Adaptive structures and design concept of transformable joints

Abstract

This article describes the research framework for adaptive structures and the design concept of transformable joints. The research of adaptive structures can be splitted into different scales: deformation mechanisms (whole structure), cooperation mechanisms (inter-component) and actuation mechanisms (intra-component). This research will focus on transformable joints, which are based on special material properties (actuation) to accomplish the change of joint stiffness between locked and released states (transformation). Thereby, the control of DOF can be achieved, in order to finally realise the whole structure's form change (deformation). Alternatively under shock loads, the joints release and the structure occur certain deformation to dissipate energy and adjust to external loads. Afterwards, the structure recovers its original shape and removes residual strain through special/smart materials. Then the released joints relock again. By comparison of natural role models and adaptive structures, there are many similarities between them that we can learn from nature. In future research, e.g. adaptive stiffness, the experimental tests of potential materials and prototypes will be the main research methods. While for adaptive geometry, the knowledge of robotics, especially the part of geometric representations and transformations, will help to express this problem in mathematical way. This part will be mostly in conceptual level, so computer simulation will be used. The final goal of this research is to develop energy dissipation and shape-morphing strategies using transformable joints under varying loads as well as shock impact. These kinds of joints can not only be applied to tessellated shell structures, but also introduced to active facade systems.