On the Dynamical Tendency of Intuitively Designed Shapes

在各种简单的物体中，我们可以找到有效避免应力集中的形状。这些形状可以在物体的结构元素中观察到，这些元素表现出一些简单的形式。这些元素可以在许多历史产品的设计中找到，例如农具，机床，经典汽车以及现代机器。大多数元素都是在给定情况下根据经验获得的一些知识直观地设计出来的。在形状的应力分布中观察到的动力特性之一是应力相干性。以啤酒杯手柄为例，直观地设计了一些形状，并用有限元方法对形状特征进行了分析。结果表明，形状的审美可取性与应力一致性之间存在明确的关系。有人进一步建议，旨在再现引起这种一致性的结构特征的计算机辅助设计系统将能够以数字方式设计复杂的形式。如果一个设计系统能够产生连贯的形状，那么设计感和设计过程的协调就可以实现，同时也可以避免应力集中。最后，我们尝试提出一种形状设计方法，模仿自然界中生长的过程，这通常是一种避免应力集中的机制。这种方法可以成为设计包含应力相干性的形状的基本系统之一。

In various simple objects, we can find shapes that effectively avoid stress concentration. These shapes can be observed in the structural elements of objects, and these elements show some simple form. Such elements can be found in the design of many historical products such as agricultural tools, machine tools, and classic cars as well as modern machines, Most of the elements have been designed intuitively with some knowledge obtained from experience in the given situation. One of the dynamical characteristics observed in the stress distribution of the shapes is stress coherence.As a case study, some shapes for beer mug handles were designed intuitively, and the characteristics of the shapes were examined using finite element analysis. As a result, it was demonstrated that there is a clear relationship between the aesthetic desirability of shapes and stress coherence. It was further suggested that a computer aided design system intended to reproduce the structural characteristics which induce such coherence will be able to design complex forms numerically. If a design system is able to produce shapes displaying coherence, coordination of sense of design and the design process can be expected as well as avoidance of stress concentration.Finally, we tried to propose a shape design method which would imitate the process of growth found in nature, which is generally a mechanism that avoids stress concentration. This method could then become one of the basic system for designing shapes containing stress coherence.