PSI - Issue 33

Tatyana Tretyakova et al. / Procedia Structural Integrity 33 (2021) 1013–1018 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Mechanical tests were carried out on a ‘Instron 8850’ biaxial servo-hydraulic testing system (axial load in the range of ± 100 kN, load measurement error no more than 0.5%), see Fig. 2. The registration of forces and displacements was carried out using the built-in sensors of the test system, the use of mounted extensometers in this case is difficult due to the short length of the working part of the samples.

Fig. 2. Photo of a sample in the process of testing for uniaxial tension (left) and a photograph of axisymmetric samples with annular concentrators of various geometries (right)

3. Numerical calculations of the stress-strain state of specimens with ring concentrators of various geometries Numerical calculations of the stress-strain state of samples are implemented in the Ansys 18 software package. The solution of the problem is carried out in an axisymmetric formulation using a four-node finite element Plane 182. The geometry of the computational domain (1/4 of the central plane) and boundary conditions are shown in Fig. 3. Material properties are taken isotropic: Young's modulus E = 71ꞏ10 9 Pa, Poisson's ratio υ = 0.3. As a result of the solution, diagrams of the distribution of the main stresses were plotted for samples with concentrators in the form of annular grooves of various geometries, which are shown in Fig. 4. At the qualitative level, the obtained dependences do not contradict the data available in the literature.

Fig. 3. Image of geometry and boundary conditions in the considered area.