Reliability Analysis Of Beam String Structures Based On Response Surface Method With Double-Weighted Regression

As a new type of large-span prestretching steel structure system, the beam string structure (BSS) has the advantages of simple structure, explicitnessm of force transferring, convenient construction, perfect architectural modeling and structural arrangement and has a broad application in practical engineering. Actually, there are a large number of uncertainties in the design, construction and application of the BSS and it is therefore necessary to study the reliability of the BSS.In this thesis, a program for the form finding of the BSS is compiled with the APDL language used in ANSYS parametric design. The form finding process is analyzed by combining an example of a single frame BSS and the effect of the initial prestretching of cables on the structure is discussed. The linear and nonlinear buckling of a single frame BSS is performed with a single frame BSS.In the response surface method, the polynomial with unknown coefficients is replaced with the implicit limit state function and where the structural response is computed from the finit element method, A new response surface method is presented in this thesis based on the double-weighted regression, in which less computational time is required and more realistic numerical results are achieved.The reliability calculation of the BSS is conducted with the proposed method. The numerical results show that in the four possible failure modes, the failure probability owing to insufficient strength is the lowest whereas that owing to displacement control is the highest. reliability of stability under half span load is a litter higher than under full span.Finally, with each possible failure modes considered as a series system,through correlation coefficient matrix, a probability-weighing approach method for calculating the reliability of structural system.