Aerospace and Materials最新文献_第3页

Micromechanical Study of Particulate Reinforced Composites 颗粒增强复合材料的微观力学研究

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0466

D. Choi, S. Nomura

引用次数: 0

Modeling of Porosity Effects in Gas-Filled Composites Using Biot’s Parameter 利用Biot参数模拟充气复合材料孔隙率效应

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0467

N. Salamon, R. Ganesan

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Effects of Defects in a New Form of Affordable Composite Materials-Rod Reinforcement 一种新型廉价复合材料——棒材增强材料中缺陷的影响

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0489

W. Chan, J. S. Wang

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Fatigue Damage Evolution in a Short Fiber Reinforced Metal Matrix Composite 短纤维增强金属基复合材料疲劳损伤演化研究

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0498

S. Canumalla, Robert N. Pangborn

{"title":"Fatigue Damage Evolution in a Short Fiber Reinforced Metal Matrix Composite","authors":"S. Canumalla, Robert N. Pangborn","doi":"10.1115/imece1996-0498","DOIUrl":"https://doi.org/10.1115/imece1996-0498","url":null,"abstract":"\u0000 The micromechanisms of fatigue failure of a short, alumina-silicate fiber reinforced cast aluminum alloy (A356) are investigated in this study. The nature of damage evolution is studied by three complementary perspectives — i) monitoring of the mechanical response, ii) microscopy on the gage length and fracture surface, and iii) probing of the microstructural changes in the bulk nondestructively using acoustic emission. The damage evolution in the composite is driven by strain or fatigue cycles imposed on the specimen and is manifested as three distinct mechanisms: a) cracking at hollow shot particles early in the life, b) microcracking in the form of fracture of fibers oriented in the direction of the loading and splitting or decohesion at fiber/matrix interface of transversely oriented fibers, and c) void formation at fiber ends and other stress concentrations. The interaction among the different modes, which defines the evolution of microstructural damage, is described. A flow chart for the progression of damage is presented and the most important steps in the damage evolution are identified. Suggestions are made for improving fatigue performance by tailoring the microstructure of the composite.","PeriodicalId":326220,"journal":{"name":"Aerospace and Materials","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114385535","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

Deformation and Fracture Response of Steel at High Temperature 钢在高温下的变形和断裂响应

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0465

F. Brust, Jinmiao Zhang

引用次数: 0

Thermal Softening of Glassy Particle Modified Tungsten 玻璃微粒改性钨的热软化

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0500

P. Leduc, G. Bao

引用次数: 0

The Influence of Fiber Distribution and Voids on the Tensile Strength of Polymer Composite Materials 纤维分布和空隙对高分子复合材料抗拉强度的影响

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0501

G. Generalis, M. Sundaresan

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Edge Stresses in a Laminated Composite Strip Subjected to Axial Temperature Gradients 受轴向温度梯度影响的层压复合材料带材的边缘应力

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0477

D. Swett, G. Shiflett

{"title":"Edge Stresses in a Laminated Composite Strip Subjected to Axial Temperature Gradients","authors":"D. Swett, G. Shiflett","doi":"10.1115/imece1996-0477","DOIUrl":"https://doi.org/10.1115/imece1996-0477","url":null,"abstract":"\u0000 One of the most severe problems associated with the use of laminated composite structures in thermal environments is the susceptibility to delamination due to the edge effect stresses arising from the thermal expansion mismatch between the constituent laminae. In addition, the problem may be compounded by the introduction of extreme thermal gradient effects as well. Trade studies to develop a satisfactory design for these types of thermal environments have heretofore been rather limited due to the lack of accurate analytical assessments for the edge effects that arise from these thermal loads. The predominant amount of investigation for these types of thermal gradient problems has been restricted to detailed numerical finite element analyses that do not lend to rapid concurrent engineering design processes. No analytical solution has been available to address the thermoelastic edge effects in composite laminates resulting from thermal gradients.\u0000 In this paper, a combination of Airy stress functions and direct displacement functions is utilized to obtain the plane elasticity solution for the stresses and displacements in a multilayer laminated anisotropic strip subjected to a temperature gradient that is arbitrarily symmetric in the longitudinal direction. The solution cannot be guaranteed to satisfy the free edge normal traction requirement since only resultant force is enforced to zero; however, convergence for enforced zero transverse slope at the strip ends can be established, as the eigenfunctions are orthogonal. Thus the solution is exact for these edge conditions. Numerical results are presented for several examples and compared to those obtained from our own MSC/NASTRAN finite element analyses. The correlation with the finite element numerical results was determined to verify the solution and indicated application of the solution as an approximation to free edge engineering problems is very reasonable for a broad range of practical cases involving temperature gradient effects.","PeriodicalId":326220,"journal":{"name":"Aerospace and Materials","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121541473","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

Determination of Interfacial Fracture Toughness in High Temperature Composites 高温复合材料界面断裂韧性的测定

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0475

V. T. Bechel, N. Sottos

{"title":"Determination of Interfacial Fracture Toughness in High Temperature Composites","authors":"V. T. Bechel, N. Sottos","doi":"10.1115/imece1996-0475","DOIUrl":"https://doi.org/10.1115/imece1996-0475","url":null,"abstract":"\u0000 Understanding the behavior of the fiber/matrix interface region over a range of temperatures is essential for designing composites that will have a high service temperature. In the current work, the interface failure sequence was observed during fiber pushout tests on two model composites (steel/epoxy and polyester/epoxy) with different Young’s moduli ratio and residual stress values. Novel photoelastic experiments were conducted on the model composites to measure the interfacial crack length versus load during the fiber push-out test. The data were used to better understand the failure mechanisms during the test and to determine the range of applicability of analytical and computational models of the test. Debonding was observed to occur from either the top or the bottom of the sample depending on the ratio of the elastic moduli of the fiber and matrix and the residual stress state. The pushout data from a polyester/epoxy system which debonded from the top was fit to a shear lag solution to obtain the fiber-matrix interfacial toughness (GIIc). The resulting interfacial toughness was then used to check the predicted debond length as a function of pushout force. The debond length calculated from the shear lag model was less than the measured debond length by a nearly constant 1.5 fiber radii which may correspond to the thickness of the surface effects region for polyester/epoxy.\u0000 In the future, the results of the model experiments will be used to understand the interfacial properties of two representative high temperature composites, SiC/Ti-Al-V and Al2O3/Ti-Al-V. A special high temperature apparatus was constructed for performing the push-out test at temperatures ranging from room temperature to 1000°C under vacuum. Performing interfacial measurements at elevated temperatures can be used to optimize interfacial performance at service temperatures and to better evaluate the effects of residual stresses and matrix ductility on fiber debonding and sliding.","PeriodicalId":326220,"journal":{"name":"Aerospace and Materials","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114254146","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

Durability and Damage Bahavior of 2-D and 3-D SiC/SiC Composites 二维和三维SiC/SiC复合材料的耐久性和损伤行为

Aerospace and Materials Pub Date : 1996-11-17 DOI: 10.1115/imece1996-0493

A. Parvizi-Majidi,

引用次数: 0