Principle of constant stress in analytical form-finding for durable structural design

The paper presents examples of nature-inspired structural forms modelled using a form-finding approach that preserves the principle of constant stress in structures under statistically prevalent load. It is a principle observed in highly optimized natural objects, such as: trees, bones, or shells, and one that can be used to model shapes of a variety of engineering structures, ranging from roofing forms to arches. Its main advantage is that it produces structures characterised by a minimal stress response to loading. While constant stress roofing forms (minimal surfaces) have a limited design space determining their existence, it is found that the same applies to arches of constant axial stress. Despite that, the design space is very large, allowing an enormous number of natural designs to be created. It is suggested here that the principle of constant stress should be used as the main optimisatio criterion in generating durable and sustainable design solutions.