عنوان مقاله [English]
Physical structures in developing systems are designed to response the new needs of human beings and societies. After millions of years, the principles learned from nature are identified and they can be used to solve engineering problems as a proper design method. So, the quality and the process of inspiration from nature to achieve a product are very important. In engineering and architectural approach, these techniques and patterns are matched together, in order to achieve the optimum function and aesthetic form. Each natural structure can be used as a case study having new lessons for engineers in quality of coordinating form with structure. The bionic science, as an interdisciplinary science between metallurgy and biology, is an engineering discipline based on the lessons learned from nature. Bio-structures are studied and the relation between structures and properties are identified in bionic discipline in order to develop the process, methods and designing micro-structures for new materials. Bionic researchers identify the parameters according to the similarities between natural systems and engineering systems. The limitations of inspiration are depended on structural and mechanical differences. The objective of the biomimetics as a biological process science is to produce engineering systems which have properties and similarities to live systems or to produce engineering systems that are subordinate of live systems and also to make a rational and real balance between man and nature. So, the balance inspired from the nature, can support the human needs as well as respect the health of nature in relation with ecological systems. In this article, first, the theory of bionic science is described according to the studies and scientific experiments of the authors. Then according to the study of bionic designs which have been developed, a design process for bionic design is proposed which has six stages. To achieve a successful bionic design, the cooperation between biologists and engineers is necessary. So, the required data should be obtained from the biologists through some steps and then these data have to be adjusted to the engineering science. It looks that the bionic design is not an individual design based on the ability of designer, but it is a team work design depended on the cooperation of different disciplines. Shells are the structures with sustainable forms. They achieve the sustainability and resistance by forming according to the forces that they must bear. These curved sheets transit structural loads by tension, pressure and cutting. They are very thin structures having very low flexure lines. The crust of an egg, the crust of seeds, the brainpan of animals, a water bubble, the marine pearls, are the common shells identified in nature. The pearls are good samples for the usage of shells in nature. They have simple mathematic functions. Gastropods are a group of pearls which have a spiral form in their shell. The curved form of these pearls is the logarithmic golden spiral curve. The abalone pearl as one of numerated pearls has the spiral form in shell with a horizontal plan. Abalon pearl has some apertures on the lateral edge of the shell. The size of these apertures gets smaller across the spiral with an algorithmic pattern. In the second part of this article, according to the proposed process for bionic design, the structure and form of abalone pearl is studied. Then the algorithm of the shell of abalone pearl is derived by grasshopper software, as the parametric software which is based on mathematical relationship which prepares the ability of using primary parameters and the algorithm for identifying form. Then the optimized form of the shell structure in order to cover large spans is studied. Using the shell pattern of abalone pearl in form making of open shells can result a variety in the forms based on the spiral. Conclusion of this paper prepares a scientific base for future studies on resistant and sustainable natural forms and their usage in architecture and building industry.