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1.
Analysis of structural response under blast loads using the coupled SPH-FEM approach 总被引：3，自引：0，他引：3
A numerical model using the coupled smoothed panicle hydrodynamics-finite element method （SPH-FEM） approach is presented for analysis of structures under blast loads. The analyses on two numerical cases, one for free field explosive and the other for structural response under blast loads, are performed to model the whole processes from the propagation of the pressure wave to the response of structures. Based on the simulation, it is concluded that this model can be used for reasonably accurate explosive analysis of structures. The resulting information would be valuable for protecting structures under blast loads. 相似文献
2.
桥梁结构有限元分析软件MIDAS在桥梁结构分析中的应用日益广泛。随着社会的快速发展,车辆荷载变异严重,立交桥不时承担着重车超重等荷载作用。经检测发现某地一立交桥有多联梁体偏移严重,且梁体存在受力裂缝及其他裂纹等病害。为摸清该桥的受力性能,基于通用计算机软件MIDAS对该立交桥梁进行加固处理并进行静动载结构分析,分析结果为该桥的使用性能及其加固提供了参考。 相似文献
3.
莫文辉 《十堰职业技术学院学报》2010,23(3):107-109
考虑材料空间多样性,材料性能特性例如弹性模量或波松比被看成随机过程。本文采用随机场的中心点方法,在材料性能特性、几何尺寸、所受载荷被看成随机的情况下,结构振动方程先用Newmark法转化为静力问题。二阶Taylor展开随机有限元被用于结构振动分析,推导简单,易于编程。给出了基于随机有限元的混凝土悬臂梁的振动分析的一个计算实例,对计算结果做了比较,本文提出的方法是有效的。 相似文献
4.
The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables'sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper. 相似文献
5.
The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables' sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper. 相似文献
6.
For the dynamic demand assessment of bridge structures under ship impact loading, it may be prudent to adopt analytical models
which permit rapid analysis with reasonable accuracy. Herein, a nonlinear dynamic macro-element is proposed and implemented
to quantify the demand of bridge substructures subjected to ship collisions. In the proposed nonlinear macro-element, a combination
of an elastic-plastic spring and a dashpot in parallel is employed to describe the mechanical behavior of ship-bows with strain
rate effects. Based on the analytical model using the proposed macro-element, a typical substructure under 5000 deadweight
tonnage (DWT) ship collision is discussed. Our analyses indicate that the responses of the structure using the nonlinear macro-element
agree with the results from the high resolution model, but the efficiency and feasibility of the proposed method increase
significantly in practical applications. Furthermore, comparisons between some current design codes (AASHTO, JTGD60-2004,
and TB10002.1-2005) and the developed dynamic analysis method suggest that these design codes may be improved, at least to
consider the effect of dynamic amplification on structural demand. 相似文献
7.
随着中国经济的发展,兴建了大量的体育馆、飞机库、展厅等空间结构,空间结构已经成为现代生活的重要组成部分 简要介绍空间结构在中国发展的原因,以及在网壳结构、悬索结构、膜结构等方面发展的状况及发展前景 相似文献
8.
区域经济空间结构重组与产业结构调整关系研究 总被引：1，自引：0，他引：1
伍贤旭 《齐齐哈尔师范高等专科学校学报》2004,23(2):8-10
空间结构和产业结构作为区域经济结构最重要的两个方面，二者之间存在非常密切的联系．本文认为：城市化是联系经济空间结构重组与产业结构调整的纽带：产业结构影响着经济空间相互作用的产生；产业结构与经济空间结构存在着阶段性的对应关系．我们应从产业结构调整与经济空同结构重组相统一的角度去调整区域经济结构。 相似文献
9.
教育工程项目是一类结构化的实体。包含目标、任务、组织、成本等四大基本元素,四者构成了一个需要保持平衡的结构系统。结构有时间结构和空间结构之分,每类元素都有各自独特的时间结构和空闻结构。详细分析教育工程项目基本元素的时空结构。可以为教育工程项目的设计和实施提供清晰的结构视图。 相似文献
10.
The asymptotically distribution free (ADF) method is often used to estimate parameters or test models without a normal distribution assumption on variables, both in covariance structure analysis and in correlation structure analysis. However, little has been done to study the differences in behaviors of the ADF method in covariance versus correlation structure analysis. The behaviors of 3 test statistics frequently used to evaluate structural equation models with nonnormally distributed variables, χ2 test TAGLS and its small-sample variants TYB and TF(AGLS) were compared. Results showed that the ADF method in correlation structure analysis with test statistic TAGLS performs much better at small sample sizes than the corresponding test for covariance structures. In contrast, test statistics TYB and TF(AGLS) under the same conditions generally perform better with covariance structures than with correlation structures. It is proposed that excessively large and variable condition numbers of weight matrices are a cause of poor behavior of ADF test statistics in small samples, and results showed that these condition numbers are systematically increased with substantial increase in variance as sample size decreases. Implications for research and practice are discussed. 相似文献
11.
