Numerical study on influence of dent parameters on critical buckling pressure of thin cylindrical shell subjected to uniform lateral pressure

• For constant dimensions of a dent, as the angle of orientation of dent (q) increases from 0°-90° the BSR (Buckling Strength Ratio) decreases, with higher BSR for circumferential dent and lower BSR for longitudinal dent.
• Dent Length (DL) variation of circumferential dent has insignificant effect on BSR, whereas the longitudinal dent has considerable effect on BSR for DL variation. In case of circumferential dent, as Dent Width (DW) increases, BSR decreases. But, in case of longitudinal dent as DW increases, BSR increases. These effects are more pronounced at higher shell thickness and lower L/R ratio. In Dent Depth variation, both circumferential and longitudinal dents have almost same effect on BSR.
• Smaller dent does not have influence for both dent parameters and θ.

One of the common failure modes of thin cylindrical shells subjected to external pressure is buckling. The critical buckling pressures of these shell structures are mainly affected by the geometrical imperfections present in the cylindrical shell which are very difficult to alleviate during manufacturing process. Dent is one of the common geometrical imperfections present in thin shell structures which may be formed due to mechanical damage caused by accidental loading or impact. In this work, numerical parametric study is carried out to study the influence of dent parameters of centrally located dent (dent length, dent width, dent depth and angle of orientation of the dent), cylindrical shell parameters (L/R ratio and R/t ratio) and yield stress on the critical buckling pressure of externally pressurized thin dented cylindrical shells with simply supported boundary conditions at both top and bottom edges using non-linear static finite-element analysis of ANSYS.