Abstract
A rapid semi-analytical model is developed based on the Ritz energy method for the buckling analysis of variable stiffness (VS) sandwich panels. VS is introduced into the structure by allowing the fibre angle of the composite face-sheets to continuously vary in the transverse direction and transverse shear effects are included with a first-order-shear deformation theory with additional shape functions for shear strains. The model is shown to be in good agreement with a commercial finite element package whilst requiring less degrees of freedom. A parametric study revealed that VS sandwich panels with high shear modulus cores, above a threshold value, can achieve similar gains in buckling performance to that observed with thin VS plates. However, below this threshold value, core shear crimping modes can become critical in highly loaded local regions, due to pre-buckling load redistributions, resulting in significantly reduced performance gains compared to straight fibre panels. Results from an optimisation case study show that panels with a core shear stiffness above the threshold required to prevent crimping, can achieve improvements up to 78 % compared to straight fibre panels. However, with reducing core shear modulus below the threshold value, the improvement reduces to less than 1 % with shear crimping modes dominating.
| Original language | English |
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| Publication status | Published - 2015 |
| Externally published | Yes |
| Event | 20th International Conference on Composite Materials, ICCM 2015 - Copenhagen, Denmark Duration: 19 Jul 2015 → 24 Jul 2015 |
Conference
| Conference | 20th International Conference on Composite Materials, ICCM 2015 |
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| Country/Territory | Denmark |
| City | Copenhagen |
| Period | 19/07/15 → 24/07/15 |
Keywords
- Crimping
- Ritz method
- Transverse shear
- Variable angle tow