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报告分类:外文技术报告

  • 3091.多金属护甲应用中牺牲性涂层对10.9级紧固件的腐蚀行为

    [金属制品业,化学原料和化学制品制造业] [2014-07-26]

    This experiment examined the effect of accelerated corrosion testing and immersion testing on 13-mm-grade 10.9 bolts. A matrix containing chemical agent resistant coating (CARC) and bare Al 5059, as well as Rolled Homogeneous Armor (RHA) steel plates with CARC that are each bolted together with one bolt of each pretreatment system were subjected to GM9540P in an attempt to evaluate the corrosion prevention properties of each selected coating and pretreatment while simulating the practical applications of bolt-on armor. Five candidate finishes (zinc plating in accordance with the American Society for Testing and Materials ASTM)-B 633 with hexavalent chromium conversion coating as control were tested in replicate sets of assemblies. In the immersion phase of testing, each bath was heated to 75 F, and the salt solution was agitated in order to prevent stagnation and ensure equal heating. Testing was completed over 500 h, with visual and potential inspections at 1, 2, 4, 8, and 24 h, and every subsequent 24 h thereafter. Accelerated corrosion testing was programmed for 120 cycles GM9540 with inspection for corrosion creep at 20 cycle intervals. Corrosion creep in this experiment was defined visually as frosting for the onset of corrosion and red rust in the percentage of the fastener affected yielding separate observations. Each of the pretreatments are assessed and compared in terms of corrosion inhibition.
    关键词:钢铁;螺栓;涂料;腐蚀;紧固件
  • 3092.海洋重力式结构基础设计的概率研究

    [黑色金属冶炼和压延加工业] [2014-07-26]

    Gravity structures play a prominent role today in North Sea oil development.These structures are not supported by piles as are most ocean structures but rather sit directly on the ocean bottom, and depend on their foundation geometries and large weights to resist severe environmental loadings.A number of structural and foundation configurations have been proposed; however,attention will be restricted in this discussion to a general configuration typical of the most prominent structures being constructed at present (1975). An example of a gravity structure is illustrated in Fig. 1. The structure foundation consists of a large caisson placed directly on the unprepared seabed surface.The deck is supported by large columns extending from the caisson.Various combinations of steel and reinforced concrete have been proposed, but the majority of structures are being constructed almost entirely of reinforced and prestressed concrete.
    关键词:钢铁;重力式结构;石油;钢筋混凝土
  • 3093.限元仿真吲临时混凝土锚屏障

    [黑色金属冶炼和压延加工业] [2014-07-26]

    Portable Concrete Barriers (PCBs) are used to redirect errant vehicles to keep them passing to opposing lanes and to ensure safety of the people and any objects behind the barriers. In the state of Indiana, increments to the PCBs, such as L-Shape steel plates, have been applied to enhance the safety performance of these barriers. In this study, Finite Element (FE) analyses are performed to evaluate the safety performance of PCBs with and without the increments and get thorough information about the increments applied. A full-scale crash test (INDOT, 2001) was executed for an impact to the PCBs with a 2000 kg pickup truck at an angle of 25 degrees and an initial velocity of around 100 km/hr in accordance with National Cooperative Highway Research Program (NCHRP) Report 350 guidelines for Test Level 3 safety performance. Aforementioned full-scale crash test data are used to validate the FE model constructed. Roadside Safety Verification and Validation Program (RSVVP) was used to compare the crash test and FE model results quantitatively. Validating the results of the initial FE Model leaded the way in confidence to implement the increments in the following FE Models.
    关键词:钢铁;有限元法;碰撞试验;钢板
  • 3094.防腐螺旋肋镀铝管

    [黑色金属冶炼和压延加工业] [2014-07-26]

    关键词:钢铁;钢管;防腐;排水
  • 3095.考虑系统成员强度变异性影响的冗余钢结构系统评估

    [黑色金属冶炼和压延加工业] [2014-07-26]

    In the present study,the failure of basic redundant steel structural systems is investigated.By considering that each member of the system has brittle,semi-brittle,or perfectly plastic properties,the statistical behavior of perfectly brittle systems,semi-brittle systems,perfectly plastic and combination systems are evaluated,and the effects of the coefficient of variation (CoV) of members on the systems are investigated.Uncorrelated strengths with the same mean are considered for the system elements.By using the Monte Carlo simulation (MCS) method,maximum strength,yield strength and residual strength of the redundant steel structural systems are evaluated.The CoV of member strength is an essential parameter for statistical assessment of steel structural systems.In this study,the strength is defined random variable a selected normal distribution represents the random variable,for the member strength.The deformation capacity of the member is strongly depends to the characteristics of member strength,but the post failure factor has deterministic values,only for the combination system.The post failure factor is a random variable that represents the uncertainty,uniform distribution is selected to represents random variable,in combination system post failure factor.
    关键词:钢铁;单调荷载;强度;变形
  • 3096.全面挖掘支持螺旋钉无水泥土钉的初始性能和建设

    [建筑业] [2014-07-26]

