Influence of local stiffeners and cutout shapes on the vibration and stability characteristics of quasi-isotropic laminates under hygro-thermo-mechanical loadings  

作　　者：T.Rajanna K.S.Subash Chandra K.Venkata Rao 

机构地区：[1]Department of Civil Engineering,B.M.S College of Engineering,Bengaluru,560019,India [2]Research Scholar,B.M.S College of Engineering,Bengaluru,560019,India [3]Department of Mechanical Engineering,B.M.S Evening College of Engineering,Bengaluru,560019,India [4]Department of Mechanical Engineering,Government Polytechnic,Bagepalli,561207,India

出　　处：《Defence Technology（防务技术）》2022年第12期2107-2124,共18页Defence Technology

摘　　要：The perforated stiffened panel is generally found as a sub-component of sophisticated structures.The fundamental purpose of this panel is to withstand against buckling under complicated loading and environmental conditions.Hence,an accurate knowledge of critical buckling behaviour of stiffened panels is very much essential for a reliable and lightweight structural design.In this paper,the focus is on quasi-laminated panels with different cutout shapes of various sizes and their responses to hygrothermal environments under nonlinearly varying edge loads and is compared with the locally stiffened panels.Towards this,the modelling of the panel and stiffener is done by adopting nine-noded heterosis plate elements and three noded beam elements respectively.The stiffener formulation is suitably modified in order to take the torsional effect also into consideration along with the effect of shear deformation.Initially,the plate and the stiffener elements are treated separately,and then the displacement compatibility is maintained between them by using the transformation matrix.For a given loading and geometric discontinuity,the stress distribution within the perforated panel is highly non-uniform in nature and hence a dynamic approach has been used to calculate buckling loads by adopting two sets of boundary conditions,one set for pre-buckling stress analysis and the second set for buckling analysis.Four different quasi-isotropic stacking sequences are deliberated in this work by varying different ply-orientation in each scheme.The study also addresses the effect of various parameters such as nonlinear loads,hygro-thermal loads,cutout size and shapes,position of cutout,stiffener parameters,stacking sequences,thickness of plate and boundary conditions.

关 键 词：Locally stiffened panels Buckling VIBRATION Cutouts HETEROSIS Hygrothermal environment 

分 类 号：O344[理学—固体力学]