METHOD OF TESTING POLYMER COMPOSITE MATERIALS FOR IMPACT RESISTANCE Russian patent published in 2020 - IPC G01M7/08 G01N3/303 

FIELD: test technology.

SUBSTANCE: invention relates to impact tests and can be used first of all for impact tests of multilayer devices in form of, for example, packs of plates from composite materials and honeycomb panels used in making structural elements of transport vehicles, in particular, aircrafts. Specimen is damaged by impact of a freely falling load with a tip of hemispherical shape, at which all samples irrespective of material, laying scheme and other parameters are subjected to impact with the same energy normalized as to thickness of the sample. Tests are carried out in sequence: sample is fixed in appliance and centered, hammer is released and allowed to freely fall on sample surface, wherein hammer repeated contact with sample after rebound is prevented, force versus time is recorded, depth of impression is measured, and impact damage is evaluated by fingerprint size and is characterized by type of sample damage. Dependence on time and applied contact force is recorded as additional parameters. Simultaneously, damping characteristics of material are determined from recorded period of attenuation and frequency of forced oscillations of material initiated by impact, amplitude of vibration displacement in vertical and horizontal planes, as well as amplitude of vibration acceleration.

EFFECT: possibility of complex quantitative assessment of material resistance to concentrated impact load, taking into account the dimensions and nature of damage area, force and impact time, damping force of impact and forced oscillations due to determination in one test of extended number of sample parameters, allowing to estimate, including loads, transferred by polymer composite material on structures connected to it.

3 cl, 12 dwg