Sensitivity Analysis of Geometrical Imperfections in Aerospace Structures Research and Design

Format:

Book

Conference/Event

Author/Creator:

Sharma, Amit, author.

Singh, Nishant, author.

Xavier, Shijo, author.

R, Suresh, author.

Conference Name:

AeroCON 2026 (2026-06-04 : Bangalore, India)

Language:

English

Subjects (All):

Finite element analysis.

Launch vehicles.

Hardware.

Aircraft structures.

Local Subjects:

Finite element analysis.

Launch vehicles.

Hardware.

Aircraft structures.

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2026

Summary:

Launch vehicle structures are designed to withstand flight loads while fulfilling their intended functional requirements. Most of these structures use cylindrical geometries and employ stiffened configurationssuch as isogrid, orthogrid, or skin-stiffened designscomprising multiple long panels to efficiently carry dominant compressive loads. Traditional FE analyses generally use simplified or idealized imperfection models, which often do not represent the imperfections present in actual hardware and therefore tend to over/under-predict load-carrying capacity based on the initial assumed imperfection level. In reality, long stiffened panels are highly sensitive to geometric imperfections introduced during manufacturing. These include spring-back effects from roll bending as well as deviations accumulated during assembly. Such manufacturing-induced variations can significantly diminish the effective load-bearing capability of the structure.The subject hardwarean isogrid cylindrical structure was designed and hardware realized. In order to study the effect of imperfection hardware with maximum deviation was inspected with laser taker CMM. The typical isogrid cylindrical structure comprising multiple panels joined with splicer plates, fore end and aft end rings Imperfection are inspected for end-ring ovality and profile deviations along the shell. The as-built geometric profile, captured using a laser tracker CMM, was mapped directly onto the FE model to accurately represent real-world imperfections. A nonlinear analysis was carried out for three cases i.e ideal, Eigen mode-imperfect geometry and fabricated geometry to evaluate the critical buckling load capacity.This paper presents a methodology for cylindrical structure with isogrid stiffening scheme, by incorporating manufacturing-induced deviations into the finite element model. The approach enables realistic structural integrity assessments thus reducing the uncertainties inherent in traditional analysis techniques

Notes:

Vendor supplied data

Access Restriction:

Restricted for use by site license