Analysis and Design Issues for Modern Aerospace Vehicles最新文献_第3页

Properties of Sandwich Structures With Reinforced Core 增强芯层夹层结构的性能研究

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0733

C. Sun, R. S. Hasebe, Y. Hua

引用次数: 0

Minimization of the Periodic Thermoelastic Deformation in Space Structures by Active Loads 主动载荷作用下空间结构周期性热弹性变形的最小化

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0719

O. Rand, D. Givoli

引用次数: 0

Minimum Deflection Design of Piezothermoelastic Laminated Composite Plates 压热弹性层合复合材料板的最小挠度设计

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0727

T. R. Tauchert, S. Adali, V. Verijenko, Alexa Richter

引用次数: 1

A Refined Theory for the Analysis of Sandwich Beams and its Application to Local and Global Stability Investigations 一种改进的夹层梁分析理论及其在局部和整体稳定性研究中的应用

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0737

H. Meyer-Piening

{"title":"A Refined Theory for the Analysis of Sandwich Beams and its Application to Local and Global Stability Investigations","authors":"H. Meyer-Piening","doi":"10.1115/imece1997-0737","DOIUrl":"https://doi.org/10.1115/imece1997-0737","url":null,"abstract":"\u0000 An analytical method is proposed to study the local and global instability of three-layered assymmetric sandwich beams with arbitrary relative face thicknesses ranging from very thin faces to a vanishing core height. The method accounts for extensional orthotropy, shear elasticity, Poisson’s ratio effects and lateral compressibility within each layer. As each layer is modelled in an identical manner and all stress and displacement related interface conditions are satisfied, there is no limitation with regard to geometry relations, except for numerical instabilities or convergence criteria. The displacement functions are represented by Fourier series which leads to a set of 12 linear equations for each value of the harmonic m The eigenfunction associated with the minimum load will then represent the (local or global) design buckling (or wrinkling) mode.\u0000 The results can be compared with buckling formulas like that proposed by Hoff [1] or the formula related to a beam on elastic foundation [2], as well as the approximation for Euler columns accounting for shear elasticity. It becomes evident that modifications to the aproximate methods may be suitable for some geometric relations and material properties.","PeriodicalId":403237,"journal":{"name":"Analysis and Design Issues for Modern Aerospace Vehicles","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124403574","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: 4

Thermomechanical Response of Laminated Flat Panels Featuring Interlaminar Bonding Imperfections 具有层间键合缺陷的层合平板的热力学响应

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0723

U. Icardi, M. Sciuva, L. Librescu

引用次数: 6

Comparison of Fretting Fatigue Crack Nucleation Experiments to Multiaxial Fatigue Theory Life Predictions 微动疲劳裂纹形核实验与多轴疲劳理论寿命预测的比较

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0745

T. Farris

{"title":"Comparison of Fretting Fatigue Crack Nucleation Experiments to Multiaxial Fatigue Theory Life Predictions","authors":"T. Farris","doi":"10.1115/imece1997-0745","DOIUrl":"https://doi.org/10.1115/imece1997-0745","url":null,"abstract":"\u0000 Fretting is associated with microslip at the interface of contacts experiencing oscillatory loads. One consequence of fretting is the formation and subsequent growth of cracks at the edge of contact, a phenomenon known as fretting fatigue. Fretting fatigue is an important high cycle fatigue failure mechanism in aircraft structural lap joints and turbine blade/disk contacts. A well-characterized, integrated fretting test system has been developed in which both normal and cyclic tangential fretting loads are applied and monitored in conjunction with a bulk load on the specimen. The experimental data includes histories of the three applied forces and a detailed record of the evolution of interfacial friction coefficient, as driven by the surface microslip. The experimental system has been exercised to observe fretting crack nucleation and growth under a wide range of loading conditions in the context of a statistically-designed test matrix. An extensive multiaxial fatigue analysis based on the stress-strain cycle experienced by each point of the bodies subjected to the fretting loads reveals that the critical location for crack formation is the trailing edge of contact, consistent with observations made in the laboratory. The resulting stress-strain cycles are coupled with strain-life theory and literature values of uniaxial fatigue constants to predict fretting fatigue crack nucleation. The data collected for 2024-T351 aluminum alloy correlates very well with this prediction.","PeriodicalId":403237,"journal":{"name":"Analysis and Design Issues for Modern Aerospace Vehicles","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124656790","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: 6

Vibration and Flutter Analysis of Stiffened Composite Plate Considering Thermal Effect 考虑热效应的加筋复合材料板振动与颤振分析

