Analysis Of Calculation Method For Structural Reliability And Application In Mooring Mechanism

The mooring mechanism is one kind of unique equipment of mooring mine. In fight enlistment period, mooring mine is on mooring state and making the irregular movement due to the influence of ocean current and ocean wave and so on. The mooring mechanism and the environment that the mechanism locates are comparatively complex, which request the mooring mechanism to have comparatively higher reliability. Otherwise once mechanism break, eating-thrown and so on fatal breakdown happen to the mooring mechanism, mooring mine would lose its function and cut short fight enlistment period, which will pose the enormous threat to the military deployment and the national security of our country. Main content of this thesis is as following:1 The article summarizes the computation step of four kinds of methods forstructural reliability calculation such as mean point method, design point method, Monte-Carlo simulation and importance sampling method and compared computation precision and efficiency of the methods. An opinion to improve the computation precision of design point method is put forward in the article. The calculating methods of failure degree of one failure mode and multi-failure modes of series or parallel in non-probabilistic set are proposed by adopting Monte-Carlo Method.2 The structural style and stress environment of the mooring mechanism are analyzed and as also as the force and moment in the environment. Different movement posture and friction forms of the mooring mechanism are calculated and analyzed in complex environment. The structural reliability of the mooring mechanism system and its weak parts such as mooring cingulum, aluminum bolt M6, mooring axletree, easy-break pin and ABS material are calculated by mean point method, design point method, Monte-Carlo simulation, importance sampling method and adopting calculating method of failure degree of multi-failure modes of series or parallel in non-probabilistic set.3 The calculating software for structural reliability analysis and calculation of the mooring mechanism part in mooring mine is used of Fortran,Visual Basic. While Fortran is used to reliability calculation, Visual Basic is used to human-computer interface design. Four kinds of methods for structural reliability analysis such as mean point method, design point method, Monte-Carlo simulation and importance sampling method are used to calculate reliability for weak part of the mooring mechanism, and variables in every method use five random distribution such as normal random distribution, logarithmic normal distribution, uniform distribution, Weibull distribution and extreme value distribution, that can satisfy designers' request to structural reliability analysis and calculation of the mooring mechanism part in mooring mine.