RELIABILITY ANALYSIS OF PLANAR PRESTRESSED STEEL TRUSSES BASED UPON REFLECTION TRANSFORMATION METHOD

The method of reflection transformation is used to establish the computational model of reliability index of each element of planar prestressed steel structures with elastic restraint,and reliability index of the structural system is further obtained with the method of point evalution technique.Random parameters,including areas of cross sections of all the elements,area of cables,pretension of cables,external forces and stiffness of elastic restraint are considered.Finally,some computational examples are put forward and the results are discussed.It is concluded that effect of mean square deviation of pretension of the cables,on reliability index of the structures is relevant to characteristics of distribution of random variables,and the effect of the random variables being in normal distribution is commonly less than that in logarithmic normal distribution.On the other hand, effect of mean square deviation of random variables on reliability index of the structures is also linked to relativity coefficient -(NA),which lay some fundation for reliability design of the prestressed steel structural system.