Is it possible to improve strength of a hollow cylinder against radial load by making holes in it or converting it into scaffolding like structure without changing material, internal dia, external dia and length?
2 Answers
Generally speaking, the strength of a structure for a static load cannot be improved by removing material. Usually material is removed in low-stress regions to improve the strength-to-weight ratio, but that does not improve the overall strength of the structure.
Some cases where removing material could help improve strength would be in rounding a sharp edge to remove a stress concentration, or reducing the mass of a part to make it less susceptible to dynamic loads of a certain frequency (by changing its resonant frequencies).
Use thicker wall perforated cylinders and add hoop/bulkhead rings or helical reinforcements. They increase radial resistance against tendency to buckle (as in underground gas tanks). A slight curving like hypar also would help but at a cost.