ASTM special technical publications最新文献_第9页

Transition fracture toughness testing with notched round bars (NRB) 缺口圆棒(NRB)过渡断裂韧性试验

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP14806S

Christopher D. Wilson, J. Landes

引用次数: 3

Fracture Parameters of Surface Cracks in Compressor Disks 压缩机盘片表面裂纹的断裂参数

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP14811S

W. Zhuang, B. J. Wicks

{"title":"Fracture Parameters of Surface Cracks in Compressor Disks","authors":"W. Zhuang, B. J. Wicks","doi":"10.1520/STP14811S","DOIUrl":"https://doi.org/10.1520/STP14811S","url":null,"abstract":"The elastic and elastic-plastic fracture mechanics parameters of surface cracks in compressor disks of aircraft engines are evaluated using both the finite element method and the weight function method. First, a three-dimensional finite element model of a low-pressure compressor disk containing a surface crack at the snap radius is developed. The stress intensity factor distributions along the surface crack front with various crack shapes and sizes in the disk under a typical engine operation condition are calculated. Then, the effect of biaxial stresses on the stress intensity factor of a crack emanating from a tie bolt hole in a representative compressor disk is investigated using the weight function approach. Emphasis is given to determining the effect of the bolt hole plastic zone on the fracture parameters when the compressor disk is highly loaded. Finally, a new theoretical model for the estimation of the fracture parameters of a through-thickness crack in the web region is proposed using a definition of local biaxial stress ratio. The studies show that the developed model can provide better estimation of the plastic zone size and the crack-tip opening displacement than those existing models.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89826463","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

Using Ecological Site Scoping to Evaluate Contaminant Transport Pathways 利用生态场地范围评估污染物的运输途径

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP14419S

R. Ryti, E. Kelly

{"title":"Using Ecological Site Scoping to Evaluate Contaminant Transport Pathways","authors":"R. Ryti, E. Kelly","doi":"10.1520/STP14419S","DOIUrl":"https://doi.org/10.1520/STP14419S","url":null,"abstract":"Los Alamos National Laboratory (LANL) has developed an ecological screening evaluation process that emphasizes the development and testing of an ecological exposure and transport pathway site conceptual model. LANL developed this screening approach in partnership with personnel from the State of New Mexico regulatory authority (the New Mexico Environment Department or NMED). A key part of the screening evaluation process is the completion of an innovative ecological scoping checklist. This checklist helps to (1) determine if complete pathways to ecological receptors exist; (2) determine how the impacted media should be aggregated spatially for screening, establishing the functional/operational boundaries of the assessment; and (3) gather information to develop the site conceptual model (SCM). The SCM includes contaminant sources, dominant transport pathways and exposure routes, and potential receptors. The scoping checklist consists of a series of questions and placeholders for field notes, which are intended to guide the risk assessor in developing the SCM, and provide the decision-makers with consistent information on receptors, potential transport pathways and potential exposure pathways. This paper summarizes the LANL/NMED scoping checklist and gives examples of its application at the LANL Environmental Restoration (ER) sites.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73018589","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

Quality Control of Earth Fills Using Time Domain Reflectometry (TDR) 用时域反射法(TDR)控制填土质量

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP15291S

Chih‐Ping Lin, S. I. Siddiqui, W. Feng, V. Drnevich, R. Deschamps

引用次数: 10

Early stage fatigue damage characterization in aluminum alloys and stainless steels with Meandering Winding Magnetometer technology 用弯曲绕组磁强计技术表征铝合金和不锈钢的早期疲劳损伤

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP13418S

V. Weiss, N. Goldfine, M. Natishan

引用次数: 3

On the accuracy of measurement and calibration of load signal in the instrumented Charpy impact test 仪器夏比冲击试验中载荷信号测量和校正的准确性

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP14395S

Toshiro Kobayashi, Naoya Inoue, S. Morita, H. Toda

引用次数: 3

Biaxial Fatigue of stainless steel 304 under irregular loading 不锈钢304在不规则载荷下的双轴疲劳

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP14795S

K. S. Kim, Bl Lee, J.C. Park

引用次数: 17

Fracture mechanics validity limits and physical evidence of constraint in fracture 断裂力学有效性、极限和断裂约束的物理证据

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP13399S

D. Lambert, H. Ernst

{"title":"Fracture mechanics validity limits and physical evidence of constraint in fracture","authors":"D. Lambert, H. Ernst","doi":"10.1520/STP13399S","DOIUrl":"https://doi.org/10.1520/STP13399S","url":null,"abstract":"The consideration of fracture behavior should be a matter of vital concern in current design efforts. Many materials exhibit grossly different behavior when discontinuities are present in the structure. These may be inherent in the material or may stem from poor manufacturing, handling, and/or design practices. Inclusion of fracture behavior in the design models is the subject of fracture mechanics. Ultimately, a knowledge of fatigue and fracture becomes very important in avoiding disaster. This paper is written with two primary purposes: to characterize the physical nature of fracture, and to dramatize the need to characterize the central flat fracture differently from the surface, shear fracture. To this end, the contents of the paper are organized as follows: (1) validity limits of fracture mechanics: this information was originally developed for the purpose of extracting similar fracture data and will be used here to help characterize bulk constraint effects and to establish the existence of the surface effect; (2) analysis of crack face displacements of planar specimens subjected to loads: this includes actual crack-, separation-, and stretch-profiles; and (3) consideration of three-dimensional fracture in light of the existence of two distinct fracture zones that exhibit different failure mechanisms; for this purpose, G and J as a functitin of depth below surface are discussed, as well as several constraint factors as a function of depth.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86922425","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

Compaction and Performance of Loess Embankments 黄土路堤的压实与性能研究

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP15283S

Liming Zhang, Jia-Yang Du, T. Hu

引用次数: 0

The Role of Oxidation on the Thermo-mechanical Fatigue of Timetal 21S Matrix Composites 氧化对Timetal - 21S基复合材料热机械疲劳的影响

ASTM special technical publications Pub Date : 2000-01-01 DOI: 10.1520/STP15262S

O. Jin, W. Johnson

{"title":"The Role of Oxidation on the Thermo-mechanical Fatigue of Timetal 21S Matrix Composites","authors":"O. Jin, W. Johnson","doi":"10.1520/STP15262S","DOIUrl":"https://doi.org/10.1520/STP15262S","url":null,"abstract":"Isothermal fatigue tests were performed on unnotched quasiisotropic SCS-6/Timetal 21S (Ti-15Mo-2.6Nb-3Al-0.2Si) composites at room temperature, 400°C and 500°C with various hold times (0, 1 and 10 seconds). The specimen tested at 500°C showed significant oxidation, especially along the grain boundaries. In addition, there were changes in various physical properties of the composites at elevated temperatures: oxidation, phase transformation, viscoplastic flow of matrix, and interface reaction. The measurement of oxide thickness of both with and without load indicated that the oxidation of the matrix material was more severe with applied load than without load for the same amount of exposure time. Simple spectrum loading tests were conducted to examine the effect of test temperature on the formation of oxidation and its influence on the damage accumulation in the composites. Different numbers of applied cycles per block were used: n 1 and n 2 = 10, 100, and 1000 cycles. The change in temperature along with stress acted as thermal cycle that further introduced damages into the composites and reduced their life. As the number of applied cycles increased, the failure life of the composites was increased. The small number of cycles per block showed a shorter life due to more frequent changes in temperature level.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89527680","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