Buckling Analysis of Nonlocal Anisotropic Thin-Walled Cylindrical Shells Subject to Combined Loading

2016 ◽  
Vol 142 (12) ◽  
pp. 06016009 ◽  
Author(s):  
Esmaeal Ghavanloo ◽  
S. Ahmad Fazelzadeh ◽  
Saeed Sohrabpour
2018 ◽  
Vol 877 ◽  
pp. 453-459
Author(s):  
B. Angelina Catherine ◽  
R.S. Priyadarsini

Buckling is a prominent condition of instability caused to a shell structure as a result of axial loadings. The process of buckling becomes more complex while analyzing thin walled structures like shells. Today such thin walled laminated composite shells are gaining more importance in many defense and industrial applications since they have greater structural efficiency and performance in relation to isotropic structures. Comprehensive understanding of the buckling response of shell structures is necessary to assure the integrity of these shells during their service life. The presence of defects, such as cracks, may severely compromise their buckling behavior and jeopardize the structural integrity. This work aims in conducting numerical analysis of cracked GFRP (Glass fibre-reinforced polymer) composite cylindrical shells under combined loading to study the effect of crack size on the buckling behavior of laminated composite cylindrical shells with different lay-up sequences. The numerical analyses were carried out using the finite element software, ABAQUS in order to predict the buckling behaviour of cracked laminated composite cylinders subject to different combinations of axial compression, torsion, internal pressure and external pressure from the interaction buckling curves.


Vestnik MGSU ◽  
2021 ◽  
pp. 577-586
Author(s):  
Stepan V. Cheremnykh ◽  
Sergei A. Sokolov

Introduction. It is necessary to improve methods of analysis of the limit states, occurring when a thin-walled shell is in the elastoplastic domain, to use these cylindrical shells as elements of heavily loaded products of construction and machine building industries. Materials and methods. The problem of stability of a circular thin-walled cylindrical shell, made of steel 45 GOST 1050-2013, that takes the load induced by pure compression and axial torsion, has been studied. Besides, experimental and theoretical components of the problem have been analyzed. Experimental facility SN-EVM was applied to perform an experiment test and analyze its findings in terms of different versions of the theory of plasticity used to solve shell stability problems beyond the elastic limit. The co-authors emphasize the unavailability of any definition of the criterion of stability loss under combined loading based on experimental dependences that were identified earlier. The results of the experiment were compared with the results of the theoretical study. The analysis of the shell stability in the case of complex subcritical loading are based on the A.A. Ilyushin theory of stability, in which plasticity functions are taken according to V.G. Zubchaninov’s approximations. Results. The problem was solved using the software programme, developed by the co-authors. The software solves the bifurcation problem of a cylindrical shell with regard for the complex nature of deformations at the moment of stability loss in the case of exposure to complex subcritical loading, commensurable processes and the trajectory that has the form of circular arcs. It has been shown that the proposed method of analysis and approximations describe the real stress-strain state of shells that feature low flexibility in respect of a complex pattern of deformation and characterize a stable state of the material beyond the elastic limit. Conclusions. The theoretical strength and deformability analysis of a cylindrical shell and its experimental studies demonstrate sufficient convergence which proves their reliability. This conclusion will allow to improve the process of design of structural elements made of materials that have complex mechanical properties.


1974 ◽  
Vol 96 (4) ◽  
pp. 1322-1327
Author(s):  
Shun Cheng ◽  
C. K. Chang

The buckling problem of circular cylindrical shells under axial compression, external pressure, and torsion is investigated using a displacement function φ. A governing differential equation for the stability of thin cylindrical shells under combined loading of axial compression, external pressure, and torsion is derived. A method for the solutions of this equation is also presented. The advantage in using the present equation over the customary three differential equations for displacements is that only one trial solution is needed in solving the buckling problems as shown in the paper. Four possible combinations of boundary conditions for a simply supported edge are treated. The case of a cylinder under axial compression is carried out in detail. For two types of simple supported boundary conditions, SS1 and SS2, the minimum critical axial buckling stress is found to be 43.5 percent of the well-known classical value Eh/R3(1−ν2) against the 50 percent of the classical value presently known.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 592
Author(s):  
Feng Yue ◽  
Ziyan Wu

The fracture mechanical behaviour of thin-walled structures with cracks is highly significant for structural strength design, safety and reliability analysis, and defect evaluation. In this study, the effects of various factors on the fracture parameters, crack initiation angles and plastic zones of thin-walled cylindrical shells with cracks are investigated. First, based on the J-integral and displacement extrapolation methods, the stress intensity factors of thin-walled cylindrical shells with circumferential cracks and compound cracks are studied using linear elastic fracture mechanics, respectively. Second, based on the theory of maximum circumferential tensile stress of compound cracks, the number of singular elements at a crack tip is varied to determine the node of the element corresponding to the maximum circumferential tensile stress, and the initiation angle for a compound crack is predicted. Third, based on the J-integral theory, the size of the plastic zone and J-integral of a thin-walled cylindrical shell with a circumferential crack are analysed, using elastic-plastic fracture mechanics. The results show that the stress in front of a crack tip does not increase after reaching the yield strength and enters the stage of plastic development, and the predicted initiation angle of an oblique crack mainly depends on its original inclination angle. The conclusions have theoretical and engineering significance for the selection of the fracture criteria and determination of the failure modes of thin-walled structures with cracks.


Sign in / Sign up

Export Citation Format

Share Document