We consider a cutting problem, which have a practical application. In this problem, items are being cut from larger items, for example textile patterns from a panel of cloth. We deal steel tubes of given length, which have to be sawed from longer steel tubes. These longer steel tubes come with given costs and the sawing has to be planned such that the total costs are minimized.

关键词：切割的问题；一维；吉尔摩和戈莫里方法；钢铁

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The Universal Breakaway Steel Post (UBSP) was developed and evaluated to replace the existing Controlled Release Terminal (CRT) wood posts which were used in the original bullnose guardrail system. Previously, three full-scale crash tests were performed on the thrie beam bullnose barrier with UBSPs, and the UBSP was determined to be a suitable alternative for the CRT posts. However, the UBSP was modified prior to the completion of the full-scale tests, and dynamic component testing was not conducted to compare the post behaviors. Therefore, a series of nine component tests were conducted in soil to compare the weak- and strong-axis properties between the UBSPs and CRT posts. As part of the component testing, one of the weak-axis tests involving the UBSP was conducted with a reused lower section of the post; since, the original development of the UBSP recommended reuse as long as the lower section was undamaged and displaced less than 12 in. (13 mm). From the testing series, it was determined that the performance of the UBSP indicated a strong potential for these posts to be utilized in other applications. However, UBSP should first be evaluated through engineering analysis and full-scale crash testing before implementation.

关键词：碰撞测试；动态测试；护栏岗位；钢铁

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To develop an effective software for finite element (FE) model updating of bridges, the interface technology between VC++ and MATLAB was investigated firstly, and then a software for updating FE model of bridges, named 'Doctor for Bridges' (version 1.0) was developed. Finally, a model ofconcrete-filled steel tube arch bridge was applied to verify the performance and effectiveness of the proposed software.

关键词：桥梁；有限元模型修正；接口技术

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Driven piles are subjected to high stresses during installation. It is, therefore, important not to exceed acceptable stresses along the pile shaft and at the toe to prevent damage. Dynamic monitoring has been used for decades to evaluate not only the installation stresses, but also check test piles for signs of structural damage. The Beta Method (?-Method) for evaluation of the location and extent of a potential damage was developed over thirty years ago and has proven effective as a QC and QA tool. As an aid in the process of pile rejection or acceptance, the ?-Method also offers a rating scale which translates the automatically determined ?-number into a helpful pile integrity assessment tool. The reliability of this algorithm has been proven by numerous extracted piles. However, one limitation of the ?-method concerned detection of damage near the pile toe where high toe resistance effects and/or stress wave reflections reduce the effectiveness of the traditional ?-Method. In the past, therefore, near-toe damage was determined by the testing engineer, not only by visual inspection of the dynamic monitoring data, but also by reviewing the pile toe compressive stresses throughout the monitored driving history and the strength and stiffness of the soil response from the pile toe. This approach has now been automated and subjected to tests on existing data. After a review of the existing methods of pile stress and damage calculations, the paper presents the new method, illustrating its effectiveness by examples from measurements on both concrete and steel piles.

关键词：打入桩；钢铁；动态监测

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A data base of 84 pile load tests was developed for steel pipe piles, driven in clay (small amounts of sand near the surface for a few tests), where there was sufficient data to estimate effective overburden pressures with reasonable accuracy, where soil strengths were well defined, and where a load-settlement curve was available for the load test. Measured pile capacities were compared with values predicted using five methods that have been, are being, or potentially may be used in engineering practice. The two lambda methods had the least scatter but tended to overpredict capacities by about 20%. The current API method had slightly more scatter but overpredicted capacities by only about 13% on the average. The two alpha methods had the largest scatter and the greatest differences between measured and predicted capacities.

