ACCURACY OF STATISTICAL CALCULATION OF RANDOM ERRORS OF SPACE TRUSSES

Probabilistic treatment of the deviation of real dimensions of bar elements from their nominal values leading to the errors in geometry of structures is presented in the paper. It is noticed that the distribution of errors in framed structures is of normal character.The main principles of statistical modelling of the real form of a space truss and estimation of errors are discussed, and the arguments presented for using the standard deviation as the primary statistical parameter of errors. It is demonstrated that the accuracy of calculation of standard deviations of errors must be accounted for in engineering problems. Based on the numerical values of the chi-square distribution the dependence is obtained between the accuracy of the standard deviation and the sample size for different levels of reliability