PSI - Issue 31

M. Dundović et al. / Procedia Structural Integrity 31 (2021) 111 – 115

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M. Dundovi ć et al. / Structural Integrity Procedia 00 (2019) 000–000

Fig. 2. Measurement method.

The edge isochrome order determined by linear extrapolation was N edge = 3,79. Finally, the constant was determined to be f σ = 25,96 N/mm. After defining the photoelastic constant, the appropriate isochrome order was determined for each loading condition to determine the stress-strain relation. The result of the measurements was validated by numerical FEM using beam elements having 3 nodes and 6 degrees of freedom in each node. The results of the numerical analysis are also shown in Fig. 3. It can be concluded that the experimental results are in good concordance with the results of numerical analysis.

Fig. 3. Comparison of photoelastic testing results with FEM analysis for vertical specimen.

4. Conclusion Developments in additive technologies have made the fabrication of photoelastic models more available and less time consuming. The experimental investigation carried out in this paper demonstrates that DLP manufactured specimens are suitable as models to be used in two-dimensional photoelastic research. The observed isochromatic fringe patterns were in good agreement with numerically obtained results. It can be concluded that DLP manufactured specimens are a viable basis for the validation of finite element solutions for any design problem. Further research will be carried out with variation of printing process parameters and post curing exposure time with the goal of obtain different material behavior for validation of different material models. Acknowledgements This work has been supported by Croatian Science Foundation under the project number IP-2019-04-3607 and by University of Rijeka under projects number uniri-tehnic-18-34 and uniri-pr-tehnic-19-21.