776 results about "Mechanics model" patented technology

The invention provides a system and method for determining nonlinear membrane stress. According to the invention, a membrane material is taken as a multilayer board shell structure to perform mechanic modeling so as to define the deflexion, cross section corner, middle plane internal displacement or curvature variation on the middle plane of the multilayer board shell structure as well as nonlinear geometric relationship to describe the deformation of the membrane material. Shape measuring equipment is adopted to measure the deformation of the membrane material caused by membrane stress, and the deformation is represented as the deflexion, cross section slope, middle plane internal displacement or curvature variation of the thin-film material. The finite elements of the multilayer board shell structure are adopted to discrete the geometrical model of a detected object, the measured values of degree of freedom of all or part of finite element nodes are given in a direct measurement or indirect interpolation manner, the least square fitting condition between the deformation generated by membrane stress at the nodes and the measured deformation is created, and the membrane stress is reversely solved through nonlinear iterative computations. As for membrane temperature mismatching stress belonging to part of the membrane stress, the nonlinear temperature mismatching stress of the membrane material with a deformed base body is calculated and considered at the same time under the condition of given temperature variation.