区域产业结构优化的研究的核心内容是建立在评价、分析资源合理配置基础上的区域分析。本文从丹东市区域条件分析入手，系统分析了丹东市产业部门结构及空间结构调整的优势条件和劣势条件，最后指出了丹东市产业结构优化和开发重点。 相似文献
12.
崔竹朝 《石家庄职业技术学院学报》2005,17(3):53-55
在由实词与实词组成的句法结构中，总是同时并存着两种结构关系：语法结构关系和语义结构关系。这是两种性质完全不同的结构，二者之间存在着错综复杂的关系，主要表现在：同一种语法结构可以表达多种语义结构；多种语法结构可以表达一种语义结构；同一种语法成分，可以有不同的语义指向；同一个句子，可以表现出不同的语法结构和语义结构。 相似文献
13.
通过对浙闽木拱廊桥的结构组成体系及几何构造的定性分析,指出相关文献把木拱廊桥桥拱结构描述为稳定高次超静定体系是不恰当的。用实例说明其结构体系存在几何瞬变和几何可变的可能,并讨论具有互承结构性能的编织结构体系的机动性。 相似文献
14.
钢梁与钢筋混凝土桥墩的新型刚节点联结形式及其静载反复试验 总被引：1，自引：0，他引：1
提出了一种新型的桥梁钢梁与钢筋混凝土桥墩的刚节点联结形式．刚节点内部构件间的连接全部采用高强度螺栓连接方式且施工方便，能够较理想地将上部结构弯矩传递到下部结构，剪力传递钢板承受了大部分的水平剪力．通过静荷载反复试验获得了有关这种新型结构性能方面的有效数据，试验结果表明该结构内部应力传递路径明确，并具有良好的抗震性能．有关结构的强度和塑性变形的计算及试验结果均表明，这种结构即使在发生很大变形的情况下，也能保持良好的能量吸收功能且没有出现因应力集中而发生的局部曲屈现象．由于避免使用了价格昂贵的支座，采用这种新型组合结构形式不但具有良好的抗震性能，同时可以降低桥梁的建设成本． 相似文献
15.
16.
复杂体型钢筋混凝土高层建筑的推覆分析方法和应用 总被引：2，自引：0，他引：2
In this paper, push-over analysis for tall concrete structures was made and a corresponding computer program was given.Several kinds of elements in the program were considered to meet the demand of tall buildings with complex structural type. These elements included beam-column element for beams and columns, single slice wall element and three vertical line element for walls, and tube-wall element for tubes. Computational example for verifying the models indicates that the result obtained by this method is identical with a well-known test result and the program can be used to search for the full process of structural reaction, even the softening stage of the structure. With this push-over analysis method, an actual tall building with complex structural type was analyzed, and the result has been put into practice of the structural design of the building. 相似文献
17.
应用Pro/E对平板式半挂车车架进行三维实体建模。对该模型进行简化处理、抽中面和修补后导入ANSYS。采用壳单元建立平板式半挂车车架的有限元模型,对车架进行静力分析和模态分析。结果表明,车架在弯曲和扭转工况下,刚度和强度满足要求;车架结构的低阶模态频率不在路面激励频带之内,不会产生共振现象。 相似文献
18.
语法构式与修辞构式共处于同一个连续统中,之间不可能有一个分明的界线,重“通”或重“工”的语用功能是分别构式性质的前提。修辞构式必有语法构式的依托,语法构式衍变为修辞构式基于构式词变、义变、式变等多种因素的相互作用,是构式意义压制的必然后果。修辞构式向新的语法构式的转化是语法类推机制作用的结果,修辞构式有限的能产性磨蚀了构式不可推导性的根基,也成为衍生新的非典型语法构式的基础。 相似文献
19.
邢楠 《河北能源职业技术学院学报》2008,8(4):42-43
2008年新的《企业所得税法》中的生态性条款,经历了动态的历史发展,正在形成其自身的静态结构,并很可能将要有更广泛和更深化的进步。本文从动静态两个角度评析生态性条款,论证其对经济环境可持续发展的现实作用,探讨其目前仍然存在的不足之处,提出进一步完善的建议。 相似文献
20.
《天津大学学报(英文版)》2015,(4)
Free-interface dual-compatibility modal synthesis method(compatibility of both force and displacement on interfaces)is introduced to large-scale civil engineering structure to enhance computation efficiency. The basic equations of the method are first set up, and then the mode cut-off principle and the dividing principle are proposed. MATLAB is used for simulation in different frame structures. The simulation results demonstrate the applicability of this substructure method to civil engineering structures and the correctness of the proposed mode cut-off principle. Studies are also conducted on how to divide the whole structure for better computation efficiency while maintaining better precision. It is observed that the geometry and material properties should be considered, and the synthesis results would be more precise when the inflection points of the mode shapes are taken into consideration. Furthermore, the simulation performed on a large-scale high-rise connected structure further proves the feasibility and efficiency of this modal synthesis method compared with the traditional global method. It is also concluded from the simulation results that the fewer number of DOFs in each substructure will result in better computation efficiency, but too many substructures will be time-consuming due to the tedious synthesis procedures. Moreover, the substructures with free interface will introduce errors and reduce the precision dramatically, which should be avoided. 相似文献