Improved Moment Strength Prediction of Composite Steel Plate Girders in Positive Bending

This paper contains an alternate method for the calculation of the predicted positive bending moment capacity of composite steel girders. The 2000 interim version of the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design Bridge Design Specifications has extended the applicability of the provisions for the design of composite plate girders in positive bending to include 485 MPa high performance steel. Observations made during numerical studies performed in conjunction with this extension demonstrated a need for a more comprehensive study encompassing a larger and more diverse set of parameters. This paper provides a summary of the analytical and experimental work that was carried out to develop provisions for predicting the ultimate strength and assuring the ductility of composite girders constructed using 250, 345, or 485 MPa steels. The new provisions outlined in this paper are more accurate and require less calculation. The recommended equations only require calculation of the plastic moment capacity, while current AASHTO Specification provisions require the calculation of both plastic and yield moment capacities of the section.     

High Performance Steel: Research Front—Historical Account of Research Activities

This paper provides a summary of the major research studies conducted or being conducted in the U.S., to address design issues related to use of high performance steel (HPS) in bridge construction. Emphasis of the paper is on the work related to HPS-485W steel, which has specified minimum yield strength of 485 MPa (70 ksi). Design issues that are addressed in this paper include (1) flexural capacity of compact and noncompact HPS sections in negative bending; (2) issues related to ductility of HPS composite girders in the positive sections (this section presents a simplified ductility check for composite plate girders); (3) tensile ductility of HPS plates; (4) shear capacity of the hybrid steel plate girders; (5) live load deflections; and (6) brief overview of the work that is underway to develop innovative bridge configurations capable of incorporating the advantages of HPS.     

APA approved doctoral programs in clinical and in counseling psychology, 1962.

"On recommendation of the Committee on Evaluation, the Education and Training Board, with the concurrence of the Board of Directors of the American Psychological Association has approved the doctoral programs in clinical psychology and in counseling psychology that are conducted by the institutions listed." 60 institutions are in the clinical psychology list; 8 of these have received interim approval while the others have full approval. 25 institutions are in the counseling psychology list; 2 of these have interim approval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Doctoral training programs in clinical psychology and in counseling.

"On recommendation of the Committee on Evaluation, the Education and Training Board with the concurrence of the Board of Directors of the American Psychological Association has approved the doctoral training programs in clinical and in counseling psychology that are conducted by the institutions listed." 56 institutions are in the clinical psychology list; 12 of these have received interim approval while the others have full approval. 27 institutions are in the counseling psychology list; 4 of these have interim approval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

APA approved doctoral programs in clinical and in counseling psychology, 1963.

"On recommendation of the Committee on Evaluation, the Education and Training Board, with the concurrence of the Board of Directors of the American Psychological Association, has approved the doctoral programs in clinical psychology and in counseling psychology that are conducted by the institutions listed." 61 institutions are in the clinical psychology list; 7 of these have received interim approval while the others have full approval. 24 institutions are in the counseling psychology list; 2 of these have interim approval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Doctoral training programs in clinical psychology and in counseling psychology.

"On recommendation of the Committee on Evaluation, the Education and Training Board with the concurrence of the Board of Directors of the American Psychological Association has approved the doctoral training programs in clinical psychology and in counseling psychology" conducted by the institutions listed. Under "Doctoral Programs in Clinical Psychology" 57 institutions are listed; 7 of these have interim approval while the others are undifferentiated by any rating. Under "Doctoral Programs in Counseling Psychology" 24 institutions are listed; 1 of these has interim approval. From Psyc Abstracts 36:02:2AM12A. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Doctoral training programs in clinical psychology and in counseling psychology.

"On recommendation of the Committee on Evaluation, the Education and Training Board with the concurrence of the Board of Directors of the American Psychological Association has approved the doctoral training programs in clinical psychology and in counseling psychology" conducted by the institutions listed. Under "Doctoral Programs in Clinical Psychology" 52 institutions are listed; 10 of these are indicated as having received interim approval while the others are undifferentiated by any rating. Under "Doctoral Programs in Counseling Psychology" 26 institutions are listed; 7 of these have interim approval. The institutions listed "have been reported to the United States Public Health Service, to the Veterans Administration, and to The Surgeon General's Office, Department of the Army as conducting at the present time approved programs of doctoral training in areas indicated." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

不锈钢/碳钢耐蚀海水带肋钢筋轧制复合工艺

摘要：海洋工程用带肋钢筋要求有耐氯离子腐蚀能力，但选用双相不锈钢生产成本过高，不锈钢 碳钢轧制复合钢筋则可兼顾耐蚀性和低成本。覆层采用2205不锈钢，基材为低合金钢20MnSi，用有限元方法模拟钢筋的热轧复合过程，分析轧制过程尤其是成品孔中轧件的变形规律。有限元仿真发现，矩形组合坯料无孔型轧制时，其角部复合困难，而成品孔轧制时，钢筋横肋根部的应变最大，覆层在此位置减薄显著，应选择合适的复合坯覆层厚度。在实验室采用焊接、真空处理和热轧方法制备了直径为16mm的复合钢筋，屈服强度为485MPa，抗拉强度为701MPa，断后伸长率约为37.1%，复合界面剪切强度为317.5MPa。复合钢筋呈良好的冶金结合，Fe和Cr的扩散层厚度约为40μm。该工艺生产的复合带肋钢筋成本较不锈钢降低50%以上。     

