Volume 9: Mechanics of Solids, Structures, and Fluids最新文献_第8页

Use of a Trilayer Shell Model to Determine Intrinsic Stress Within Titanium-Silicon Carbonitride Coating 利用三层壳模型确定钛硅碳氮涂层内禀应力

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-87929

A. Chakraborty, F. Thompson, J. Ash, P. Ahrenkiel, F. Kustas, Robert B. Anderson

{"title":"Use of a Trilayer Shell Model to Determine Intrinsic Stress Within Titanium-Silicon Carbonitride Coating","authors":"A. Chakraborty, F. Thompson, J. Ash, P. Ahrenkiel, F. Kustas, Robert B. Anderson","doi":"10.1115/IMECE2018-87929","DOIUrl":"https://doi.org/10.1115/IMECE2018-87929","url":null,"abstract":"Thin films of titanium-silicon carbonitride (TiSiCN) with titanium adhesion layers were deposited at approximately 280°C on horizontally and vertically-mounted strips of 301-stainless steel by reactive magnetron sputtering. Considerable differences in the mid-deflections and radii of curvature between the vertical and horizontal samples were observed. Cross-sectional characterizations done on a TEM revealed a columnar growth and uniform microstructure. A finite-element model of the tri-layer sandwich structure using Mesh-Tie constraints was developed to estimate the intrinsic stress levels in the overcoat as probable functions of substrate location and orientation. The computational model in the absence of intrinsic stress was validated by analytical expressions for multilayer films. The initial stress state parameter was varied in Abaqus until consistency in curvature-values was achieved with the physical measurement obtained from an optical setup specially-constructed for this purpose. The difference in the S11/S22 principal stresses provided the intrinsic stress estimate. The calculated values of intrinsic stress were then applied to an FEA test model with fixed constraints to computationally determine the stress reduction for individual samples.","PeriodicalId":375383,"journal":{"name":"Volume 9: Mechanics of Solids, Structures, and Fluids","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123765403","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

Disappearance of Strengthened Micro Texture of Modified 9Cr-1Mo Steel Caused by Stress-Induced Acceleration of Atomic Diffusion at Elevated Temperatures 高温应力加速原子扩散导致改性9Cr-1Mo钢强化显微织构消失

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-87368

Yifan Luo, H. Miura

{"title":"Disappearance of Strengthened Micro Texture of Modified 9Cr-1Mo Steel Caused by Stress-Induced Acceleration of Atomic Diffusion at Elevated Temperatures","authors":"Yifan Luo, H. Miura","doi":"10.1115/IMECE2018-87368","DOIUrl":"https://doi.org/10.1115/IMECE2018-87368","url":null,"abstract":"The change of the lath martensitic structure in the modified 9Cr-1Mo steel was observed in the specimens after the intermittent fatigue and creep tests using EBSD (Electron Back-Scatter Diffraction) analysis. The Kernel Average Misorientation (KAM) value and the image quality (IQ) value obtained from the EBSD analysis were used for the quantitative evaluation of the change in the lath martensitic texture. It was found that the lath martensitic texture started to disappear clearly after 107–108 cycles under the fatigue loading at temperatures higher than 500°C when the amplitude of the applied stress exceeded a critical value. Similar change also appeared in the creep test. The critical value decreased monotonically with the increase of the test temperature. This microstructure change decreased the strength of the alloy drastically.\u0000 In order to explicate the dominant factors of the change quantitatively, the changes of the microstructure and the strength of the alloy were continuously measured by applying an intermittent creep test at elevated temperatures. It was found that the effective activation energy of atomic diffusion decreased drastically under the application of mechanical stress at elevated temperatures. The effective diffusion length for the disappearance was about 9 μm, and this value was much larger than the initial pitch of the lath martensitic texture of about 0.5 μm, and smaller than the average size of the initial austenite grains of about 20 μm. Therefore, the stress-induced acceleration of atomic diffusion was attributed to the disappearance of the initially strengthened micro texture. The change of the micro texture caused the drastic decrease in the yielding strength of this alloy. Finally, the prediction equation of the lifetime of the alloy was proposed by considering the stress-induced acceleration of atomic diffusion under the application of mechanical stress at elevated temperatures.","PeriodicalId":375383,"journal":{"name":"Volume 9: Mechanics of Solids, Structures, and Fluids","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130878182","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

Amplitude and Sweeping Direction Dependent Nonlinear Ultrasonic Resonance Spectroscopy for Fatigue Crack Detection 基于振幅和扫描方向的非线性超声共振光谱疲劳裂纹检测