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0716

In Lee, I. Oh, Dong-Min Lee

{"title":"Vibration and Flutter Analysis of Stiffened Composite Plate Considering Thermal Effect","authors":"In Lee, I. Oh, Dong-Min Lee","doi":"10.1115/imece1997-0716","DOIUrl":"https://doi.org/10.1115/imece1997-0716","url":null,"abstract":"\u0000 Vibration and flutter analyses have been performed for stiffened composite laminated plates considering thermal effect. The FSDT (First order Shear Deformable plate Theory) and Timoshenko beam theory are used for the finite element modeling of a skin panel and stiffeners, respectively. The von Karman nonlinear strain-displacement relation is adopted to consider a large deflection due to the thermal buckling loads and severe aerodynamic loads. The first order piston theory is used for the modeling of aerodynamic loads. The temperature distribution is assumed to be constant over the surface and has a thermal gradient through the thickness of the plate. It is assumed that a degradation of the elastic properties of the constituent materials is a function of the temperature field itself. Guyan reduction method is employed to reduce the problem size and computational time. Newton-Rhapson iteration method is used to obtain the postbuckled deflection. Complex eigenvalue solver with LUM/NTF approximation method is used to obtain vibration and flutter characteristics. The effects of various parameters, such as ply orientation, temperature gradient, material property degradation and the stiffening scheme on flutter characteristics are investigated through some numerical examples. The degradation of material properties affects the aero-thermo-postbuckled deflection, vibration characteristics and flutter boundary. The selection of proper stiffening scheme results in great improvements of flutter characteristics of laminated panels without introducing considerable weight penalty.","PeriodicalId":403237,"journal":{"name":"Analysis and Design Issues for Modern Aerospace Vehicles","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127825865","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

Scaling Effects in Composite Laminates Under Tensile, Flexural, and Compressive Loading 复合材料层合板在拉伸、弯曲和压缩载荷下的结垢效应

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0709

D. P. Johnson, Joseph H. Felts, Michael T. Ho

引用次数: 0

Prediction of First Ply Failure in Scaled Cross-Ply Composite Laminates 尺度交叉铺层复合材料层合板首层破坏预测

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0705

K. Jackson

{"title":"Prediction of First Ply Failure in Scaled Cross-Ply Composite Laminates","authors":"K. Jackson","doi":"10.1115/imece1997-0705","DOIUrl":"https://doi.org/10.1115/imece1997-0705","url":null,"abstract":"\u0000 Previous research on scaling effects in composite materials has demonstrated that the stress levels at first ply failure and ultimate failure of composite laminates are dependent on the size of the laminate. In particular, the thickness dimension has been shown to be the most influential parameter in strength scaling of composite coupons loaded in tension. Geometrically and constitutively scaled laminates exhibit decreasing strength with increasing specimen size, and the magnitude of the strength-size effect is a function of both material properties and laminate stacking sequence. Some of the commonly used failure criteria for composite materials such as maximum stress, maximum strain, and tensor polynomial (e.g., Tsai-Wu) cannot account for the strength-size effect In this paper, three concepts are developed and evaluated for incorporating size dependency into failure criteria for composite materials. An experimental program of limited scope was performed to determine the first ply failure stress in scaled cross-ply laminates loaded in tension. Test specimens were fabricated from AS4/3502 graphite-epoxy composite material with laminate stacking sequences of [0°n/90°n/0°n]T where n = 1–6. Two experimental techniques were used to determine first ply failure, defined as a transverse matrix crack in the 90° ply: (1) step loading with dye penetrant x-ray of the specimen at each load interval, and (2) acoustic emission. The best correlation between first ply failure analysis and experimental data was obtained using a modified Weibull approach which incorporated the residual thermal stress and the outer ply constraint, as well as the ply thickness effect A second set of experiments was performed to determine the tensile response and ultimate failure of the scaled cross-ply laminates. The results of these experiments indicated no influence of specimen size on tensile response or ultimate strength.","PeriodicalId":403237,"journal":{"name":"Analysis and Design Issues for Modern Aerospace Vehicles","volume":"450 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114151492","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

Nonlinear Analysis of Curved Composite Panels Subjected to Combined Temperature Gradient and Mechanical Loads 复合材料弯曲板在温度梯度和机械载荷作用下的非线性分析

Analysis and Design Issues for Modern Aerospace Vehicles Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0717

A. Noor, J. Peters

{"title":"Nonlinear Analysis of Curved Composite Panels Subjected to Combined Temperature Gradient and Mechanical Loads","authors":"A. Noor, J. Peters","doi":"10.1115/imece1997-0717","DOIUrl":"https://doi.org/10.1115/imece1997-0717","url":null,"abstract":"\u0000 The results of a detailed study of the effect of cutout on the nonlinear response of curved unstiffened panels are presented. The panels are subjected to combined temperature gradient through-the-thickness combined with pressure loading and edge shortening or edge shear. The analysis is based on a first-order shear-deformation Sanders-Budiansky type shell theory with the effects of large displacements, moderate rotations, transverse shear deformation and laminated anisotropic material behavior included. A mixed formulation is used with the fundamental unknowns consisting of the generalized displacements and the stress resultants of the panel. The nonlinear displacements, strain energy, principal strains, transverse shear stresses, transverse shear strain energy density, and their hierarchical sensitivity coefficients are evaluated. The hierarchical sensitivity coefficients measure the sensitivity of the nonlinear response to variations in the panel parameters, as well as in the material properties of the individual layers. Numerical results are presented for cylindrical panels and show the effects of variations in the loading and the size of the cutout on the global and local response quantities and their sensitivity to changes in the various panel, layer and micromechanical parameters.","PeriodicalId":403237,"journal":{"name":"Analysis and Design Issues for Modern Aerospace Vehicles","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121751876","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