的.     

The application of surface demoldability and moldability to side-core design in die and mold CAD

In casting, molding and forming processes, the surface geometries of the fabricated products are formed/molded by different functional components of tooling. In plastic injection molding, they are molded by core, cavity or side-cores. In die and mold CAD, how to identify the product surfaces formed/molded by the corresponding tool components for a given product CAD model is critical, as it affects the determination of parting directions, parting lines and parting surfaces, the generation of core and cavity blocks, and finally the design of side-cores and their actuating mechanisms. In this paper, the concepts of surface visibility, demoldability, and moldability are first presented and formulated. The surfaces formed/molded by core, cavity and side-cores are then defined based on the plastic injection molding process. The methodology to identifying and classifying them is further developed. By employing the proposed notions of the demoldability map of surfaces and undercut features, the most preferred demolding direction, the grouping of undercut features, and how to conduct the side-core design is articulated succinctly, and the detailed procedures and processes are presented. Through an industrial case study, the developed methodology for side-core design is systematically presented and the feasibility of the developed approaches is verified.     

Functionality in blend design

A method is presented for obtaining surfaces that satisfy certain given design conditions. The surfaces are generated as solutions to a partial differential equation and designs, which optimize some function of the surface while satisfying some other constraints, are found. Examples of maximizing the heat lost from a surface and of minimizing shear stress are considered.     

Interactive garment design

A method for the design of garments at a workstation is proposed. An underlying body form analogous to a trade mannequin is first represented in the computer. Garment panels are considered to be surfaces of complex shape, whose fit with respect to body form may vary over the surface. A method of easy entry of data for representing panels is proposed, whereby fit around panel edges can be defined. The problems of controlling fit in the interior of panels is considered and a scheme is proposed which accomplishes design with economy of effort from the designer.