共查询到19条相似文献，搜索用时 875 毫秒
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目前在工程中，临时支撑卸载过程的分析和模拟主要有两种方法．利用这两种方法分别建立临时支撑卸载的有限元模型并在ANSYS中对这两个模型的卸载过程进行模拟和分析，从理论上和有限元分析结果上对这两种方法进行了探讨． 相似文献
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对山西省万家寨引黄入晋工程总干线7号隧洞开挖和蓄水运行的几种工况进行了非线性有限元分析．主要内容包括采用分级堆填过程模拟风积黄土层的初始应力场；应用：Duncan释放荷载思想和弹性理论面力公式进行开挖卸荷计算；采用Goodman节理单元模拟衬砌管片的接缝；应用Terzaghi松动土压力理论施加管片上压力；确定土的Duncan-Chang模型参数时，分别取原状土进行了卸载和加载试验，并比较了用2种试验获得的模型参数进行有限元变形分析的结果，多种工况的有限元分析得到了一些合理的结果． 相似文献
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超长钻孔灌注群桩承载特性的实验研究和数值分析 总被引：1，自引：0，他引：1
采用离心机模型试验和三维有限元模型对天兴洲大桥的超长嵌岩钻孔灌注群桩进行了分析.离心机试验中,根据相似理论,不同的原型材料用不同的指标进行模拟,细砂、桩身、承台分别以天然密度、抗压刚度、抗弯刚度作为指标进行模拟.对土体未开挖阶段、钻孔阶段、混凝土灌注阶段和养护阶段的应力场进行了详细的讨论,并应用ANSYS进行了分析.根据2种方法得到的结果,从荷载沉降曲线、桩身轴力分布和侧向摩阻分布等方面,对比分析了加载和卸载条件下超长钻孔群桩的承载特性.结果表明,有限元计算模型与离心机试验模型沉降观测的结果吻合得很好;桩顶反力的分布规律复杂,与承台的自身刚度、相应的假定和分析方法有关;轴力随着深度先稍微增加,后逐渐减少,并且在岩层中减少的速度远比砂土中快. 相似文献
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《石家庄铁路职业技术学院学报》2015,(1)
以跨津秦客专跨径80.6+128+80.6m的连续梁临时支墩设计为例,对连续梁临时支墩的计算过程进行了详细的阐述,并通过有限元软件Midas对京津城际延伸线跨津秦客专特大桥的临时支墩进行了数值分析,结合施工现场的实际情况,说明有限元数值模拟方法满足施工现场要求。 相似文献
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采用有限元软件MSC．Superform对角钢热连轧过程进行有限元模拟。介绍了模拟过程中的模型建立、材料参数、边界条件以及载荷的定义,分析了轧制过程中轧件温度场的分布和变化过程,分析结果对制定角钢热连轧过程的温度制度提供了有效参考。 相似文献
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本文运用计算机仿真软件包SHEET-FORMING对复杂薄板零件波纹成形过程进行数值模拟。本文认为,运用高压橡皮成形工艺成形波纹板零件是可行的,预示了加载成形中毛坯变形过程和卸载回弹中成形件的回弹状态,为有限元数值模拟技术在高压橡皮成形工艺中的应用积累了有用数据。本文所做的研究对实际生产具有指导作用。 相似文献
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李云霞 《昆明师范高等专科学校学报》2009,31(6):92-93,96
根据薄板轧制中出现的大变形、大位移兼有弹性变形的特点,选用弹塑性有限元法对该过程进行分析,建立薄板冷轧的有限元模型,并在LS—DYNA软件平台上进行有限元分析求解,对轧制全过程进行模拟仿真,得到轧制过程的应力、应变模型．由轧制过程的模拟仿真结果分析,可获得最优的轧制条件,从而更精确的进行质量控制． 相似文献
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利用大型有限元软件ANSYS/LS-DYNA的模拟功能,对轧辊的裂纹尖端开裂模式进行了模拟分析。在将裂纹尖端区域细化的基础上,得出含表面裂纹的热轧工作辊两个裂纹尖端的开裂模式是不同的,并且随着轧制深入以及裂纹扩展规律的影响,出现了裂纹尖端局部塑性区以及材料局部的卸载情况,使应力强度因子K以及J积分之间不再满足在线弹性过程中的换算关系形式。 相似文献
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With the development of computer simulation technique for room acoustics, diffuse reflection is considered more and more important.
