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从实例出发,对比前后采用的认为解决方案确定的传统方法与认为解决方案不确定而寻求解决方案的适应型方法两种方法,介绍了BOSS软件项目管理以有效、服务型的沟通为核心的适应型方法,同时该方法也对企业项目化管理十分有效。 相似文献
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《智能建筑与城市信息》2010,(8):97-98
美国康普推出新型无线基础设施解决方案
近日,美国康普旗下的企业解决方案部门宣布推出新型Wired for Wireless^TM解决方案,该解决方案有助于在建设阶段即消除室内无线通信的信号盲区或死区,为新建筑和园区业主及开发商提前布局提供必要的基础设施。 相似文献
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针对前期研究中提出的三剪能量本构模型,基于塑性位势理论,详细推导其在FLAC3D中的增量迭代格式,并编制相应的UDM接口程序。为了验证程序的正确性,考虑到三剪能量准则常规三轴情况下退化为Mohr-Coulomb准则,分别采用三剪能量本构模型和FLAC3D内嵌的Mohr-Coulomb模型数值模拟试样的常规三轴试验。计算结果显示,两种模型给出的结果几乎完全一样,从而验证计算格式和程序的正确性。最后,研究三剪能量本构模型的工程应用,分别采用Prandtl理论解、Mohr-Coulomb模型和三剪能量本构模型计算地基的极限承载力,计算结果表明,由于Prandtl理论解是基于Mohr-Coulomb准则建立的,且Mohr-Coulomb准则不考虑中间主应力的影响,而三剪能量准则考虑了中间主应力的影响,因此,Prandtl理论解和Mohr-Coulomb模型均偏于保守,其计算的极限承载力要比三剪能量本构模型计算结果偏小。 相似文献
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研究了由三个拟线性退化抛物型方程通过非线性项耦合而得到的一类拟线性退化抛物方程组解的性质.该方程组描述了一个具有三种连续介质的燃烧过程及热扩散过程.通过运用比较定理和构造上、下解方法,建立了该方程组解的整体存在和有限爆破的充分条件.由此得到,当反应项和扩散项的指数满足不同条件时,方程组的解具有不同的性质. 相似文献
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A novel run-around membrane energy exchanger (RAMEE) system is designed, built, and tested for heating, ventilating, and air-conditioning applications. The RAMEE system consists of two counter-cross-flow liquid-to-air membrane energy exchangers, one located in the supply and the other in the exhaust air streams of a building. Inside each exchanger, a micro-porous membrane separates the air and desiccant solution streams. This membrane allows heat and water vapor exchange between the two streams. The RAMEE system thus exchanges sensible and latent energy between the supply and exhaust air streams by using a desiccant solution as the energy carrier that is pumped in a loop between the two exchangers. The RAMEE performance is evaluated by testing the system with various air and desiccant solution flow rates during standard summer and winter operating conditions. During summer test conditions, the total system effectiveness increases with increasing desiccant flow rate, but decreases as the air flow rate increases. Under winter test conditions, the total effectiveness changes little with changes in the air and desiccant flow rates. For some test conditions, the maximum total effectiveness of the system is between 50 and 55%. The effectiveness data are compared to available correlations and reasons for discrepancies are discussed. 相似文献
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A pier, jack arch, and segmental arch will be analyzed using a minimization of potential energy procedure. The method involves creating an energy equation that describes the structure in terms of local displacements. The energy equation will be set up in a linear form so that it can utilize linear programming methods of minimization. The minimization routine will be subject to a number of constraints used to enforce the end conditions of the arch at the abutments and constraints against interpenetration and sliding of adjacent blocks, and then solved for both the primal and dual solutions. The normal forces which are necessary to determine the frictional energy dissipated due to a sliding failure will be derived from the slack of the dual solution. The primal solution will result in either an unbounded solution, indicating an unstable structure, or a solution of zero, indicating a stable structure. This information will be used to solve for a critical value of stability for a particular unknown. 相似文献
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In this paper, new assumptions are made to determine the energy dissipation capacity of the basic folding mechanism. The basic folding mechanism, introduced by Wierzbicki and Abramowiciz is an intelligent mathematical imitation of the real crumpling process for simple structural sections. A contribution factor for some part of energy absorption and the new concept of varying rolling radios, based on minimizing instantaneously applied load, are utilized to enrich the old analytical solution. A set of finite element analyses on the axial collapse of square boxcolumns with various cross sections and width to thickness ratios, has been performed to verify the proposed analytical solution vs. the original mathematical model. An excellent agreement in the amount of energy dissipation has been achieved in most cases. 相似文献
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This paper presents a study on the flattening behavior of angle-section beams of finite length subjected to uniformly distributed transverse loads. Analytical solutions for static instabilities of angle-section beams when they are bent about their weak axis are derived using energy methods. The basic assumptions used in the present study are that the total strain energy of an angle-section beam subjected to a uniformly distributed load can be simplified into a two-stage process. One is the bending response of the two legs behaving as the plate; the other is the bending response as a beam with flattened section. The nonlinear instability is derived by applying the minimum potential energy principle and the corresponding static critical moments associated with the section flattening-induced buckling are determined. To validate the analytical solution developed, nonlinear finite element analyses are also conducted. Good agreement between the present solution and the FEA results is demonstrated. 相似文献
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太阳能光伏发电是近年来新兴的环保、节能、清洁的可再生能源,开发利用太阳能对于解决能源紧缺、环境污染问题至关重要.就如何利用太阳能光伏发电解决路灯照明设计问题作了重点介绍,依据国家有关规范、标准,按照设计流程逐步介绍了系统构成,设计方法,经验数据、计算公式等内容,旨在有助于推动规模化太阳能光伏发电照明方面的开发利用,以获取更多、更好的经济、社会、环境效益. 相似文献
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块体间的相互碰撞、滑移均涉及到摩擦力的问题,但原有的三维有限元/离散元(FEM/DEM)并未考虑摩擦力的作用,为解决这一问题,首先论述三维FEM/DEM中基于势的接触力,指出势是对嵌入及接触所存储能量的表征,势越大表示嵌入量越大,接触所存储的能量越大。然后,在原有三维FEM/DEM中加入经典的库仑摩擦,使得原有三维FEM/DEM可以考虑摩擦力。最后,通过有解析解的斜面滑块算例和拱桥垮塌算例验证实施库仑摩擦的正确性,结果表明斜面滑块算例的数值解与解析解很好地吻合;而拱桥垮塌算例表明FEM/DEM可以解决复杂的工程问题。 相似文献