关键词：荷载试验；钢铁；负载沉降曲线

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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：钢管挤压；钢铁；荷载位移数据

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In August 2010, Midwest Roadside Safety Facility (MwRSF) developed and crash tested a low-cost, energy-absorbing bridge rail for the Manual for Assessing Safety Hardware (MASH) TL-3 applications. This low-cost bridge rail was designed to be compatible with the Midwest Guardrail System (MGS) such that an approach transition would not be required between the two barriers. It was desired that the system minimize bridge deck and rail costs. As part of this project, several concepts for an energy-absorbing bridge post were developed and tested. These concepts included strong-post systems designed with plastic hinges and weak-post systems designed to bend near the attachment to the bridge deck. The final post concept incorporated S3 OE 5.7 steel sections designed to yield at their bases. These posts were located on 6 ft-3 inches on center. A W-beam section was used as the rail element and was attached to the posts with a bolt designed to break during and impact event. Two full-scale crash tests were performed according to the TL-2 impact conditions provided in MASH. The new bridge rail system successfully met all the safety performance criteria for MASH TL-2. The Texas Type T631 Bridge Rail was developed as a low-cost, energy absorbing bridge rail system for TL-2 applications. Many of the features used for the system tested at Midwest Roadside Safety Facility for TL-3 were incorporated into the design developed for this project for MASH TL-2 application. The TxDOT Type T631 Bridge Rail designed and developed for this project was evaluated under MASH TL-2.

关键词：大桥护栏；碰撞测试；钢铁

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Based on node test and finite element analysis results of four different structural form enhanced nodes,failure modes,hysteretic behavior,bearing capacity,ductility and energy dissipation capacity of nodes are analyzed comprehensively and comparatively for more in-depth exploration about the seismic performance of symmetric enhanced nodes.The results showed that all the symmetric enhanced nodes have full hysteretic curve and energy dissipation capacity.On the whole,The flange-plate reinforced node exhibit better seismic performance.

关键词：钢框架；加强节点；循环加载试验；有限元分析

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Using a 1984 benchmark experiment, MCNP6 replicated the neutron flux and neutron protection factor (NPF) measurements of an iron box, which simulated a basic military vehicle, resulting in less than 5% difference from the published results. Additionally, the neutron flux spectrum of a 239 PuBe source was characterized using a Bonner Sphere Spectrometer (BSS) and the solution unfolded using the Maximum Entropy Deconvolution (MAXED) program, producing a X2/df of 0.97. Utilizing a steel box provided by the DTRA, measurements of neutron flux from a D-D neutron accelerator were recorded via BSS inside and outside of the box. Both flux spectra were unfolded through MAXED using MCNP6 computations as a priori, which resulted in X2/df values of 0.86 and 0.91, respectively. NPF assessments of the steel box were then conducted using experimental and MCNP6 flux spectra for the box, as well as H*(10) scaling, with final results differing by less than 1%. MAXED software was leveraged for all flux spectrum unfolding, incorporating updated BSS response functions generated within this research from MCNP6. This experiment and its conclusions strongly support the verification and validation of MCNP6 for modeling NPF assessments of military vehicles.

关键词：中子通量；中子保护因子；中子能谱；钢铁

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This paper presented the results of testing reinforced concrete beams strengthening with the BFRP sheets. Five specimens were cast and tested. All specimens were 2600 mm total span with a cross section of 150mm width and 250mm depth. Out of the specimens, two specimens were designed as reference specimens. The rest specimens were repaired with the BFRP sheets. The variables examine in the experiment were the longitudinal tensile reinforcement ratio, the different layers of the BFRP sheets and the anchoring measures of BFRP sheets. All specimens were tested under simply supported condition. 3D nonlinear finite element (FE) numerical models by ANSYS10.0 software were conducted to accurately predict the ultimate bearing capacity and response of reinforced concrete specimens strengthening with BFRP sheets subjected to four-point bending loading. The nonlinear constitutive material properties of concrete and steel reinforcement were considered in the finite element model. The results of the FEM simulation were compared with that of the experimental specimens. The results showed that it was significantly effective for the flexural capacity of the BFRP sheet-bonded reinforcement in tensile zone for reinforced concrete beams. Moreover, it implied excellent results on the stiffness of the reinforced concrete beams. The flexural strength enhancement of the reinforced concrete beams strengthening with the BFRP sheets varied between 19% ~ 44% over the control beam. This study further identified that the BFRP sheet technique significantly enhanced the stiffness and flexural capacity of reinforced concrete beams.

关键词：增强复合材料（BFRP）；钢筋混凝土梁（RC）；承载力

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