Loose cable net form-finding method based on catenary element

Abstract

The invention provides a loose cable net form-finding method based on a catenary element. The loose cable net form-finding method mainly includes the steps: selecting material parameters D, geometrical parameters S, topological structures and boundary node positions Pfix of a cable net; setting an initial position Pfree of a middle free node of the cable net; building a catenary loose cable net model under the action of gravity; calculating cable segment forms and node force in a cable net system; analyzing resultant force of nodes of the cable net; judging whether resultant force of an optional node meets requirements or not, and outputting results if the resultant force meets the requirements; continuing to set the initial position Pfree of the middle free node of the cable net if not; finally, outputting the balance position of the middle free node of the cable net. Form-finding analysis for the loose cable net is realized by a nonlinear finite element method, the results are matched with a force density method, stiffness information of the loose cable net in any configuration is acquired, dynamic performances of the loose cable net can be further analyzed, or the loose cable net is combined with other finite elements (such as rods, beams, plates and shells) to realize modeling, and kinetic analysis of complicated structures is performed.

Description

technical field [0001] The invention belongs to the technical field of cable net form-finding, in particular to a form-finding method for a relaxed cable net based on a catenary unit. Background technique [0002] Cable-net systems are used as supporting structures in many fields, such as roofs of large lightweight buildings, bridges, fishing nets and deployable antennas with mesh reflectors, and the design process plays a vital role. However, in the cable-net system, the cable is a flexible structure with the characteristics of large displacement, small strain, and highly nonlinear geometry, and its initial configuration is not clear. Net form-finding problem. [0003] In the past, linear rod elements were mostly used for cable-net modeling and form-finding analysis. For tensioned cable-net systems, there are relatively mature methods for initial form-finding analysis, such as nonlinear finite element method and dynamic relaxation method. and force density method, etc.; f...

AI Technical Summary

Problems solved by technology

[0004] At present, there is a form-finding method for a relaxed cable network that uses a catenary element described by a vector and a force density method, but it cannot obtain information such as the mass matrix and stiffness matrix of the cable network.

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