Thick Composites for Load Bearing Structures最新文献

Subsonic and Intersonic Dynamic Crack Growth in Unidirectional Composites 单向复合材料的亚音速和跨音速动态裂纹扩展

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0906

D. Coker, A. Rosakis, Yonggang Huang

引用次数: 2

Equivalent Composite Laminated Beams With Various Elastic Constitutive Models 具有不同弹性本构模型的等效复合层合梁

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0905

I. Sheinman, Y. Frostig

引用次数: 0

Postbuckling and Growth Behavior of Face-Sheet Delaminations in Sandwich Composites 夹层复合材料表面层脱层的后屈曲和生长行为

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0903

George A. Kadomateas

{"title":"Postbuckling and Growth Behavior of Face-Sheet Delaminations in Sandwich Composites","authors":"George A. Kadomateas","doi":"10.1115/imece1999-0903","DOIUrl":"https://doi.org/10.1115/imece1999-0903","url":null,"abstract":"\u0000 A bending load on a sandwich beam consisting of two fiber-reinforced sheets (skins) separated by a low stiffness core is equivalent to a compressive force on one face and a tensile force on the other. Should an interface crack between the layers of the composite face-sheet or between the core and the composite face-sheet exists on the compressively loaded face, local buckling and subsequently growth of this interface crack (delamination) may occur. This may also naturally occur under pure compression. In this study, the buckling, postbuckling and delamination growth behavior is studied through a procedure that is based on the large deflections of the delaminated layer. First, the solution is derived for the postbuckled states by using the elastica theory to model the large deflections of the thin delaminated layer and the sandwich beam theory (for unsymmetric sections) that includes transverse shear, to model the (relatively modest) deflections of the rest of the structure. This postbuckling solution is subsequently used to study the growth of the mixed mode interface crack through an energy release rate approach. The consequences of the elastic mismatch between core and face sheet are discussed and illustrative results are presented for several sandwich construction configurations.","PeriodicalId":136673,"journal":{"name":"Thick Composites for Load Bearing Structures","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133104794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Influence of Delamination on Strength of Externally Pressurized Glass/Epoxy Cylinders 分层对外压玻璃/环氧钢瓶强度的影响

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0908

P. Davies, L. Carlsson

{"title":"Influence of Delamination on Strength of Externally Pressurized Glass/Epoxy Cylinders","authors":"P. Davies, L. Carlsson","doi":"10.1115/imece1999-0908","DOIUrl":"https://doi.org/10.1115/imece1999-0908","url":null,"abstract":"\u0000 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.","PeriodicalId":136673,"journal":{"name":"Thick Composites for Load Bearing Structures","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124379878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Mixed Mode Stress Singularities in Anisotropic Composites 各向异性复合材料的混合模应力奇异性

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0901

W. Yin

{"title":"Mixed Mode Stress Singularities in Anisotropic Composites","authors":"W. Yin","doi":"10.1115/imece1999-0901","DOIUrl":"https://doi.org/10.1115/imece1999-0901","url":null,"abstract":"\u0000 Multi-material wedges composed of fully anisotropic elastic sectors generally show intrinsic coupling of the anti-plane and in-plane modes of deformation. Each anisotropic sector has three complex conjugate pairs of material eigensolutions whose form of expression depends on five distinct types of anisotropic materials. Continuity of the displacements and the tractions across the sector interfaces and the traction-free conditions on two exterior boundary edges determine an infinite sequence of eigenvalues and eigensolutions of the multi-material wedge. These eigensolutions are linearly combined to match the traction-boundary data (generated by global finite element analysis of the structure) on a circular path encircling the singularity. The analysis method is applied to a bimaterial wedge near the free edge of a four-layer angle-ply laminate, and to a trimaterial wedge surrounding the tip of an embedded oblique crack in a three-layer composite. Under a uniform temperature load, the elasticity solution based on the eigenseries yields interfacial stresses that are significantly different from the asymptotic solution (given by the first term of the eigenseries), even as the distance from the singularity decreases to subatomic scales. Similar observations have been found previously for isotropic and orthotropic multi-material wedges. This raises serious questions with regard to characterizing the criticality of stress singularity exclusively in terms of the asymptotic solution and the associated stress intensity factors or generalized stress intensity factors.","PeriodicalId":136673,"journal":{"name":"Thick Composites for Load Bearing Structures","volume":"419 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123145587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Analysis of Nonlinear Flexural Behavior of Thick Composites With Fiber Waviness 含纤维波纹的厚复合材料非线性弯曲性能分析