In this paper, some models are developed by considering two diffuse factors in a room-diffuse reflection due to room surfaces
and scattering due to objects. The surface diffusion is treated by two different methods on the basis of probability analysis
or Energy Conservation Law, and the scattering among objects is simulated as a multiple random ray-tracing process. Thus the
sound pressure level distribution in a diffuse sound field can be calculated more precisely and easily. Agreement between
the computer simulation results and measurements shows the accuracy of the mathematical and physical model and the applicability
of the computer simulation methods. These models can be used in noise control engineering, as well as in the practice of acoustical
design. 相似文献
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ＩＮＴＲＯＤＵＣＴＩＯＮＷｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｃｏｍｐｕｔｅｒｓｉｍｕｌａｔｉｏｎｔｅｃｈｎｉｑｕｅｆｏｒｒｏｏｍａｃｏｕｓｔｉｃｓ,ｎｅｗｍｏｄｅｌｓｈａｖｅｂｅｅｎｐｒｏｐｏｓｅｄｆｏｒｍｏｒｅｐｒｅｃｉｓｅｌｙｓｉｍｕｌａｔｉｎｇｓｏｕｎｄｆｉｅｌｄｓｔｏｒｅａｌｉｚｅａｕｒａｌｉｚａｔｉｏｎ .Ｔｈｅｃｏｍｐｕｔ ｅｒｈａｓｐｌａｙｅｄａｖｅｒｙｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｔｈｅｒｅ ｓｅａｒｃｈｏｎｓｏｕｎｄｐｒｏｐａｇａｔｉｏｎ ,ｉｎｔｈｅｐｒｅｄｉｃｔｉｏｎｏｆｒｏ… 相似文献
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Karen Nylund-Gibson Ryan P. Grimm Katherine E. Masyn 《Structural equation modeling》2013,20(6):967-985
Including auxiliary variables such as antecedent and consequent variables in mixture models provides valuable insight in understanding the population heterogeneity embodied by a latent class variable. The model building process regarding how to include predictors/correlates and outcomes of the latent class variables into mixture models is an area of active research. As such, new methods of including these variables continue to emerge and best practices for the application of these methods in real data settings (including simple guidelines for choosing amongst them) are still not well established. This paper focuses on one type of auxiliary variable—distal outcomes—providing an overview of the methods currently available for estimating the effects of latent class membership on subsequent distal outcomes. We illustrate the recommended methods in the software packages Mplus and Latent Gold using a latent class model to capture population heterogeneity in students’ mathematics attitudes, linking latent class membership to two distal outcomes. 相似文献
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p-q和ip-iq两种谐波检测方法的仿真对比 总被引：2，自引：0，他引：2
针对基于瞬时无功功率理论的p-q和ip-iq两种谐波检测方法建立了仿真模型,并在电网电压有无畸变时进行了仿真和对比。结果表明,ip-iq法在电网电压有无畸变时均能从负载电流中准确地将谐波检测出来,而p-q法只在电网电压无畸变时,才能将负载电流中的基波分量和谐波分量有效地分离开。本研究为在谐波抑制中合理选取谐波检测方法提供了理论依据。 相似文献
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New technology enables interactive and adaptive scenario‐based tasks (SBTs) to be adopted in educational measurement. At the same time, it is a challenging problem to build appropriate psychometric models to analyze data collected from these tasks, due to the complexity of the data. This study focuses on process data collected from SBTs. We explore the potential of using concepts and methods from social network analysis to represent and analyze process data. Empirical data were collected from the assessment of Technology and Engineering Literacy, conducted as part of the National Assessment of Educational Progress. For the activity sequences in the process data, we created a transition network using weighted directed networks, with nodes representing actions and directed links connecting two actions only if the first action is followed by the second action in the sequence. This study shows how visualization of the transition networks represents process data and provides insights for item design. This study also explores how network measures are related to existing scoring rubrics and how detailed network measures can be used to make intergroup comparisons. 相似文献
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詹瑾 《广东技术师范学院学报》2007,(7):6-8
目前常用的软件过程模型有CMM、PSP、TSP和敏捷开发过程等,对这些过程模型的使用,需采用统计过程控制方法的控制图等工具对过程数据采样点进行分析,以便了解过程性能和过程能力,采取措施消除过程异常,保证过程的稳定性,从而提高软件开发质量.本文简要介绍了CMM、PSP等过程模型以及基于离散数据的控制图分析过程稳定性的方法. 相似文献
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《Performance Improvement》2017,56(8):37-45
Not all instructional design models are fully integrated into the HPT practice. Some of these processes such as the successive approximation model (SAM) and the lot like Agile methods approach (LLAMA) are the outgrowth of Agile processes for instructional design. The major design processes are often assumed to be competitive; that is, one model is better than the other. However, most Agile instructional design processes assume that the most ubiquitous performance solution is e‐learning, hence the direct integration of Agile processes. Therefore, instead of thinking about design models, we think about instructional methods and solutions over human performance technology (HPT). These methods are all equal until one understands the conditions or the context of the instructional or performance problem. We recommend designers reverse engineer the Agile instructional systems design process by using a rapid performance analysis method that quickly pinpoints and confirms the performance problem(s). 相似文献