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-86221

Yanfeng Shen, Nipon Roy, Junzhen Wang, Zixuan Liu, Danyu Rao, Wu Xu

{"title":"Amplitude and Sweeping Direction Dependent Nonlinear Ultrasonic Resonance Spectroscopy for Fatigue Crack Detection","authors":"Yanfeng Shen, Nipon Roy, Junzhen Wang, Zixuan Liu, Danyu Rao, Wu Xu","doi":"10.1115/IMECE2018-86221","DOIUrl":"https://doi.org/10.1115/IMECE2018-86221","url":null,"abstract":"This paper investigates the amplitude and sweeping direction dependent behavior of nonlinear ultrasonic resonance spectroscopy for fatigue crack detection. The Contact Acoustic Nonlinearity (CAN) and the nonlinear resonance phenomena are illuminated via a reduced-order bilinear oscillator model. Unlike conventional linear ultrasonic spectroscopy, which would not change its pattern under different amplitudes of excitation or the frequency sweeping direction, the nonlinear resonance spectroscopy, on the other hand, may be noticeably influenced by both the wave amplitude and the loading history. Both up-tuning and down-tuning sweeping active sensing tests with various levels of excitation amplitudes are performed on a fatigued specimen. Short time Fourier transform is adopted to obtain the time-frequency features of the sensing signal. Corresponding to each excitation frequency, a nonlinear resonance index can be established based on the amplitude ratio between the superhamronic, the subharmonic, the mixed-frequency response components and the fundament frequency. The measured nonlinear resonance spectroscopy for a certain amplitude and frequency sweeping direction can be readily used to establish an instantaneous baseline. The spectroscopy of a different amplitude or frequency sweeping direction can be compared with such an instantaneous baseline and a Damage Index (DI) is obtained by measuring the deviation between the two spectra. Experimental investigations using an aluminum plate with rivet hole nucleated fatigue cracks are performed. A series of nonlinear spectroscopies are analyzed for both the pristine case and the damaged case. The spectral features for both cases are obtained to demonstrate the proposed fatigue crack detection methodology which may find its application for structural health monitoring (SHM). The paper finishes with summary, concluding remarks, and suggestions for future work.","PeriodicalId":375383,"journal":{"name":"Volume 9: Mechanics of Solids, Structures, and Fluids","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128565525","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

Influence of Strain States on the Thermal Transport Properties of Single and Multiwalled Carbon Nanostructures 应变状态对单壁和多壁碳纳米结构热传递性能的影响

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-88620

Sushan Nakarmi, V. Unnikrishnan

{"title":"Influence of Strain States on the Thermal Transport Properties of Single and Multiwalled Carbon Nanostructures","authors":"Sushan Nakarmi, V. Unnikrishnan","doi":"10.1115/IMECE2018-88620","DOIUrl":"https://doi.org/10.1115/IMECE2018-88620","url":null,"abstract":"The increasing demand for system miniaturization and high power density energy produces excessive thermal loads on electronic devices with significant mechanical strain. Carbon Nanotubes (CNTs) based devices are found to have excellent thermal transport properties that makes them attractive for thermal management of these miniaturized nano-electronic devices under extreme environments. These conductive nanostructure (carbon nanotubes, graphene, etc.) are often embedded in polymers or other high-strain alloys (the matrix phase), and are used as bridging materials for conductivity (electrical and thermal) with strain resiliency. The effect of strain on the thermal transport properties of these nanostructures have often been overlooked and will be the focus of this work. The thermal conductivity of the nanostructure is obtained in LAMMPS using the Heat-Bath method, which is a reverse non-equilibrium molecular dynamics (RNEMD) simulation strategy. In RNEMD, constant amount of heat is added to and removed from hot and cold regions and the resultant temperature gradient is measured. The effect of strain on the thermal conductivity of the single and multiwalled nanostructures of various configurations will be discussed with specific emphasis on the phonon density of states of nanotubes at different strain states.","PeriodicalId":375383,"journal":{"name":"Volume 9: Mechanics of Solids, Structures, and Fluids","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133183506","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

Mesoscale Material Strength Characterization for Use in Fracture Modeling 断裂建模中尺度材料强度表征

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-88249

K. Acton, B. Bahmani, R. Abedi

引用次数: 1

Heat Built Up During Dynamic Mechanical Analysis (DMA) Testing of Rubber Specimens 橡胶试样动态力学分析(DMA)测试过程中产生的热量

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-88627

R. Esmaeeli, Ashkan Nazari, Haniph Aliniagerdroudbari, S. R. Hashemi, Muapper Alhadri, Waleed Zakri, Siamak Farhad

引用次数: 5

Mechanical Performance Analysis of ULTEM 9085 in a Heated, Irradiated Environment ULTEM 9085在加热辐照环境中的力学性能分析

