Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness Ratios

This study is aimed at providing a numerical derivation of the shell knockdown factors of isogrid-stiffened cylinders under axial compressive loads. The present work uses two different analysis models such as the detailed model with modeling of numerous stiffeners and the equivalent model without mo...

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Main Authors: Han-Il Kim, Chang-Hoon Sim, Jae-Sang Park, Keejoo Lee, Joon-Tae Yoo, Young-Ha Yoon
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:International Journal of Aerospace Engineering
Online Access:http://dx.doi.org/10.1155/2020/9851984
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author Han-Il Kim
Chang-Hoon Sim
Jae-Sang Park
Keejoo Lee
Joon-Tae Yoo
Young-Ha Yoon
author_facet Han-Il Kim
Chang-Hoon Sim
Jae-Sang Park
Keejoo Lee
Joon-Tae Yoo
Young-Ha Yoon
author_sort Han-Il Kim
collection DOAJ
description This study is aimed at providing a numerical derivation of the shell knockdown factors of isogrid-stiffened cylinders under axial compressive loads. The present work uses two different analysis models such as the detailed model with modeling of numerous stiffeners and the equivalent model without modeling of stiffeners for isogrid-stiffened cylinders. The single perturbation load approach is used to represent the geometrically initial imperfection of the cylinder. Postbuckling analyses using the displacement control method are conducted to calculate the global buckling loads of a cylinder. The shell knockdown factor is numerically derived using the obtained global buckling loads without and with the initial imperfection of the isogrid-stiffened cylinder. The equivalent model is more efficient than the detailed model in terms of modeling time and computation time. The present knockdown factor function in terms of the shell thickness ratio (radius to thickness) for the isogrid-stiffened cylinder is significantly higher than NASA’s knockdown factor function; therefore, it is believed that the present knockdown factor function can facilitate in developing lightweight launch vehicle structures using isogrid-stiffened cylinders.
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institution Kabale University
issn 1687-5966
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language English
publishDate 2020-01-01
publisher Wiley
record_format Article
series International Journal of Aerospace Engineering
spelling doaj-art-c7ec2cac04a44bbda453d46a5b0f30062025-08-20T03:24:11ZengWileyInternational Journal of Aerospace Engineering1687-59661687-59742020-01-01202010.1155/2020/98519849851984Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness RatiosHan-Il Kim0Chang-Hoon Sim1Jae-Sang Park2Keejoo Lee3Joon-Tae Yoo4Young-Ha Yoon5Department of Aerospace Engineering, Chungnam National University, Daejeon 34134, Republic of KoreaDepartment of Aerospace Engineering, Chungnam National University, Daejeon 34134, Republic of KoreaDepartment of Aerospace Engineering, Chungnam National University, Daejeon 34134, Republic of KoreaSmall Launcher Team, Future Launcher R&D Program Office, Korea Aerospace Research Institute, Daejeon 34133, Republic of KoreaLauncher Structures and Materials Team, Korea Aerospace Research Institute, Daejeon 34133, Republic of KoreaLauncher Structures and Materials Team, Korea Aerospace Research Institute, Daejeon 34133, Republic of KoreaThis study is aimed at providing a numerical derivation of the shell knockdown factors of isogrid-stiffened cylinders under axial compressive loads. The present work uses two different analysis models such as the detailed model with modeling of numerous stiffeners and the equivalent model without modeling of stiffeners for isogrid-stiffened cylinders. The single perturbation load approach is used to represent the geometrically initial imperfection of the cylinder. Postbuckling analyses using the displacement control method are conducted to calculate the global buckling loads of a cylinder. The shell knockdown factor is numerically derived using the obtained global buckling loads without and with the initial imperfection of the isogrid-stiffened cylinder. The equivalent model is more efficient than the detailed model in terms of modeling time and computation time. The present knockdown factor function in terms of the shell thickness ratio (radius to thickness) for the isogrid-stiffened cylinder is significantly higher than NASA’s knockdown factor function; therefore, it is believed that the present knockdown factor function can facilitate in developing lightweight launch vehicle structures using isogrid-stiffened cylinders.http://dx.doi.org/10.1155/2020/9851984
spellingShingle Han-Il Kim
Chang-Hoon Sim
Jae-Sang Park
Keejoo Lee
Joon-Tae Yoo
Young-Ha Yoon
Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness Ratios
International Journal of Aerospace Engineering
title Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness Ratios
title_full Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness Ratios
title_fullStr Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness Ratios
title_full_unstemmed Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness Ratios
title_short Numerical Derivation of Buckling Knockdown Factors for Isogrid-Stiffened Cylinders with Various Shell Thickness Ratios
title_sort numerical derivation of buckling knockdown factors for isogrid stiffened cylinders with various shell thickness ratios
url http://dx.doi.org/10.1155/2020/9851984
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AT joontaeyoo numericalderivationofbucklingknockdownfactorsforisogridstiffenedcylinderswithvariousshellthicknessratios
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