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0899

H. Chun, S. Lee, I. Daniel

引用次数: 0

Mixed Mode Interface Cracks in a Bi-Material Half Plane and a Bi-Material Strip 双材料半平面和双材料带状混合模式界面裂纹

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0900

Haiying Huang, George A. Kadomateas, V. L. Saponara

引用次数: 0

Three Dimensional Effects in Composite Plates 复合板的三维效应

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0904

S. Prabhu, J. Lambros

{"title":"Three Dimensional Effects in Composite Plates","authors":"S. Prabhu, J. Lambros","doi":"10.1115/imece1999-0904","DOIUrl":"https://doi.org/10.1115/imece1999-0904","url":null,"abstract":"\u0000 In this study, a finite element investigation of the three dimensional nature of stress fields in the near tip region of a cracked orthotropic plate was conducted. Two and three dimensional finite element analyses were used to investigate the relative extent of regions of three dimensional to two dimensional (plane stress or plane strain) deformation in the cracked plate. The material properties used in the simulations corresponded to those of a graphite/epoxy composite. A three point bend loading geometry, with the fiber directions either parallel or perpendicular to the crack, was simulated. In analogy to isotropic materials, it was observed that a plane stress K-dominant region does not arise arbitrarily close to the crack tip because of the existence of a three dimensional zone. However, it was seen that the shape and the size of this three dimensional zone in the cracked composite plate is substantially different from that of an isotropic plate, and depends intimately on material properties. For a crack parallel to the fiber direction the three dimensional zone extends to 0.46h (h = specimen thickness) ahead of the crack tip but only to 0.27h at 30°. Fibers perpendicular to the crack produce a highly elongated three dimensional zone in the direction of the fibers (up to 0.78h). The zone is also sensitive to the variations in the Poisson’s ratio’s of the orthotropic solid.","PeriodicalId":136673,"journal":{"name":"Thick Composites for Load Bearing Structures","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134106084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High Strain Rate Response of Resin Infusion Molded Sandwich Composites 树脂注射成型夹层复合材料的高应变速率响应

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0909

H. Mahfuz, W. Al Mamun, H. Mohamed, U. Vaidya, A. Haque, S. Jeelani

{"title":"High Strain Rate Response of Resin Infusion Molded Sandwich Composites","authors":"H. Mahfuz, W. Al Mamun, H. Mohamed, U. Vaidya, A. Haque, S. Jeelani","doi":"10.1115/imece1999-0909","DOIUrl":"https://doi.org/10.1115/imece1999-0909","url":null,"abstract":"\u0000 Foam core sandwich composites have been tested under high strain rate (HSR) loading in the thickness direction. The regular Split Hopkinson Pressure Bar (SHPB) has been modified by replacing the steel transmitter bar by a polycarbonate bar. This modification resulted in stronger signals from the transmitter bar, which would otherwise be very feeble especially when testing soft materials. New sets of mathematical formulations have been derived to account for the impedance mismatch between the incidence and transmitter bars. The modified equations are first verified with a known material and then used for sandwich composites. Three types of core with various densities have been tested under compression at strain rates ranging from quasi-static to 1000 S−1. The compressive failure stress has been observed to be directly proportional to the core density, as well as to the strain rate. The strain rate sensitivity was moderate, and the sandwich composites mostly failed by the collapse of the foam-cell. Delamination did not play a major role in the failure process. Details of the mathematical derivations and the analysis of the HSR behavior are presented in this paper.","PeriodicalId":136673,"journal":{"name":"Thick Composites for Load Bearing Structures","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115989583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Dynamic Behavior of Fiber Reinforced Composites Under Multiaxial Compression 纤维增强复合材料在多轴压缩下的动力特性

Thick Composites for Load Bearing Structures Pub Date : 1999-11-14 DOI: 10.1115/imece1999-0907

K. Oguni, G. Ravichandran

引用次数: 5