Abstract:
The present application provides a thin-walled shell model updating method and system. The method includes converting an influence of fine feature structures in a space shell structure on stiffness and mass equivalently onto a skin and a stiffener, so as to simulate the influence of the fine feature structures on a bearing capacity of a whole structure.
Abstract:
An intelligent layout design method of curvilinearly stiffened structure based on image feature learning. Firstly, the design variables of the curvilinearly stiffened structure are determined based on the path function. The autoencoder network is built to complete the learning of the structural characteristics of the image, and the transfer learning of the model is further carried out. The convolution neural network is built to complete the learning of the image set with mechanical response labels. Finally, the evolutionary algorithm is used to optimize the layout of the curvilinearly stiffened structure based on the model. The invention solves the problem that the traditional optimization method is difficult to deal with the optimization design with many and variable design variables, and is expected to become one of the most potential technical means involved in the layout design of components in the engineering field.
Abstract:
A method for establishing a geometrical imperfection database of aerospace thin-walled structures is disclosed. The method comprises the following steps: 1) design the shell quality inspection card that is suitable and convenient to measure the geometrical imperfections for field workers. Obtain the parameters and geometrical imperfections of shells by filling data of measurement points in the shell quality inspection card; 2) perform characteristics combing, mathematical description and component analysis for the geometrical imperfections obtained in the first step; 3) collect and analyze the geometrical imperfection information of multiple aerospace thin-walled shells and establish the geometrical imperfection database based on the first step and second step. The method will effectively serve the development of aerospace equipment, shorten the design cycle and provide guidance and specifications for the design of the thin-walled components carrying main load.
Abstract:
A method for determining a reduction factor of a bearing capacity of an axial load cylindrical shell structure relates to stability checking of main bearing strength thin-walled members of aerospace and architectural structures. Different from experiment experience-based conventional defect sensitivity evaluating method represented by NASA SP-8007, a depression defect is introduced in a manner of applying a radial disturbance load. First, an influence rule of a depression defect amplitude of a single point to an axial load bearing capacity is analyzed by using numerical values, so as to determine a load amplitude range; then, defect sensitivity analysis is performed on depression defects of multiple points; then, experiment design sampling is performed by using load amplitude values and load position distribution as design variables; and finally, based on optimizing technologies such as an enumeration method, a genetic algorithm and a surrogate model, the most disadvantageous disturbance load of the multiple points that limits the defect amplitude is searched for, and a reduction factor of the bearing capacity of the axial load cylindrical shell structure is determined, so as to establish a more physical method for evaluating the defect sensitivity and the bearing performance of the axial load cylindrical shell structure.