Recent Advances in Solids/Structures and Application of Metallic Materials最新文献

An Integrated Micro/Macro Approach for Structural Analysis of Laminate Composites With Applications to Turbine Blades 层压复合材料的微观/宏观结构分析及其在涡轮叶片中的应用

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0550

Antˆonio F. Avila

{"title":"An Integrated Micro/Macro Approach for Structural Analysis of Laminate Composites With Applications to Turbine Blades","authors":"Antˆonio F. Avila","doi":"10.1115/imece1997-0550","DOIUrl":"https://doi.org/10.1115/imece1997-0550","url":null,"abstract":"\u0000 An integrated micro/macro mechanical procedure for structural analysis of unidirectional metal matrix composites is proposed. The micromechanical analysis is performed via the Composite Cylinder Assemblage model (CCA) or the Representative Volume Element approach (RVE). The macroscopic stress-strain relation is based on a modification of the Vanishing Fiber Diameter theory (VFD), and the concept of “smeared” finite element. The fibers are considered to be linear elastic, and the matrix viscoplastic behavior is described by the Bodner and Partom model. The overall composite behavior is assumed to be elastic-viscoplastic.\u0000 Two types of material systems are employed, namely, SCS-6/Ti-15-3 and SCS-6/Tiβ21-S. Both set of material systems exhibit isotropic and/or kinematic hardening under specific conditions of temperature and loading. The proposed methodology is validated with experimental and analytical results available in the literature. After the validation process, this methodology is applied to a 3-D finite element model of a [0/90]2s SCS-6/Tiβ21-S turbine blade tip. Aerodynamic and centrifugal loading are considered acting at the same time. The turbine blade tip inelastic strain field is presented.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"149 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":"122433341","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

Strain Localization in Single Crystals: Thermodynamic Consideration 单晶中的应变局部化:热力学考虑

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0526

K. Le

引用次数: 0

Simulation of Deformation in Nial Single Crystals Nial单晶变形的模拟

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0552

Chulho Yang, Ashok V. Kumar

引用次数: 0

Yield Strength of Nitrogen Alloyed Duplex Steels: Hall-Petch Analysis and Micromechanical Predictions 氮合金双相钢的屈服强度:Hall-Petch分析和微观力学预测

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0543

E. Werner, W. Horvath, W. Prantl

{"title":"Yield Strength of Nitrogen Alloyed Duplex Steels: Hall-Petch Analysis and Micromechanical Predictions","authors":"E. Werner, W. Horvath, W. Prantl","doi":"10.1115/imece1997-0543","DOIUrl":"https://doi.org/10.1115/imece1997-0543","url":null,"abstract":"\u0000 For the prediction of the yield strength of nitrogen alloyed ferritic-austenitic duplex steels, accurate knowledge on the single phases’ yield strength and their geometrical arrangement within the duplex microstructure is required. Since the matrix-inclusion character of the phases markedly influences the yield strength σyd of duplex steels, linear models for σyd (Voigt-model) cannot serve for an accurate prediction of σyd. A non-linear rule of mixture, however, is a more sophisticated approach to calculate σyd. Micromechanical models combined with finite element computations are efficient tools to accurately predict the influence of the topology of the microstructure on σyd only if the yield strengths of the single phases are distinctly different, i.e. the yield strength ratio of ferrite to austenite ψ is larger than 2. Experiments on duplex steels show, however, a marked influence of the phase arrangement on σyd even for ψ ∼ 1. To explain this behavior a modified non-linear rule of mixture is proposed, which incorporates the in-situ yield strengths of the phases as upper and lower bounds for σyd. The discrepancy between the experiments (and their analysis) and the predictions from the micromechanical approach convincingly demonstrates the necessity to include crystallographic details such as dislocation-interface boundary interactions and misorientation and crystal structures of adjacent grains in improved micromechanical models for the yield strength of duplex steel microstructures.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"51 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":"116595476","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

The Mechanics of Hydride Formation and Embrittlement 氢化物形成和脆化的力学

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0542

J. Lufrano, P. Sofronis, H. Birnbaum

引用次数: 0

An Experimental and Numerical Analysis of Near Tip Behavior in a Multi-Phase Material 多相材料近尖端行为的实验与数值分析

