Influence of Delamination on Strength of Externally Pressurized Glass/Epoxy Cylinders

1999 ◽  
Author(s):  
Peter Davies ◽  
Leif A. Carlsson
Keyword(s):  
Impact Damage ◽  
Compressive Load ◽  
External Pressure ◽  
Cylinder Wall ◽  
Failure Pressure ◽  
Filament Wound ◽  
Local Reduction ◽  
Delamination Resistance ◽  
Cylinder Strength ◽  
Winding Angle

Abstract The delamination resistance of filament wound glass/epoxy cylinders has been characterized for a range of winding angles and fracture mode ratios using beam fracture specimens. The results reveal that the fracture resistance increases with increasing winding angle and mode II (shear) fraction (GII/G). It was also found that interlaced fiber bundles in the filament wound cylinder wall acted as effective crack arresters in mode I loading. To examine the sensitivity of delamination damage on the implosion behavior of cylinders, external pressure tests were performed on filament-wound glass/epoxy composite cylinders with artificial defects and impact damage. The results revealed that the cylinder strength was insensitive to the presence of single delaminations but impact damage caused reductions in failure pressure. The insensitivity of the failure pressure to a single delamination is attributed to the absence of buckling of the delaminated sublaminates before the cylinder wall collapsed. The impacted cylinders contained multiple delaminations, which caused local reduction in the compressive load capability and reduction in failure pressure.

Experimental Analysis of Kenaf Filament Wound Tubes under Axial Compression Load

2014 ◽  
Vol 660 ◽  
pp. 778-782
Author(s):  
Iqbal Mokhtar ◽  
Mohd Yazid Yahya ◽  
Ab Saman Abd Kader ◽  
Shukur Abu Hassan
Keyword(s):  
Compressive Strength ◽  
Axial Compression ◽  
Compression Test ◽  
Compressive Load ◽  
Compression Load ◽  
Filament Wound ◽  
Filament Wound Composite ◽  
Glass Tubes ◽  
Winding Angle ◽  
Early Indication

The objective of this study was to determine the strength of kenaf filament wound tubes under axial compression load. Kenaf is natural reinforcement fibre in which need to explore its capability to replace and compare with other common commercial reinforcement materials. Axial compression test was performed as early indication to identify the performance of kenaf filament wound composite tubes. Comparisons have been done towards basalt, e-glass and carbon tubes using polyester as a resin. Axial compression test of kenaf/polyester and kenaf/epoxy tubes were conducted with different winding angles involved which are 450, 550, 650 and 750. The result shows the 450 kenaf/epoxy tubes generated the higher compressive strength followed by other winding angle in the ascending order. The layer strength identification have been conducted in 550 winding angle sample in which indicate the increment layer of winding is uniform between one, two and three layers in ascending orders. Comparison between the different reinforcement materials show carbon tubes produced the higher compressive strength followed by e-glass, basalt and kenaf. Kenaf/epoxy recorded 38.7% lower the e-glass tubes. Kenaf/epoxy tubes were observed to identify the improvement from kenaf/polyester tubes and results shows at least 22% increment have been generated. It can be concluded that kenaf presence as a reinforcement material was successfully combine as composite system under axial compressive load as well as lead to the promising indication to be introduced in low load bearing application.

scholarly journals Cylinders with a steel-concrete-steel wall to resist external pressure

2018 ◽  
Author(s):  
Charles Douglas Goode ◽  
Tom Nash
Keyword(s):  
Failure Load ◽  
External Pressure ◽  
Cylinder Wall ◽  
Failure Pressure ◽  
Different Depths ◽  
Composite Wall

In the 1980’s Manchester University carried out over 110 tests on cylinders with a composite wall (steel-concrete-steel) subjected to external pressure as already reported in the literature.  This paper describes further tests on 9 cylinders with a composite wall and a dome end subjected to external pressure and reports the results and compares them with theory.  The cylinders were 500 mm diameter and 1250 mm long and four of them had penetrations through the cylinder wall.  These tests were carried out under contract for Tecnomare SpA of Italy and have not been previously reported because of confidentiality reasons.  The agreement between test behaviour, failure load and the theory developed at Manchester University is good. The philosophy for the design of such vessels for seabed structures is discussed and a ‘depth margin’ method proposed as it is a more realistic way of applying safety.  Examples of designs for different depths are given and compared with the predicted failure pressure. 

Investigation of the mechanical and forming behaviour of 3D warp interlock carbon woven fabrics for complex shape of composite material

2021 ◽  
pp. 152808372098410
Author(s):  
Mehmet Korkmaz ◽  
Ayşe Okur ◽  
Ahmad Rashed Labanieh ◽  
François Boussu
Keyword(s):  
Composite Materials ◽  
Complex Shape ◽  
Impact Damage ◽  
Woven Fabrics ◽  
Forming Process ◽  
Warp Yarn ◽  
Delamination Resistance ◽  
Fabric Architecture ◽  
Weave Pattern ◽  
Carbon Fabrics

Composite materials which are reinforced with 3D warp interlock fabrics have outstanding mechanical properties such as higher delamination resistance, ballistic damage resistance and impact damage tolerance by means of their improved structural properties. Textile reinforcements are exposed to large deformations in the production stage of composite materials which have complex shape. Although good formability properties of 3D warp interlock fabrics in forming process were already proven by recent studies, further information is needed to elucidate forming behaviours of multi-layer fabrics which is produced with high stiffness yarns like carbon. In this study, 3D warp interlock carbon fabrics were produced on a prototype weaving loom and the same carbon yarn was used in two fabric directions with equal number of yarn densities. Fabrics were differentiated with regard to the presence of stuffer warp yarn, weave pattern and parameters of binding warp yarn which are angle and depth. Therefore, the effect of fabric architecture on the mechanical and formability properties of 3D warp interlock carbon fabrics could be clarified. Three different breaking behaviours of fabrics were detected and they were correlated with crimp percentages of yarn groups. In addition, the bending and shear deformations were analysed in view of parameters of fabric architectures. Two distinct forming behaviours of fabrics were determined according to the distribution of deformation areas on fabrics. Moreover, the optimal structure was identified for forming process considering the fabric architecture.

Tolerance of Composite Pipes to Local Impact Damage

1996 ◽  
Vol 210 (3) ◽  
pp. 181-192 ◽  
Author(s):  
S R Reid ◽  
C Peng ◽  
J N Ashton
Keyword(s):  
Damage Tolerance ◽  
Impact Damage ◽  
Local Loading ◽  
Experimental Programme ◽  
Filament Wound ◽  
Nose Shape ◽  
Local Impact ◽  
Chopped Strand Mat ◽  
Composite Pipes

The results of an extensive experimental programme on local loading of composite pipes are presented. Particular attention is directed to the influence of projectile nose shape on the damage tolerance of the pipes. Both filament wound pipes and lined chopped-strand mat pipes are considered.

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