FIELD: investigation of strength properties of composite materials. SUBSTANCE: process of strength testing of composite materials with cross laying of reinforcing fibers consists in tensile loading of specimen up to destruction, in uninterrupted measurement of load and deformation of specimen and in determination of time resistance of material to tension by computation method. First profiles of triangular shape with rounding radius of vertex equal to 0.25-1.0 mm and sides parallel to direction of laying of reinforcing fibers are formed in symmetry with longitudinal axis of specimen and ratio of widths of working part of specimen in profiled and non-profiled zones is not more than 0.1-0.2. Then at least two small-base resistance strain gauges are cemented on to vertexes of profiled zone of specimen on two sides. Specimen is first loaded to 30-50% value of anticipated breaking load and non-uniformity of distribution of stress across section of specimen in profiled zone of working part of specimen is controlled by readings of resistance strain gauges, non-uniformity is corrected by displacement of point of application of resultant load and later specimen is loaded continuously with specified rate of deformation of material to its destruction. EFFECT: raised accuracy of testing, generation of authentic data on strength characteristics of composite materials with cross laying of reinforcing fibers in wide range of temperatures. 3 dwg
