Based On The Morphology Of Leaf Venations As To The Design Of Stiffeners On Plate-shell Structures

The plate-shell structure is applied extensively in the engineering,and it is a very effective method that stiffeners are installed in order to ensure the overall stiffness and also not increasing the thickness of plate and shell.Based on the distribution of plant leaf venations and combined with the structural optimization of plates and shells,the bionic design has been researched according to three major elements of the stiffener concerning plate-shell structures: the variables of type design,location design as well as dimension design.Subsequently,these tasks(such as the similarly verified analysis,the simulation of distributional pattern on plant leaf venations,the analysis of structural optimization,the inductive design of bionic design scheme on stiffeners and the simulation analysis of engineering application and so on)were conducted.Specific tasks can be summarized as follows:First,the collection of evaluation factors(such as structure,function,adaptability,working conditions,etc.)was established by the common and similar characteristics between plate-shell structures and plant leaves,and on the basis of those,judgment matrix was set up and consistently checked,thus similar weighting coefficient was concluded;according to the ratio of similar elements characteristics about two fuzzy system,the similarity of similar element was obtained between the plant leaves and the structures of plate and shell.The results have shown that both the similarity of them is higher,which is in line with bionic needs,and the plant leaves are identified as the bionic object of stiffeners;Secondly,based on Establish three types of the model of plant leaves formed by the structure of plant leaf and the distribution of plant leaf venations with wine-rained induction,which shows that the medial axis pattern is identical with the actual distribution of venations in accordance with the venation acquired by the simulation,the correctness of optimization method was verified.In terms of this,the distribution of plant venations was analyzed and summarized.Third,after structural topology optimization,the idea was that the arrangement and the design of size on stiffeners were provided by the distribution position and concentration of material.Based on the comparative results of structural optimization and the conclusion of bionic design scheme about stiffeners combined with the distribution of venations,based on the bionic scheme and aimed at the structural characteristics,the bionic design was conducted through the model of plate-shell structure,the bionic design and the traditional design were compared,and then the results of one demonstrated that under the premise there were almost total mass between bionic structure and traditional structure,both of the structural deformation and maximum stress of bionic structure were less than the traditional one,so those proved the validity and practicality of bionic design in this paper;Finally,the irregular and curved-surface shell structure of aircraft's skin and the planar shell structure of urban bus' body were respectively designed as stiffeners bionic,the applications of bionic plates stiffeners were further explored in practical engineering.The results of two applications displayed that on the condition that the mass of bionic model is equal to the traditional one,the deformation of bionic model and the stress are much smaller than the traditional one;however,the structural stiffness and intensity are greatly improved.The bionic tendons play an effective role in resisting structural deformation and rapidly transmitting the force,which indicated that on the basis of leaf venations,the design of plate-shell structures of is reasonable and effective.