Method of evaluation of the probabilistic dispersion of traction and transport vehicles estimated noisiness

This paper describes questions, which are connected with possibility of obtaining the dispersion of traction and transport vehicles (TTV) noisiness computation on the stage of its development. Experimental data shows that noise around TTV and at operator workplace has wide dispersion of values for even one model produced by one factory at the same time. It concerns practically every type of TTV – new and with some operating time, at mass, individual and serial producing, and at similar operation conditions. Mathematical functions for determination of dispersion mentioned above in dependence on confidence interval of various sources noisiness were obtained. The general method for assessment of probabilistic dispersion of estimated noisiness results is presented. This general method for probabilistic dispersion of computational evaluation of TTV noisiness consists of next stages: assessment of dispersion (confident interval) of acoustic power of each separate noise source; determination of computational function (choice or compiling formulas for computation); determination of dispersion (confident interval) for sound absorption coefficients and other independent variables; determination of partial derivatives for computational function on each independent variable; obtaining of functional dependence of result dispersion of input factors (arguments); calculating of numerical assessment value of TTV noisiness determination result.