Structural Analysis of Silo 1152A17
Structural Analysis of silo 1152 A17
As part of the commissioning of the 1152A17 silo, SCHWARTZ-HAUTMONT required technical assistance from DYNAMIS ASSOCIATES to carry out structural analyses using the following load configurations:
- Silo in horizontal position submitted to its own weight (transport and assembly position).
- Silo full of water to test for possible leaks (usually known as hydraulic test)
The silo is a cylindrical structure with 33.5 meters height, 7.32 meters diameter. The dome is in the shape of a hemisphere.
To carry out the analyses, a finite element model was built using ANSYS software. This model was used to perform a deep numerical analysis of the structural behavior of the silo under eccentric charge focusing on nonlinear buckling. Effects like geometric nonlinearity, imperfection sensitivity, material nonlinearity, change of silo aspect ratio and variations geometries were considered. Very high compression may cause a buckle adjacent to the edge of the support.
The analyses were carried out in an iterative manner. An initial set of support conditions were established, and the tensional analysis and displacement of the structure were checked to meet the design criteria, particularly determining the absence of buckling of the sheet. At this point, the following sequence of steps would occur:
- If the design conditions are satisfied, this support configuration is chosen as the final solution.
- If the design conditions are not satisfied, the model is modified adding equidistant supports until the design criteria are met.
The main purpose of the study was to define the minimum number of supports for the silo to meet the design criteria under the two load configurations.
The purpose of the study was to define the number of supports necessary for each of the two scenarios (transportation of the silo and hydraulic load test) keeping the integrity of the silo. In particular the local buckling of the plates was verified.