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31.
根据拉格朗日方程推导了结构设置FPS调谐质量系统地震动力反应分析计算公式,并考虑了接触面滞滑效应的影响。分析与计算结果表明:设置质量调谐系统之后,结构动力反应层间位移有所减小。当接触面滑动摩擦系数为0.15左右、滑道半径为0.7 m、调谐附加质量为楼层质量的1.4倍以上时,质量调谐系统具有较好的减振效果、消能效果与复位能力。 相似文献
32.
This paper describes the framework and application of numerical simulation software on earthquake engineering research and practice. The analysis kernel is developed at the National Center for Research on Earthquake Engineering (NCREE) and is entitled as “Platform of Inelastic Structural Analysis for 3D systems (PISA3D)”. The design of PISA3D framework adopts the Design Pattern and the Unified Process. PISA3D provides structural modeling and high computational efficiency for engineers and researchers to simulate the responses of nonlinear systems under various kinds of load effects. It includes static or cyclic loads, displacements, earthquake ground accelerations, and earthquake aftershocks. PISA3D is easy to extend and maintain due to its object-oriented nature. Advanced users can derive or compose its objects’ libraries to perform different types of structural analyses. Based on object-oriented techniques, VISA3D (Visualization of Inelastic Structural Analysis for 3D systems) has been implemented with usage of OpenGL for 3D graphics and MFC for graphical user interface (GUI). Its framework allows further extension on new input formats and new element types. VISA3D has been mainly developed as a post-processor to examine the analytical results of PISA3D through 2D/3D static or dynamic graphic approaches. It includes graphical checking of the structural model, mode shapes, deformations, extents and locations of plastic hinges, plotting of nodal velocity, acceleration, and energy distribution time histories. This paper then introduces NCREE’s recent development on the pre-processing framework GISA3D (Graphical Interface of Inelastic Structural Analysis for 3D systems). The GISA3D does not only supply features as a “post-processor”, but also fully supports operations of “model generation” via mouse motion. Users can create, remove, modify and set elements/nodes through mouse clicking, dragging and selecting. Finally, this paper illustrates the networked sub-structural pseudo dynamic tests using PISA3D as the analysis engine, and concludes with several successful applications of PISA3D/VISA3D/GISA3D on various researches and actual structural engineering projects. 相似文献
33.
《Composites Part B》2013,44(8):3061-3068
Due to its superior damping ratio, high adhesion and fast curing, polymer concrete is used in manufacturing bases for a wide range of precision machines. The coefficient of thermal expansion for polymer concrete is one of the main parameters that can affect the level of accuracy in precision tool machines. Flexural strength is a fundamental strength of the base. In this study six aggregates (basalt, spodumene, fly ash, river gravel, sand and chalk) were investigated. Polymer concrete samples were prepared with different compositions of aggregates containing the same resin volume fraction (aggregates 83% and risen 17%). A four points flexural test was employed to measure the flexural strength of the polymer concrete samples. The coefficient of thermal expansion for polymer concrete was measured using a custom built device. The preliminary optimum composition, with the highest flexural strength and lowest thermal expansion coefficient, was found to be basalt, spodumene and fly ash. Basalt, sand and fly ash composition was the second in the rank. The second composition was nominated for further optimization in terms of resin volume fraction in consideration of its ability to adapt a smaller amount of resin. Different samples of polymer concrete were prepared with a variety of resin volume fractions as follows; 17%, 15% and 13%. The resin volume fraction has been demonstrated to have a significant effect on the coefficient of thermal expansion and flexural strength for polymer concrete. The final optimized composition was basalt, sand and fly ash (filler 87% and resin 13%). ANSYS 13 software was employed in visualizing the influence of polymer concrete compositions on the thermal expansion of the base and how it affected the level of precision of the tool machine. 相似文献
34.
对在P波、SV波和SH波入射下的局部不规则场地,如圆弧形凹陷地形、圆弧形沉积谷场地,地下衬砌隧道和地下双洞室造成的散射以及由此产生的放大及其他危害作用做了大致的概括。 相似文献
35.
36.
江西九江-瑞昌M5.7级地震空斗砖墙房屋震害分析 总被引:3,自引:1,他引:2
本文通过对2005年11月26日江西九江—瑞昌5.7级地震建筑震害的现场调查,介绍了当地村镇中普遍采用的空斗砖墙房屋的破坏情况,并对典型实例进行剖析,总结经验教训。提出的改进意见可供该地区的灾后重建和正在编制的《村庄与集镇建筑抗震技术规程》参考。 相似文献
37.
LRB隔震结构模型振动台试验研究(2) 总被引:2,自引:1,他引:1
为研究大高宽比隔震结构的多维抗震性能,对一缩尺1∶4比例,两向高宽比分别为2.5和5的铅芯橡胶垫隔震结构模型进行了多向地震波输入下的振动台试验研究.试验分为小高宽比隔震结构模型双向地震波输入、大高宽比隔震结构模型三向地震波输入.通过输入不同大小和类型的地震波,分析隔震上部结构和隔震支座的地震反应.试验结果表明:各向地震波对结构反应将产生复杂的相互影响,当各向地震波发生峰值时刻接近时,这种影响更为显著.因此从安全考虑应该进行水平双向组合变形验算. 相似文献
38.
《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1987,256(3):587-594
Longitudinal emission computed tomography (LECT), is shown to generate images with a reconstruction error independent of both the reconstruction algorithm and the physical performance of the viewing system. In general, activity will be predicted to extend into space beyond the true object boundary and the predicted, relative distribution of activity will be incorrect. A method is described which identifies the direction involving the maximum reconstruction error and gives a measure of the maximum error volume; its application in the optimisation of some common LECT systems is demonstrated. 相似文献
39.
40.
斜拉桥锚拉板式索梁锚固区试验模型优化研究 总被引:1,自引:0,他引:1
国内外常采用理论分析和模型试验相结合的方式来研究斜拉桥索梁锚固结构的应力特征。以某斜拉桥锚拉板式索梁锚固结构为例,采用桥梁专业计算软件MIDAS CIVIL建立全桥空间杆系模型,确定了索梁锚固区试验模型的选取位置,采用大型通用有限元软件ABAQUS建立选取节段空间板单元模型,经过对比分析,对锚拉板式索梁锚固区试验模型进行了长度、宽度和高度的优化。最终确定的索梁锚固区试验模型不仅满足了实验室场地要求、设备要求和材料的合理利用,还保持了与原桥的高度相似性,保证了后续试验的可行性。 相似文献