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0518

C. T. Liu, G. Ravichandran

引用次数: 1

The Influence of Material Damping on Flexural Vibration of Thick Cylinders 材料阻尼对厚圆柱弯曲振动的影响

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0541

H. Hamidzadeh, D. Afolabi

{"title":"The Influence of Material Damping on Flexural Vibration of Thick Cylinders","authors":"H. Hamidzadeh, D. Afolabi","doi":"10.1115/imece1997-0541","DOIUrl":"https://doi.org/10.1115/imece1997-0541","url":null,"abstract":"\u0000 Harmonic vibrations of thick visco-elastic, infinitely long, circular cylinders subjected to boundary stresses are investigated. The cylinder is assumed to be homogeneous, isotropic, and linearly visco-elastic. The inelastic behavior of some metallic materials leads to dissipation of energy in the medium. The governing equation of motion is developed using modified theory of elastodynamics. The material damping is allowed using complex elastic moduli for the medium. Frequency responses for radial, tangential and axial displacements, as well as stresses at any location, are formulated using potential functions. The responses are computed for different circumferential and axial wave numbers for a given ratio of thickness to radius of the cylinder. The frequency range is extended to include five normalized resonant frequencies. The resonant frequency and loss factor for each mode are extracted using a circle-fit procedure in conjunction with finite difference analysis. The resonant frequency is deduced by estimating a maximum rate of sweep on the circle-fit and the loss factor is determined using selected data points on both sides of the resonance. Computation is performed to determine the effect of material loss factor on the overall damping effectiveness for the structure. Analysis was conducted by estimating resonant frequencies and modal loss factors for several circumferential and thickness to wavelength numbers.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"17 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":"131236089","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

On Dynamic Modeling of Multi-Link Spatial Manipulators With Flexible Links and Joints 具有柔性连杆和关节的多连杆空间机械臂动力学建模研究

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0536

M. Farid, S. Lukasiewicz

引用次数: 0

Thermo-Stressed State of Anisotropic Non-Homogeneous Constructive Elements 各向异性非均质构元的热应力状态

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0535

N. Pankratova

引用次数: 0

Nondestructive Evaluation of Fiberglass Reinforced Plastic Subjected to Localized Heat Damage, Using Acoustic Emission 基于声发射的玻璃钢局部热损伤无损评价

Recent Advances in Solids/Structures and Application of Metallic Materials Pub Date : 1997-11-16 DOI: 10.1115/imece1997-0529

H. Nayeb-Hashemi, P. Kisnomo, N. Saniei

{"title":"Nondestructive Evaluation of Fiberglass Reinforced Plastic Subjected to Localized Heat Damage, Using Acoustic Emission","authors":"H. Nayeb-Hashemi, P. Kisnomo, N. Saniei","doi":"10.1115/imece1997-0529","DOIUrl":"https://doi.org/10.1115/imece1997-0529","url":null,"abstract":"\u0000 Fiberglass reinforced composites are extensively used in electronic and aerospace applications due to their high specific strength. In these applications, they are often subjected to localized heat damage due to various sources such as electronic over heating, electric arching, and laser beams. In order to ensure their reliability, it is important to predict their residual properties using nondestructive evaluation techniques.\u0000 Unidirectional fiberglass composite specimens were manufactured using three layers of a fiber glass prepreg. Some of the specimens were subjected to a localized heat damage using a heated copper tip with a diameter of 12.5 mm at 360° C and other specimens were subjected to a laser beam operated at 0.64 Watts/mm2 for various exposure time. In addition, the number of laser damaged spots varied among similar specimens. The specimens were then subjected to tension tests while acoustic emission activities of specimens were collected.\u0000 The AE activity of all specimens showed three distinct regions. An early activity, followed by a relatively dormant activity period and a high exponential activity before final failure. The period of the dormant activity was independent of the contact heat duration of less than 15 minutes. However, the dormant period for the laser damaged specimens was a function of the number of laser damaged spots. The majority of the early activities for all specimens were related to mechanisms other than fiber fracture. The activity in the dormant period for contact heat damage was mainly controlled by the fiber fracture, while for the undamaged and laser damaged specimens was by the interfacial failure. This could be justified since laser damaged specimens contained numerous damaged fibers leading to a significant interfacial shear stress. The failure modes of specimens further supported this conclusion.\u0000 The state of the damage in the composite was predicted using the AE-stress delay concept.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"621 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":"133240783","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: 5