Reliability Analysis of Structure System Considering Failure Modes of Strength, Fatigue and Buckling

Abstract:

There could be multi-failure modes in the course of working of the structure system including slender bar members. For example, strength failure, fatigue failure and buckling failure, especially sudden buckling failure would bring large disaster to structure. In this paper, according to Fatigue and Damage Mechanics theory, safe margin expression of the different failure mode of structure (static strength, fatigue and buckling) is given firstly, then by analyzing different failure mode of structural element under static and fatigue loads, and failure mode of the calculating element is confirmed by comparing the failure probability value of different failure mode. In the course of searching for significant failure paths, not only is failure mode that stiffness matrix of structure is zero considered, but also buckling failure mode of compressed residual structure is considered too, so that failure analysis is more reasonable. In the end, the reliability calculating method of the structural system is given, and the validity of the method proposed in this paper is explained combining an example.

• Periodical: Key Engineering Materials (Volumes 385-387)
• Pages: 257-260
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.385-387.257
• Online since: July 2008
• Authors: Wei Guang An, Hai An, Yong Yi Zhang
• Keywords: Buckling Failure, Reliability Calculating of System Overall Instability, Residual Resistance, Section Modulus

References

[4] The design life is 15DT = years. Result: Significant failure paths and reliability index of structural system are shown in table 1. Tab. 1 Significant failure paths and reliability index of structural system Summary As can be seen from example: 1) Reliability index (4. 298) of the fifth failure mode which considers buckling failure of structural system is smaller than reliability index (5. 107) of the seventh failure mode which only considers structure turning to mechanism ( 0 i K = ) instead of considering buckling failure, it is shown that the fifth failure mode is more dangerous than the seventh failure mode. So, it is important to consider structure buckling failure; 2) reliability index (3. 557) of considering residual structural integrity buckling is smaller than reliability index (3. 625) of not considering residual structural integrity buckling, this is shown that reliability demands of structural system may not be satisfied if effect of residual structural integrity buckling is neglect. In another word, only by considering synthetically static strength failure, fatigue failure and buckling failure of structural system, the results calculated can be reliable and in accordance with actual engineering design. References.

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[2] Hu Yu-ren, Chen Bo-zhen. Reliability analysis of ship and ocean engineering structure. Beijing: Demotic Traffic Press(1996).

[3] An Wei-guang, Cai Yin-lin, Chen Wei-dong. Reliability analysis and optimum design for stochastic structure systems. Harbin: Harbin Engineering University Press(2005).

[4] Gu Yong-wei, An Wei-guang, An Hai. Structural Reliability Analysis under Static Load and Fatigue Load. ACTA ARMAMENTARII, 2007, 28(12): 1473-1477 P Number of failure modes Failure paths Reliability index of failure modes iβ.

[1] ~.

[7] 1− 3. 685.

[2] ~.

[7] 12 systembuckling − − 3. 843.

[3] ~.

[6] 7 2− − 3. 972.

[4] ~ ~.

[6] 10 2− − 4. 007.

[5] 7 3 systembuckling − − 4. 298.

[6] ~ ~.

[6] 3 2− − 4. 733.

[7] ~.

[7] 3 16− − 5. 017.

[8] ~ ~.

[6] 3 7 2− − − 5. 273 Reliability index of system considering residual structural integrity buckling 3. 557 Reliability index of system not considering residual structural integrity buckling 3. 625 GS QS.

[1] [2] [3] [4] [5] [6] [7] [8] 9.

[10] [11] 12.

[13] [14] 15 l Fig. 1 the plane truss structure Note: Superscript－, ~ and = denotes static strength failure, fatigue failure and buckling failure respectively.