    Spiralnails are hollow steel pipes extruded and twisted to form a square helical shape. They are driven rather than drilled, and thus they do not require cement grout to develop a bond with the soil, and provide immediate internal stability improvement to a soil mass. Because effective and economical designs require an improved understanding of individual and group spiralnail behavior, a 6-m (20-ft) tall, top-down vertical excavation was constructed using spiralnails in a well-characterized, engineered fill. The spiralnail reinforcement design used existing soil nail design methods to achieve an acceptable factor of safety using nail lengths and spacing comparable to those common for a conventional grouted nail design. The objective of the project was to measure the performance of the spiralnail reinforced soil mass in order to evaluate the applicability of existing soil nail design methods to spiralnail design. The paper describes the design, construction, soil characterization and properties, instrumentation, and presents the measured load-displacement behavior of the spiralnails and observed deformation of the reinforced soil mass. A preliminary analysis of load-displacement data is presented, and calculated spiralnail equivalent bond stress values are provided. Based on the measured deformations and using an empirical correlation, the spiralnail-reinforced soil mass performance is compared to a grouted nail-reinforced soil mass.
    关键词:钢铁;钢管;灌浆;水泥
  • 3097.金属加筋土墙的LRFD校准

    [黑色金属冶炼和压延加工业] [2014-07-26]

    The paper is focused on key points and lessons learned from LRFD calibration of simple limit state functions for the internal stability of metallic reinforced soil walls. The example used in the paper is the ultimate pullout limit state for ribbed steel strip reinforced mechanical stabilized earth (MSE) walls and a single load due to soil self-weight plus a permanent surcharge load. The paper demonstrates how load and resistance measurements from instrumented walls and physical pullout tests can be used to generate bias values. Bias statistics are then used to: a) improve the accuracy of underlying deterministic models used to compute nominal load and resistance values; b) remove hidden dependencies; c) select load factors; and, d) calculate resistance factors to meet an acceptable probability of failure. While the paper is focused on the pullout limit state example, the model fitting approach and LRFD calibration methodology is applicable to a wide range of other soil-structure limit state design problems in geotechnical engineering.
    关键词:钢铁;极限状态;金属;附加载荷
  • 3098.加筋土城墙极限平衡性能和工作受压比较

    [黑色金属冶炼和压延加工业] [2014-07-26]

    The paper is focused on issues related to the behavior of reinforced soil walls at working stress and near failure, and the prediction accuracy of internal stability working stress and limit equilibrium (LE) design methods. The paper identifies the key variables, principles and assumptions that affect the accuracy of these methods considering the full range of conditions from working stress to failure. The strain at peak strength of a granular soil wall backfill is identified as a key parameter for understanding the differences between working stress and LE design methods. Both geosynthetic and steel reinforced wall systems are examined using measured reinforcement strain and loads taken from full-scale walls under both working stress (operational) conditions and at incipient collapse (failure).
    关键词:钢铁;工作压力;极限平衡;钢筋
  • 3099.12341号高放废物罐振动分析的优势

    [石油加工、炼焦和核燃料加工业,化学原料和化学制品制造业] [2014-07-26]

    Vibration analyses of equipment intended for use in the Savannah River Site (SRS) radioactive liquid waste storage tanks are performed during pre-deployment testing and has been demonstrated to be effective in reducing the life-cycle costs of the equipment. Benefits of using vibration analysis to identify rotating machinery problems prior to deployment in radioactive service will be presented in this paper. Problems encountered at SRS and actions to correct or lessen the severity of the problem are discussed. In short, multi-million dollar cost saving have been realized at SRS as a direct result of vibration analysis on existing equipment. Vibration analysis of equipment prior to installation can potentially reduce inservice failures, and increases reliability. High-level radioactive waste is currently stored in underground carbon steel waste tanks at the United States Department of Energy (DOE) Savannah River Site and at the Hanford Site, WA. Various types of rotating machinery (pumps and separations equipment) are used to manage and retrieve the tank contents. Installation, maintenance, and repair of these pumps and other equipment are expensive. In fact, costs to remove and replace a single pump can be as high as a half million dollars due to requirements for radioactive containment. Problems that lead to in-service maintenance and/or equipment replacement can quickly exceed the initial investment, increase radiological exposure, generate additional waste, and risk contamination of personnel and the work environment. Several different types of equipment are considered in this paper, but pumps provide an initial example for the use of vibration analysis.
    关键词:钢铁;高放废物;放射性废物管理;储罐;碳钢
  • 3100.大直径钢管混凝土柱单轴压缩承载力的试验研究

    [黑色金属冶炼和压延加工业] [2014-07-26]

    This paper focused on the uniaxial ultimate-bearing-capacity of large size concrete filled steel tubular (CFST) columns. Two aspects were investigated experimentally. To verify the feasibility of similarity principles for large size components, a series of uniaxial compressive experiments were conducted using different scaled specimens, the prototype of which is a CFST arch rib in an authentic arch bridge. Meanwhile, two specimens with same scale were tested axially and eccentrically to investigate the difference of bearing capacity resulted from the pierced-column. The experimental results show that the size effect on the bearing capacity of the rib is so insignificant that the scaled specimen can be used to obtain the maximum capacity of the full-scale component. The inserted steel tubes in the middle of the column cause the reduction of its capacity and the reduction factor from axial loading is bigger than that from bias load. Moreover, the eccentricity reduces the effect of piercing on the capacity of CFST column.
    关键词:钢管混凝土(CFST)柱;单轴压缩;承载力;大口径柱
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