剪式液压升降台相关参数的确定

设计剪式液压升降台要解决的关键问题,是科学、合理地确定液压缸的有效行程及其它结构参数.液压缸的有效行程受各结构参数的影响,而这些参数又影响液压缸的受力,各参数之间的关系错综复杂.要设计出液压缸受力小,而又能满足运动要求的剪式液压升降台,必须明确各参数之间的相互关系,进行综合分析.通过分析剪式液压升降台的运动过程,推导出了满足升降台升降的相关参数的关系式;通过分析和比较升降台在负重上升过程中液压缸推力的变化规律,确定了铰架仰角a的取值范围、液压缸的有效行程及有关结构参数的取值规律,为升降台的系列设计提供了理论依据.     

基于BIM技术的施工工艺管理平台研究及应用

近年来,动态施工工艺展示技术在工程实践中发挥了日益重要的辅助建造作用。针对动态施工工艺创建技术门槛较高、集成管理难度大、复用程度低的技术现状。本文从多源数据参数共享的角度,实现了动态施工工艺的快速、精准创建。同时,结合软件工程学的方法,研发了基于BIM技术的施工工艺管理平台,实现了动态施工工艺的企业级的集中创建和集成管理,有效地助力了现场管理。工程实践显示：基于BIM技术的施工工艺管理平台能够实现施工工艺的集成管理和广泛复用,具有极好的应用前景。     

采用静态和动态法改进有限元模型进行桥梁评估

通过有限元模型升级,将有限元分析与现场测量相结合,其潜力毋庸置疑。然而,简单化的初始模型和缺少测量可能导致升级的模型参数隐藏了不准确的模型假设,而不是提高实际结构参数的评估。因此,所提出方法的目标主要是在采用非线性优化对参数进行评估之前,借助手工模型的精度消除不精确的模型简化。此外,引进多级响应目标函数,结合不同类型的测量获得参数评估的坚实基础。所提方法被用于世界上最大的Svinesund单孔桥,研究表明采用非线性模型可对模型参数进行精确评估。     

Dynamic experiments with high bisphenol-A concentrations modelled with an ASM model extended to include a separate XOC degrading microorganism

The perspective of this work is to develop a model, which can be used to better understand and optimize wastewater treatment plants that are able to remove xenobiotic organic compounds (XOCs) in combination with removal of traditional pollutants. Results from dynamic experiments conducted with the endocrine disrupting XOC bisphenol-A (BPA) in an activated sludge process with real wastewater were used to hypothesize an ASM-based process model including aerobic growth of a specific BPA-degrading microorganism and sorption of BPA to sludge. A parameter estimation method was developed, which simultaneously utilizes steady-state background concentrations and dynamic step response data, as well as conceptual simplifications of the plant configuration. Validation results show that biodegradation of BPA is sensitive to operational conditions before and during the experiment and that the proposed model structure is capable of capturing important characteristics of the observed BPA removal, thus increasing the potential for generalizing knowledge obtained from plant specific experiments.     

Comparison of different uncertainty techniques in urban stormwater quantity and quality modelling

Urban drainage models are important tools used by both practitioners and scientists in the field of stormwater management. These models are often conceptual and usually require calibration using local datasets. The quantification of the uncertainty associated with the models is a must, although it is rarely practiced. The International Working Group on Data and Models, which works under the IWA/IAHR Joint Committee on Urban Drainage, has been working on the development of a framework for defining and assessing uncertainties in the field of urban drainage modelling. A part of that work is the assessment and comparison of different techniques generally used in the uncertainty assessment of the parameters of water models. This paper compares a number of these techniques: the Generalized Likelihood Uncertainty Estimation (GLUE), the Shuffled Complex Evolution Metropolis algorithm (SCEM-UA), an approach based on a multi-objective auto-calibration (a multialgorithm, genetically adaptive multi-objective method, AMALGAM) and a Bayesian approach based on a simplified Markov Chain Monte Carlo method (implemented in the software MICA). To allow a meaningful comparison among the different uncertainty techniques, common criteria have been set for the likelihood formulation, defining the number of simulations, and the measure of uncertainty bounds. Moreover, all the uncertainty techniques were implemented for the same case study, in which the same stormwater quantity and quality model was used alongside the same dataset. The comparison results for a well-posed rainfall/runoff model showed that the four methods provide similar probability distributions of model parameters, and model prediction intervals. For ill-posed water quality model the differences between the results were much wider; and the paper provides the specific advantages and disadvantages of each method. In relation to computational efficiency (i.e. number of iterations required to generate the probability distribution of parameters), it was found that SCEM-UA and AMALGAM produce results quicker than GLUE in terms of required number of simulations. However, GLUE requires the lowest modelling skills and is easy to implement. All non-Bayesian methods have problems with the way they accept behavioural parameter sets, e.g. GLUE, SCEM-UA and AMALGAM have subjective acceptance thresholds, while MICA has usually problem with its hypothesis on normality of residuals. It is concluded that modellers should select the method which is most suitable for the system they are modelling (e.g. complexity of the model’s structure including the number of parameters), their skill/knowledge level, the available information, and the purpose of their study.     

耐碱玻璃纤维编织网混凝土梁抗弯性能研究

提出了采用耐碱GFRP编织网替代传统钢筋在混凝土梁中作为受力骨架的新型结构形式。为研究该类型结构的力学性能,设计了3根试件,对其进行三分点加载,观察其受力全过程及破坏特征,分析其破坏模式。在试验研究的基础上,采用ABAQUS有限元软件进行了混凝土强度参数对其力学性能影响的参数分析。试验及数值模拟结果表明:配筋率对耐碱GFRP混凝土梁的受弯性能影响较大;随着混凝土强度的提升,梁的承载力虽有所提升,但挠度降低。     

OVM - BM·A 型扁锚垫板的计算机分析与优化设计

本文利用计算机有限元分析及疲劳分析软件对OVM锚固体系的关键承载元件一锚具进行数值分析和疲劳分析,以说明OVM锚固体系的可靠性。     

细长结构单片的施工场地倒运工艺及临时支撑设计

本工艺可以实现细长结构单片的施工场地倒运及临时支撑作业。本工艺不同于传统的运输工艺,能够使场地倒运和支撑合为一个整体,简便了操作过程,提高了出片效率;能够避免了额外的焊接工作,减小或者防止对母材的破坏;使平板车的退出方向可控,可以最大限度的利用场地空间资源;能够方便单片的喷漆,提高涂装的效率;能够降低运输和支撑的成本。本文对临时支撑进行了合理的设计和结构分析,在静力分析中进行了各种荷载组合,得出构件的等效应力场和等效位移场,提出了该结构的变形最大点和薄弱环节,对于整个结构的安全设计具有参考价值。     

高速公路噪声防治措施分析

论述了高速公路噪声防治工作目标和实施原则,分析了高速公路现有噪声防治措施的特点和适用条件,提出了噪声防治措施方案比选方法,在高速公路的规划、设计中得到了较好的应用。     

2006年度国际市场最大200家设计公司市场分析

介绍了美国<工程新闻记录>周刊所做的2006年度200家最大设计公司的排名情况,并对这一排名进行了分析和对比.2006年度200强设计公司的国际市场营业额与去年相比增长了25.6%.中国大陆进入200强的设计公司依然维持在2005年的13家,营业额比去年也有了很大的增长,但相对于国际市场的快速增长,中国的份额仍有待提高.