Bionic design and verification of high-precision machine tool structures

Highly stiff and lightweight machine tool structures are very important for improving machining accuracy. How to reasonably arrange stiffeners is one of the problems that designers must solve to achieve required structural performances. This paper presents a practical approach for stiffener layout design, which is inspired by the adaptive growth phenomenon observed in nature. Firstly, a mathematical model is built to provide theoretical basis for the adaptive growth of stiffeners to the applied load. Then a corresponding algorithm is developed to realize the generation of stiffener layout, during which the growth rates are determined by the generalized heights of stiffeners and the growth directions by branching and degenerating operations. When applying the approach to redesign an actual machine tool bed structure, a simple spring model is introduced, which can greatly reduce computation cost by transforming the 3D stiffener layout design problem into a 2D one. Numerical and experimental results show the stiffness enhancement, and thus, the applicability and validity of the approach are proved.