| The influence of relevant parameters in structural reliability analysis is very important.In traditional reliability analysis,the randomness of related design parameters is often considered only from the point of view of probability theory.However,the uncertainty factors that affect the structural reliability are often not just random.Because of the limitation of people's understanding and the complexity of practical engineering,the fuzziness of relevant parameters of engineering structure is also a very important part of uncertainty,so it is of great practical significance to carry out fuzzy reliability analysis of engineering structure.In this paper,the fuzzy reliability of wharf structural components is analyzed based on the engineering background of an inland river overhead vertical wharf,and the fuzzy reliability of wharf structure system is studied on the basis of it.The main work done in this paper is as follows:(1)Combined with the theory and method of fuzzy mathematics,the standard deviation of statistical parameters of resistance and load effect of wharf structural members is fuzzified,and the theoretical calculation method of structural fuzzy reliability is derived.The fuzzy reliability index of the structure is calculated by using the checking point method.(2)The main contents are as follows:(1)the finite element model of transverse frame arrangement of an inland river overhead vertical wharf is established by using ANSYS software.The wharf loads include wharf weight,wharf surface surcharge,loading and unloading mechanical load and ship impact force as the dominant variable action.The static analysis of the transverse frame structure of wharf is carried out,and the maximum bending moment of the component is extracted.The analysis results show that the stress concentration of the front row pile foundation of the wharf reaches the maximum bending moment at the lowest impact point of the ship.(3)The statistical parameters of resistance and load effect of wharf structural members are analyzed,and the related statistical parameters are transformed from non-standard normal distribution to standard normal distribution.Considering the related influencing factors,the fuzzy state constraint level of resistance and load effect is calculated by analytic hierarchy process(AHP)and fuzzy second-order comprehensive evaluation method.Then the fuzzy reliability index interval of wharf structural components is calculated by MATLAB programming combined with the checking point method.The analysis results show that the reliability index of pile foundation in the front row of wharf is the lowest,and the increase of safety reserve can be considered,while thereliability of column and ship column is too high and the safety reserve is too abundant,which can be optimized to a certain extent from the point of view of economy.(4)Based on the reliability correlation theory of the system and the correlation calculation principle of nonlinear function,the correlation between the main components of the transverse frame of the wharf is calculated.The results show that the cross beam of the wharf is highly correlated with the transverse connecting brace.There is a high correlation between column and pile foundation,and the rest are non-advanced correlation.Then using PNET method,the representative mechanism of wharf structure is selected as crossbeam,transverse connection brace and pile foundation according to the order of reliability from small to large.Thus,the fuzzy system reliability interval of the wharf structure is calculated by using the fuzzy reliability interval of the wharf structural members calculated above.The calculation results show that the fuzzy system reliability of the structure can be roughly estimated by using the fuzzy reliability of the structural components in practical engineering. |
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