Optimization of a composite cylinder under bending by tailoring stiffness properties in circumferential direction

Blom, Adriana W.; Stickler, Patrick B.; Gürdal, Zafer

doi:10.1016/j.compositesb.2009.10.004

Cited by 141 publications

(67 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is referred to as the variable-stiffness cylinder. The layup of both shells resulted from an optimization for maximum bending load subjected to stiffness, strength and manufacturing constraints, as described by Blom et al 1 The material used for manufacturing was slightly different from that used in the optimization described by Blom 1 and therefore the actual numbers of the optimal layups and buckling loads were also slightly different.…”

Section: Cylinder With Stiffness Variation In the Circumferentialmentioning

confidence: 99%

Bending Test of a Variable-Stiffness Fiber Reinforced Composite Cylinder

Blom¹,

Rassaian²,

Stickler³

et al. 2010

51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials ConferenceSelf Cite

7
0
2
0

View full text Add to dashboard Cite

Two carbon-fiber-reinforced composite cylinders were tested in bending. One cylinder, the baseline cylinder, consisted of 0• , 90• and ±45• plies, whereas the other cylinder, called the variable-stiffness cylinder, contained plies with fiber orientations that varied in the circumferential direction, which caused a variation in laminate stiffness. The cylinders were optimized for maximum buckling load carrying capability under bending. 1Simulations showed that the variable-stiffness cylinder was able to redistribute the applied loads around the circumference, resulting in lower strain values at both the tension and the compression side of the cylinder and an improvement of the buckling load by 18 percent compared to the baseline cylinder. The purpose of the bending test was to show that the improvements obtained in the analytical results could also be achieved experimentally. The baseline cylinder was tested first to serve as a benchmark for the variable-stiffness cylinder. The finite element model was adjusted based on the baseline cylinder tests to represent the experimental conditions correctly. The model took into account the flexible connection between the cylinder and the test fixture, the test mechanism and geometric imperfections present in the cylinder and showed good agreement with the experimental results. The variable-stiffness cylinder was tested twice: first oriented in the direction it was designed for and later rotated 180 degrees about the cylinder axis, such that the loading direction on the cylinder was reversed. The predicted global response and strain distributions for both configurations corresponded well with the experimental data. The flexible boundary conditions and the geometric imperfections affected the load and strain distributions of the baseline and the variable-stiffness cylinders, but the relative improvements of the variablestiffness cylinder in the preferred orientation with respect to the baseline cylinder were not affected. Follow-up tests of the cylinders including cutouts or induced damage are planned in the future.

show abstract

Section: Cylinder With Stiffness Variation In the Circumferentialmentioning
confidence: 99%

Bending Test of a Variable-Stiffness Fiber Reinforced Composite Cylinder
Blom¹,
Rassaian²,
Stickler³
et al. 2010
51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials ConferenceSelf Cite
7
0
2
0
View full text Add to dashboard Cite

show abstract

“…Circumferential tailoring of circular cylinder has been previously studied by Blom et al 1 have optimised a circular cylinder to carry maximum buckling load under bending by using constant curvature fiber paths while applying a strength constraint. Analysis and optimisation of the buckling load of elliptical cross-section cylinders under axial compression and torsion has been studied by some researchers 2 -4 using fibre angles and laminate thickness as design variables.…”

Section: Introductionmentioning
confidence: 99%

Maximum Buckling Load Design of General Cross-section Cylinders Using Lamination Parameters
Ali
¹
,
Abdalla
²
,
Gürdal
³

2010
13th AIAA/ISSMO Multidisciplinary Analysis Optimization Conference
Self Cite
4
0
1
0
View full text Add to dashboard Cite

For a non-circular cylinder the radius of curvature changes around the circumference. Therefore for constant stiffness non-circular cylinders, some specific locations in the circumference are more prone to buckle. The same problem exists for circular cylinders with non-uniform loading in the cross-section like a cylinder under bending. This explanation brings to the mind the idea of tailoring the material such that the material potential is used more efficiently and if possible all parts of the cylinder contribute in the buckling phenomenon. Since the changes in the radius of curvature and/or loading happens in the circumferential direction, tailoring the material properties in the circumferential direction is a logical pattern. By assigning a certain number of half-waves in the longitudinal direction, the buckling eigen-value problem is solved to find the buckling load and circumferential mode shapes. The inverse of buckling load is approximated using a homogeneous, conservative formulation to increase the computational efficiency during optimisation. This is a hybrid approximation expanded in terms of stiffness linearly and reciprocally. Multimodal optimisation problem is formulated to minimise inverse of critical buckling factor. Variable stiffness design is compared with the quasi-isotropic design.

show abstract

“…in bending. Therefore, extensive research works have been performed subsequently to improve the bending-induced buckling capacity of circular VS composite cylinders [5,7,8,9]. The inhomogeneity of the section load in the skin arising from overall bending gives designers suitable scope to vary the orientation angle of fibers from the compressive side to the tension side so that the section loads are redistributed more efficiently.…”

Section: Introductionmentioning
confidence: 99%

“…The resulting so-called variable stiffness (VS) composite laminate offers the designers more scope to use the directional properties of the material more efficiently to produce VS composite cylinders [5,6,7,8,9] with better structural performance compared with their traditional Constant Stiffness (CS) counterparts. However, this improvement is at the expense of adding more complexity to the design optimization process because of the increased number of design variables.…”

Section: Introductionmentioning
confidence: 99%

Stiffness tailoring of elliptical composite cylinders for axial buckling performance
Rouhi
¹
,
Ghayoor
²
,
Hoa
³

et al. 2016
Composite Structures
45
0
14
0
View full text Add to dashboard Cite

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. AbstractAutomated fiber placement (AFP) machines have made it possible to tailor the material stiffness properties in a laminated composite structure by fiber steering. The so-called variable stiffness (VS) laminate can be designed to improve the structural performance of a composite component. Herein, using a metamodeling based design optimization (MBDO) method, elliptical composite cylinders with VS laminate are designed and optimized for maximum axial buckling capacity. The effect of cross-sectional aspect ratio of the elliptical cylinders on the potential improvement of the buckling capacity is also investigated. As the baseline for comparison, for each cross-sectional aspect ratio, the buckling capacity of elliptical cylinders with quasi-isotropic (QI) and optimum constant stiffness (CS) laminates are also calculated. It is found that the buckling capacity of an elliptical composite cylinder can be improved by fiber steering up to 118% compared with its best CS counterpart.

show abstract

Optimization of a composite cylinder under bending by tailoring stiffness properties in circumferential direction

Cited by 141 publications

References 11 publications

Bending Test of a Variable-Stiffness Fiber Reinforced Composite Cylinder

Bending Test of a Variable-Stiffness Fiber Reinforced Composite Cylinder

Maximum Buckling Load Design of General Cross-section Cylinders Using Lamination Parameters

Stiffness tailoring of elliptical composite cylinders for axial buckling performance

Contact Info

Product

Resources

About