- freely available
Materials 2019, 12(22), 3699; https://doi.org/10.3390/ma12223699
2. Theoretical Basis
3. The Object of the Study
4. Experimental Test Stand
5. Numerical Modelling
5.1. Material Modeling
5.2. Boundary Conditions
5.3. Mesh and Elements
6.1. Comparison of FE Results and the Experiment for the Stiffened Plate
6.2. Comparison of FE Results for Stiffened and Smooth Plates
- Introduction of triangularly arranged ribs increased the critical load by 300% in comparison to the smooth plate with equivalent mass. This phenomenon can be used in situations where it is intentional to maintain the shape of the structure (e.g., impact on aerodynamics), or directly when the local loss of stability is not permissible and critical load is equal to limit load.
- Comparisons of post-critical behaviours of the investigated structures proved that in the range of elastic deformation, the stiffened plate may have significantly better properties in the case of deflection and stress level, without an increase in the mass of the structure.
- Use of integral triangular stiffening in the design of thin-walled elements made it also possible to reduce the mass of the load-bearing structures maintaining the critical and limit load. This issue will be the subject of further work.
- Despite the use of certain simplifications covering both the geometry of the structure and the material model in the FEM analyses, it should be noted that results with a satisfactory degree of convergence were obtained.
- Reduced properties of the stiffened plate in the range of the plastic deformations are related to the stress concentrations. Such effects are probably caused by the incorrect geometry of the rib pattern around the corners of the plate, resulting in changes to the rigidity of the structure in the areas under consideration. More research should be carried out to obtain the methodology of the correct selection of geometry near the attachment areas. This fact should be taken into consideration when designing real construction solutions.
- Considering the occurrence of significant stress concentrations, it is necessary to carry out fatigue tests that will prove the impact of introducing the isosceles grid pattern of low-profile, integral ribs on the service life of the structure.
Conflicts of Interest
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|Parameter Name||Young’s Modulus E, GPa||Poisson Ratio||Ultimate Tensile Stress Rm, MPa||Yield Stress Rp0.2, MPa|
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