Opening Shape Dynamic Optimal Design Of Revolving Shells

This paper introduces the development and application of revolving shell structure with opening and describes the present domestic and foreign situation of structure optimization. According to the time-consuming problem caused by using finite element method to solve the complex response, article puts forward a sequential response method based on inherited uniform design optimization. And on that basis, carry out the opening shape optimization of revolving shells to improve the structure dynamic performance. The main work and conclusions are as follows:First, proposed a sequential second order respond surface modeling method, which is based on inherited uniform design sample points strategy and an adaptive rule of sub-region move-limit and zooming. Verify the validity of the proposed method through typical numerical function tests and engineering cases. Provide an effective method for engineering optimization design of time-consuming problems.For the shape optimization of revolving shell’s hole, defined the parametric expression of opening’s closed curve with super-elliptic equation based on the parameter mapping transformation, realize high precision of curve fitting by quasi arc length interpolation point generating method, ensuring fast modeling of structure. Results show that using the super-elliptic function to describe the shape of hole can effectively expand the gap between first and second order frequency, reduce stress and improve buckling load.The transverse shear stiffness of the composite is much smaller than the longitudinal tensile stiffness, and the transverse shear effect affects greatly on bending deformation, vibration frequency and the elastic buckling loads. Therefore, conducts the research to maximize the frequency gap between first and second order of the composite conical shell structure by optimizing shape of hole. Select 0° and 90°, 45° and-45°, two sets of orthogonal angle, to optimize openings shape of conical shell layered fiber in different angle combination. The results show that in the same layer conditions, super-elliptic hole is better than the circular opening. However, with different boundary function of openings, the cones having maximum frequency gap is different in fibers laying angular combination, so a synchronous optimization of the fiber layer parameters and hole shape parameters can further improve the frequency gap.