Methods for Research of Joints with Composite Materials

Abstract

This scientific paper deals with the analysis of various non-destructive testing methods in order to justify their application as the tool for investigating the strength of adhesive joints in composite materials. Strength characteristics are given for the press-fit joints with composites having poorly studied adhesive properties. A number of test experiments is carried out by destructive and non-destructive methods; the stressed state of the joint area and its adjacent areas is assessed. Necessary properties of the adhesive joint depend on the variety of factors, one of them is the interaction with specific areas of the adhesive surfaces, the other one is the average value of contact pressure that is required for the maximum contact of surfaces. Independently on the design parameters (clearance joint or press-fit joint), the assembly method provides for the guaranteed filling of the space between contacting parts by the composite material supplied into the contact zone by various methods. In order to provide the further application of joints, it is necessary to establish the interaction between the strength that is determined experimentally and readings of devices at non-destructive testing. Such an approach will allow for extending the application area of both adhesive joints and joints with the layer of nano-structurized composite. The assembly of joints can be carried out at a relative shift of the parts to be assembled under liquid friction provided by the adhesive composite. The method for controlling the adhesive press-fit joints with the composite layer which is optimal from the practical point of view has been chosen. The advantage of the method for introducing the ferroelectric additives into the adhesive layer is shown when assessing the strength characteristics of adhesive joints at application of the acoustic electromagnetic method.