A non-probabilistic reliability shape optimization design method for trusses

Abstract

The invention discloses a method for optimally designing non-probabilistic reliability shapes of trusses. The method includes steps of firstly, determining design variables of the to-be-optimized trusses; secondly, determining structure capability functions; thirdly, acquiring non-probabilistic reliability index functions eta (X, A, P) corresponding to the structure capability functions g (X, A, P); fourthly, carrying out non-dimension processing on the design variables; fifthly, building truss non-probabilistic reliability shape optimization models; sixthly, solving the truss non-probabilistic reliability shape optimization models. The method has the advantages that rod coordinates and the sectional areas of rod pieces are used as the design variables, the non-dimension unified processing is carried out on the design variables, Tailor's approximation is carried out on the capability functions at interval midpoints instead of the traditional design points, the interval midpointsare found out in advance, and accordingly the shortcomings of the traditional reliability constraint optimization iteration procedures can be overcome by the aid of the method; the traditional nestedtwo-level optimization models are converted into a single-level model, accordingly, the problem of difficulty in convergence by the aid of optimization algorithms due to wide coupling and variation ranges of different types of variables can be solved by the aid of the method, and the reliability shapes of truss structures can be optimized by the aid of the method.

Description

Technical field [0001] The invention belongs to the technical field of truss non-probabilistic reliability optimization, and specifically relates to a truss non-probabilistic reliability shape optimization design method. Background technique [0002] The truss is a lattice system composed of several straight rods connected by hinges at both ends. The rods in the truss mainly bear axial tension and pressure, and the stress distribution on the cross section of the rods is relatively uniform, which can make full use of the role of materials, save materials, and reduce structural weight. Therefore, truss is a commonly used form of large-span structures. It is widely used in aviation, construction, machinery, bridges and civil engineering. In the actual truss design and manufacturing, due to the influence of many factors, there are many uncertainties related to the geometric dimensions, physical parameters, loads and boundary conditions of the truss structure. The combination of the...

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Problems solved by technology

In the above size optimization and topology optimization techniques, since the process of determining the non-probabilistic reliability index function is also an optimization design problem, the actual structural optimization problem is a two-level mutual coupling optimization problem, which greatly affects the structural optimization. efficiency

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