A Study of Jones’ Equation for Buckling of Laminated Composite Cylinders Under External Hydrostatic Pressure

1993 ◽  
Vol 37 (03) ◽  
pp. 239-252
Author(s):  
Thomas Perry ◽  
Zan Miller

A classical solution derived by Jones (1968) is used to evaluate the buckling performance of unstiffened generally orthotropic and quasi-isotropic laminated Graphite/Epoxy (GREP) composite cylinders subjected to external hydrostatic pressure. The results of the analysis are compared to finite-element analysis results. Hydrostatic testing to failure of several 12-ply T300/5208 GREP cylinders demonstrated that the classical buckling solution is quite accurate. The finite-element results showed good agreement with both Jones' solution and test data, with several notable exceptions. Evaluation of strain gage data via Southwell's (1932) method indicates that the test cylinders were fabricated very nearly true. A postiori buckling predictions using Southwell plots all compared quite favorably with the Jones' equation predictions. This work demonstrates that a relatively simple analytical solution can reliably evaluate the performance of composite materials in pressure hull applications.

Author(s):  
Yeqing Wang ◽  
Olesya I. Zhupanska ◽  
Crystal L. Pasiliao

One of the prevalent approaches to model ablation problems is to use the UMESHMOTION subroutine and the Arbitrary Lagrangian-Eulerian (ALE) adaptive remesh algorithm in ABAQUS (i.e., a commercial, general purpose Finite Element Analysis (FEA) software). However, the approach is not applicable for ablation problems when the material removal proceeds from one material domain to another, such as for ablations of laminated composite materials when the surface recedes from one laminate layer to another layer with different material orientations. In this paper, a novel procedure, based on manual mesh moving FEA with ABAQUS, is proposed to solve the ablation problems for laminated composite materials. The proposed procedure is verified by comparing the predictions of temperature and ablation histories of a two-dimensional isotropic panel (i.e., with single material domain) with those obtained using the traditional UMESHMOTION+ALE method. In addition, a case study is presented to demonstrate the successful application of the proposed procedure for the prediction of the thermal and ablation response of a laminated carbon fiber reinforced epoxy matrix (CFRP) composite panel subjected to a high-intensity and short-duration radiative heat flux.


2009 ◽  
Vol 131 (4) ◽  
Author(s):  
H. F. Wang ◽  
Z. F. Sang ◽  
L. P. Xue ◽  
G. E. O. Widera

The burst pressure of cylinders with hillside nozzle is determined using both experimental and finite element analysis (FEA) approaches. Three full-scale test models with different angles of the hillside nozzle were designed and fabricated specifically for a hydrostatic test in which the cylinders were pressurized with water. 3D static nonlinear finite element simulations of the experimental models were performed to obtain the burst pressures. The burst pressure is defined as the internal pressure for which the structure approaches dimensional instability, i.e., unbounded strain for a small increment in pressure. Good agreement between the predicted and measured burst pressures shows that elastic-plastic finite element analysis is a viable option to estimate the burst pressure of the cylinders with hillside nozzles. The preliminary results also suggest that the failure location is near the longitudinal plane of the cylinder-nozzle intersection and that the burst pressure increases slightly with an increment in the angle of the hillside nozzle.


1991 ◽  
Vol 58 (3) ◽  
pp. 820-824 ◽  
Author(s):  
A. Bogobowicz ◽  
L. Rothenburg ◽  
M. B. Dusseault

A semi-analytical solution for plane velocity fields describing steady-state incompressible flow of nonlinearly viscous fluid into an elliptical opening is presented. The flow is driven by hydrostatic pressure applied at infinity. The solution is obtained by minimizing the rate of energy dissipation on a sufficiently flexible incompressible velocity field in elliptical coordinates. The medium is described by a power creep law and solutions are obtained for a range of exponents and ellipse eccentricites. The obtained solutions compare favorably with results of finite element analysis.


Author(s):  
Shivdayal Patel ◽  
Suhail Ahmad ◽  
Puneet Mahajan

The safety predictions of composite armors require a probabilistic analysis to take into consideration scatters in the material properties and initial velocity. Damage initiation laws are used to account for matrix and fiber failure during high-velocity impact. A three-dimensional (3D) stochastic finite-element analysis of laminated composite plates under impact is performed to determine the probability of failure (Pf). The objective is to achieve the safest design of lightweight composite through the most efficient ply arrangement of S2 glass epoxy. Realistic damage initiation models are implemented. The Pf is obtained through the Gaussian process response surface method (GPRSM). The antisymmetric cross-ply arrangement is found to be the safest based on maximum stress and Yen and Hashin criteria simultaneously. Sensitivity analysis is performed to achieve the target reliability.


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