A New Nonmetallic Inclusion Rating Method by Positive Use of Hydrogen Embrittlement Phenomenon

A new inclusions rating method using hydrogen embrittlement of a tensile test specimen is proposed. This method is essentially based on the statistics of extremes for inclusion rating where the maximum inclusion size is determined by simple tensile testing of a hydrogen-precharged (H-precharged) specimen. Tensile tests were conducted using two bearing steels (SAE52100 HV 346, HV 447, HV 559, HV 611, HV 678 and ASTM-A485-1 HV 706, HV 715) and one spring steel (SAE5160, HV 651). Fatigue tests were conducted using SAE52100 bearing steel (HV 682). All H-precharged tensile specimens (SAE52100, ASTM-A485-1 and SAE5160) were fractured from internal inclusions except the SAE52100 tensile specimens with a Vickers hardness of HV 346. It was confirmed that the distribution of extreme values of inclusion sizes obtained by SAE52100 tensile testing with H-precharged specimens coincided with those obtained by SAE52100 fatigue testing. From these results, it is presumed that the inclusion rating method by fatigue testing can be replaced by simple tensile testing with H-precharged specimens. The proposed method is more convenient and reliable than other existing inclusion rating methods, i.e., fatigue testing and optical microscopy. The proposed method can be applied to specimens with a Vickers hardness of higher than HV 447.     

Directional dendritic solidification of a composite slurry: Part II. Particle distribution

The present work attempts to form an understanding of particle distribution during dendritic solidification of a composite slurry. It is shown that the magnitude and nature of the forces involved between a foreign particle and a growing dendrite are distinctly different from those during plane front solidification. A particle distribution map, based on theoretically evaluated forces, is proposed to predict the conditions under which engulfment, entrapment, or pushing of particles occurs during dendritic solidification. Directional solidification experiments have been conducted to study particle distribution, and comparison of these results with theoretical predictions based on the map agree well with a large number of experimental observations reported to date.     

Repair of Wood Piles Using Prefabricated Fiber-Reinforced Polymer Composite Shells

An effective method for combined environmental protection and structural restoration of wood piles in waterfront facilities is not available. The objective of the study presented in this paper is to survey the available methods for wood pile protection and structural restoration with the intent of developing an effective method. In addition to reviewing the available repair methods, a field inspection of a harbor in Maine was conducted to assess existing technologies. A wood pile repair method that utilizes bonded fiber-reinforced polymer (FRP) composite shells and a grouting material is proposed. Fiber, resin, adhesive, coating, and grouting materials are systematically analyzed to deliver the required system performance. Two fabrication methods for the FRP composite shells are discussed based on the experience gained in the fabrication of laboratory prototypes. Then a step-by-step procedure amenable for field installation is proposed, and a preliminary cost analysis is conducted to assess the feasibility of the proposed system.     

钽钢复合板钽覆层的焊接工艺研究

对钽钢复合板的钽覆层采用敷设盖板的方式焊接，研究了直流氩弧焊与交流脉冲氩弧焊两种焊接工艺对钽钢复合板焊接质量的影响。结果表明，直流氩弧焊的焊接热影响区较宽，焊接熔深为1～1．5mm，在钢与过渡金属层之间形成了中间夹层；交流脉冲氩弧焊的焊接热影响区较窄，焊接熔深为0．5～1mm，复合板焊接质量较好。与直流氩弧焊相比，交流脉冲氩弧焊焊接参数范围较宽，对焊工技能的要求相对较低，可实现连续化生产，因此更适合用于钽钢复合板钽覆层的焊接。     

Simplified Moment Redistribution of Hybrid HPS 485W Bridge Girders in Negative Bending

Simplified moment redistribution procedures based on shakedown have recently been approved by AASHTO LRFD Bridge Design Specifications (AASHTO 2004). These procedures are currently only applicable for homogeneous girders, and thus, the objective of this study is to evaluate whether these procedures can be further applied for hybrid HPS 485W girders. A parametric study is carried out using validated three-dimensional finite-element (FE) analyses to study the inelastic behavior of hybrid HPS 485W girders in negative bending for this purpose. The effective plastic moments obtained from the FE studies are compared with those from the proposed prediction equations, where good correlation is observed. A design example of a three-span slab-on-girder bridge with hybrid HPS 485W girders using both elastic design and the simplified moment redistribution procedures is also presented, where it is shown that the use of moment redistribution procedures results in a negative bending section that is 13% lighter than the corresponding elastic design.     

