THE INFLUENCE OF DEFECTS ON THE PHYSICO-MECHANICAL PROPERTIES OF POLYMER COMPOSITE MATERIALS AND PRODUCTS

The issues of the formation of physical and mechanical properties in polymer composite materials consisting of reinforcement (glass fiber) and a matrix (resin) are considered. The reasons causing failures in polymer composite materials of the specified type and products based on them are given. The dependence of the average strength and ultimate relative strain of monofilaments on their length and diameter has been studied. The effect of defects on the surface of reinforcing glass fibers on their strength has been studied. It is shown that with an increase in the length of glass fiber, defects of various types are formed on its surface. An empirical formula for the rate of fiberglass cracking is given. It is shown that the second stage of the glass fiber destruction process is poorly described by a power function with a constant exponent when the level of unloading stresses changes. The dependence of the nominal voltage on the actual voltage in glass fibers is obtained for various values of the coefficients of variation. It is shown that the main processes of interaction between the resin and the fiber occur either at their interface or in the border zone.