Issue 41

E. Nurullaev et alii, Frattura ed Integrità Strutturale, 41 (2017) 369-377; DOI: 10.3221/IGF-ESIS.41.48 372 dispersed ingredients in the polymer composition for corresponding characteristics set, for example mechanical, γ j are densities of dispersed components, I n is variety of indexes for filler types being part of polymer material formulation. Because of the difficulty, given problem which includes limitation of equation types is converted into the nonlinear programming problem with limitation of in equation types. At that quantity of optimizable independent variables is n = ( m j ) - m , where m is quantity of polymer material solids types. Normalizing ratio:           1 1 m j opt jv j j I j I n n v is automatically fulfilled in case of problem solution. Then we determine the vector of optimum volume fractions for filler fraction in the composition:         ( ; ); 1, 2, 3, ..., , opt opt I v m jv j n j where  opt jv is optimum volume fraction of v -th fraction for j -type filler. Transformation to optimum mass concentrations of the corresponding solids       ( ; ; 1, 2, 3, ..., ) opt opt x x I v m j jv j n j is carried out by formula:       ( ) / ( / ) , opt opt opt x P jv jv j j j where         1 m j opt opt P x x jv j j I j I n n v is the sum of mass concentrations (ratios) of polymer material solids. Mechanical fracture energy ( W ) of PCM depending on rupturing elongation degree (α b ) is calculated by formula [11]:   2 3 3 2 1 3 3 2 2 3 1 2 3 1 1 1.25 29exp 0/225 10 2 1 2 2 b m b b b W RT T T a g ch r m b b                                                                    (1) Mathematical problem statement for maximum fracture energy search when limitations of other characteristics are fulfilled can be described as following nonlinear programming problem:                                                  , , - max 5 5 0.110 2 10 0.3 1 0.7 0.5 1 W ch r m ch i I i n r sw i m i (2) where:     , , ch r m – vectors of cross-linking mole concentration, polymer volume fraction in the binder and effective extent of volume filling, respectively; φ sw – plasticizer volume fraction, coherent with polymer volume fraction ( φ m ) as ratio     ( ) 1 r sw ; I n – variety of indexes for composition; n –quantity of composition calculation types.