A complex structure has many uncertain factors and how to make a more accurate analysis on the structure reliability by a method is the key in engineering calculation. Rough
Keywords: Structure reliability index; Evaluation; Engineering cost; Rough set theory; Rough variables; Intelligent algorithmCopyright © 2016 Universitas Ahmad Dahlan. All rights reserved.
IntroductionAs defined in unified standard [1] for design of structure reliability index, structure reliability index is the capacity of the structure to complete predetermined functions in specified time and specified condition and the corresponding probability is degree of reliability. Specified time means the designed service life namely the time that the structure or the member can be used for predetermined purpose without overhaul. Specified condition means "three normal", namely normal design, normal construction and normal predetermined function use which means security, applicability and durability.Traditional reliability calculation method based on probability theory and mathematical statistics is called probability reliability calculation method and is also called conventional reliability calculation method. Common structure reliability calculation method includes firstorder second-moment method, high-order high-moment method, optimization method, response surface method, Monte Carlo method and random finite element method.There are many uncertain factors in all kinds of engineering structures, such as physical property, geometrical parameters and carried load (such as wind load, wave load and seismic load etc.). People fail to determine the value of them in advance and influence of uncertain factors on structure becomes more and more serious due to the limitation of conditions. Traditional uncertain information processing method includes fuzzy set theory, evidence theory and probability statistics theory etc.Literature research [2,3] indicates that, probability reliability calculation method is sensitive to the probability model parameters and small error of probability data may lead to a bigger error of structure reliability calculation, so probability reliability theory faces a huge challenge. Therefore, the Thesis uses rough set theory to calculate the structure reliability index and to simulate the uncertainty of the structure to describe the uncertain parameters of the structure into rough variables and uses the maximum uncertainty degree allowed by the structure to measure the reliability so as to obtain the reliability index of the structure and this method is accurate both in the variable expression and calculation result.