Bending characteristics analysis and lightweight design of a bionic beam inspired by bamboo structures

In this paper, a bionic bamboo beam composed of bionic bamboo tubes and bionic bamboo diaphragms is first presented, which is inspired by the macro structures of bamboo due to lightweight characteristics of bamboo in nature. Then, the bending model of bionic bamboo beam is established on the basis of the Euler-Bernoulli beam theory. The correctness of the model is verified by comparing the results by its own compiled code with those by the finite element method (FEM). The effects of wall thickness of bionic bamboo tube, number of bionic bamboo diaphragms and wall thickness of bionic bamboo diaphragm on the bending characteristics of bionic bamboo beams are also analyzed. On the basis of that, the lightweight design of bionic bamboo beam is established by using the response surface method (RSM). The results show that the P1ON2 is 3.9% lighter than hollow beam C10T7, and 45.1% lighter than solid beam S10B. Further, the three point bending test is used to verify the correctness of the optimization results. Test models of P10N2, C10T7 and S10B are obtained by using the SLA 3D printing technology. Experimental results show that the relative bending resistance of P10N2 is 234% of hollow beam C10T7 and 271% of solid beam SlOB, respectively. It is verified that P10N2 is the optimized lightweight bionic bamboo beam. The research in this paper provides new ideas and methods for the design of beams and rotors.