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-88181

M. B. Ng, S. Brennan

{"title":"Mechanical Performance Analysis of ULTEM 9085 in a Heated, Irradiated Environment","authors":"M. B. Ng, S. Brennan","doi":"10.1115/IMECE2018-88181","DOIUrl":"https://doi.org/10.1115/IMECE2018-88181","url":null,"abstract":"This paper investigates the thermal and radiation performance of 3D-printed ULTEM materials following ASTM standard D638. ULTEM is a thermoplastic in the polyetherimide (PEI) family that is regularly used as a high-grade material for 3D printing. This material has similar properties to polyether ether ketone (PEEK), which is another thermoplastic that has strong mechanical properties at elevated temperature conditions. While PEEK has stronger mechanical properties, ULTEM is significantly more cost efficient to acquire and process via 3D printing. Also, most 3D printers are unable to utilize PEEK because of the significantly higher temperature requirements this material imposes on a 3D printer.\u0000 This work is motivated by the need to rapidly deploy robotic inspection systems within a nuclear canister environment, which exposes the material to temperatures up to 170°C (340°F), and radiation levels of 270 Gy/hr (27 krad/hr), which are significantly beyond that of conventional 3D-printed parts. The design analysis was performed via an experiment consisting of three treatment groups of dogbone ULTEM test pieces. After tensile testing all of the pieces, the material properties were compared to those of the control group.\u0000 These results allow manufacturers to select a more cost-effective material to build parts to operate in such a harsh high-temperature, high-radiation environment, which could include applications in both space systems and nuclear inspection robotics. Specifically, the results were used to guide the development of a robust robotic inspection system for the Nuclear Energy University Program (NEUP) by replacing complex parts with easily-fabricated 3D-printed ULTEM pieces.","PeriodicalId":375383,"journal":{"name":"Volume 9: Mechanics of Solids, Structures, and Fluids","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124428112","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

Statistical Volume Elements for the Characterization of Angle-Dependent Fracture Strengths 角度相关断裂强度表征的统计体积元

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-88257

J. Garrard, R. Abedi, P. Clarke

{"title":"Statistical Volume Elements for the Characterization of Angle-Dependent Fracture Strengths","authors":"J. Garrard, R. Abedi, P. Clarke","doi":"10.1115/IMECE2018-88257","DOIUrl":"https://doi.org/10.1115/IMECE2018-88257","url":null,"abstract":"The fracture response of rock, a quasi-brittle material, is very sensitive to its microstructural defects. Herein, we use statistical volume elements (SVEs) to characterize rock fracture strength at the mesoscale, based on the distribution of microcracks at the microscale. The use of SVEs ensures that the material randomness is maintained upon “averaging” of microscale features. Certain fracture strengths, such as uniaxial tensile strength, uniaxial hydrostatic strength, shear strength, and uniaxial compressive strength, are obtained and characterized for different angles of loading. Thus, a material with anisotropic fracture strength can be characterized. Statistics of the characterized strengths are analyzed, as well as their auto- and cross-correlation functions of these random fields to shed light on the length scales, relative to the volume element size, at which homogenized properties vary. While crack interaction is not included, the analysis provides insight on the distribution and correlation of different strengths. Finally, the asynchronous spacetime discontinuous Galerkin method is used for macroscopic fracture analyses of two rock domains homogenized by SVEs.","PeriodicalId":375383,"journal":{"name":"Volume 9: Mechanics of Solids, Structures, and Fluids","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131080533","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

Study of the Effect of Large Deformation Through a Finite Deformation Based Constitutive Model for Metallic Glasses 基于有限变形本构模型研究大变形对金属玻璃的影响

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-86063

S. Kulkarni, T. Bhandakkar

{"title":"Study of the Effect of Large Deformation Through a Finite Deformation Based Constitutive Model for Metallic Glasses","authors":"S. Kulkarni, T. Bhandakkar","doi":"10.1115/IMECE2018-86063","DOIUrl":"https://doi.org/10.1115/IMECE2018-86063","url":null,"abstract":"A thermodynamically consistent constitutive model of metallic glass is presented by extending the infinitesimal deformation model of Huang et al. [Huang, R., Suo, Z., Prevost, J. H., and Nix,W. D., 2002.Inhomogeneous deformation in metallic glasses,J. Mech. Phys. Solids, 40, 1011–1027] to finite deformation. The underlying theory behind the model is the free volume theory with free volume concentration as the order parameter affected through the processes of diffusion, annihilation and creation. The main assumptions of the model include multiplicative decomposition of deformation gradient and additive decomposition of free energy. The former comprises of elastic, inelastic dilatational component associated with excess free volume concentration and isochoric plastic part while the latter consists of contributions from elastic deformation and free volume concentration. The plastic part evolves according to Mises-theory and the local free volume concentration. Homogeneous simple shear is the model problem solved using the present model and compared with the infinitesimal deformation theory to examine the effect of large deformation on stresses in metallic glasses.","PeriodicalId":375383,"journal":{"name":"Volume 9: Mechanics of Solids, Structures, and Fluids","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123206430","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

Effect of Graphene on Mechanical Performance of Pin-Loaded Circular Hole in Laminated Composites 石墨烯对层合复合材料针脚加载圆孔力学性能的影响

Volume 9: Mechanics of Solids, Structures, and Fluids Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-87566

O. Aluko

引用次数: 0