Municipal Solid Waste Slope Failure.?II: Stability Analyses

Analyses are presented to investigate the case of a large slope failure in a municipal solid waste (MSW) landfill that developed through the underlying native soil. The engineering properties of the waste and native soil are described in a companion paper by Eid et al. (2000). Some of the conclusions from this case history include (1) native colluvial∕residual soils in the Cincinnati area underlying MSW can mobilize a drained shear strength less than the fully softened value without recent evidence of previous sliding; (2) strain incompatibility and progressive failure can occur between MSW and underlying materials and cause a reduction in the mobilized shear strength; (3) a stability evaluation of interim slopes, especially when the slope toe will be excavated, blasting will be occurring, and waste placement continues at the top of slope, should be conducted, even though it may not be required by regulations; and (4) the reappearance of cracking at the top of an MSW landfill slope is probably an indication of slope instability and not settlement.     

Disclosure of negative information in letters of recommendation: Writers' intentions and readers' experiences.

Do letters of recommendation contain accurate information about applicants for psychology internships? A 2-part national survey was conducted to investigate how writers of letters of recommendation for applicants for internships in psychology deal with negative characteristics of applicants when they are thought to exist. One hundred seventy-five psychologists who had recently written letters of recommendation generally claimed in their responses that they would disclose information about some negative characteristics. In contrast, a 2nd sample of 116 psychologists who had recently read letters of recommendation indicated in their responses that negative characteristics are infrequently described in letters of recommendation. Therefore, one cannot presume that letters fully disclose applicants' limitations and problems, and mechanisms to enhance disclosure are needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Magnetically sensitive precision-alloy components

Theoretical and experimental research on magnetically soft amorphous microwire, strip, and composite wire with giant magnetic impedance, conducted between 2000 and 2010 at the Institute of Theoretical and Applied Electrodynamics (Russian Academy of Sciences), Lomonosov Moscow State University, Troitsk Institute of Innovative and Thermonuclear Research, and Bardin Central Research Institute of Ferrous Metallurgy, is briefly reviewed. The goal of this research is to create magnetic-field converters with high sensitivity and resolving power. The materials developed are used to produce prototype sensors of weak magnetic fields and their applicability is evaluated.     

基于关联关系的仿真模型实时智能推荐方法

当全球导航卫星系统(global navigation satellite system,GNSS)分布式仿真环境中共享的模型数量非常多时,检索模型和配置仿真任务将成为一个比较复杂的工程.为提高仿真模型选取和仿真任务配置的效率,设计了一套针对GNSS分布式仿真环境中仿真模型的实时智能推荐方法,方法中首先定义了模型关联关系和接口形状的概念,然后提出了一种条件约束下的频繁模式树(FP-tree)结构,并从理论上分析了该结构在检索任务量方面的减少程度,设计并推导了模型关联关系度的计算方法,以及整套智能推荐方法的运行流程.推荐方法在GNSS分布式仿真环境中进行了仿真验证,仿真结果与传统智能推荐方法做对比分析,分析结果表明,该方法针对仿真模型推荐时运行时间短,推荐结果准确度高,能够实时为用户推荐合适的模型.     

Influence of graphite and copper in mechanical properties of aluminum silicon alloy

The present work deals with the mechanical behaviour of the Al-Si-Cu/graphite composite at different strain rates. Stir casting technique was used to fabricate the Al-Si alloy and composite. In order to improve the wettability of graphite with the alloy, graphite particulates were ball milled with Copper and preheated to 400°C. The uniaxial tensile tests were conducted at various strain rates in the range of 10^?4s^?1 to 10^?2s^?1. The ultimate tensile strength of the composite was higher than that of the alloy for all strain rates. The hardness of the composite was also better than that of alloy. The elongation of the alloy was more than that of composite for all strain rates. The uniform distribution of graphite and silicon particles were observed from the microstructure. The fracture mode of alloy and composite were analyzed.     

0.9C-9Mn-2Cr-Mo中锰耐磨钢的冲击滚动复合磨损性能

通过M2000多功能摩擦磨损试验机研究0. 9C-9Mn-2Cr-Mo中锰钢和Hardax400(0. 22C-1.6Mn-1.4Cr-Mo)以及Hardex500(0.27C-1.0Mn-0.94Cr-Mo)耐磨钢的冲击和滚动复合摩擦磨损性能,并利用XRD、SEM和TEM等分析了组织转变及磨损机理。实验结果表明,热轧中锰钢比Hardox马氏体耐磨钢表现出更好的抗冲滚磨料磨损性能。中锰钢冲滚磨损表面存在厚度达1000μm的硬化层,最高显微硬度达HV490,洛氏硬度达HRC53。中锰钢磨损机制以凿削破坏为主,伴随局部的疲劳剥落破坏;位错强化、形变孪晶和马氏体相变是中锰钢硬化和抗磨损性能改善的主要原因。     

控制总量 调整结构 增强实力 为建设钢铁强省而努力奋斗──在2000年河北省冶金工作会议上的讲话(摘要)

总结了1999年河北省冶金工业取得的主要成绩，分析了2000年河北冶金工业面临的形势，提出了2000年的奋斗目标，并为实现奋斗目标做了工作部署。