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为了研究核电工程中钢板混凝土组合墙的承载能力以及设计参数对承载力的影响,以4个核电工程中钢板混凝土组合墙的轴压试验为基础,采用ABAQUS建立钢板混凝土组合墙的有限元模型,模型中混凝土、钢板和栓钉均采用实体模型模拟,考虑了材料非线性和钢板焊接残余应力等。研究了栓钉的受力机理,模拟了试件中钢板的屈曲变形,分析不同参数如钢板与混凝土的强度、距厚比和含钢量对承载力的影响。分析结果表明:有限元模型计算结果与试验结果吻合较好,栓钉在受力过程中始终处于弹性受力状态,混凝土强度对承载力影响最大,距厚比对钢板的屈曲影响较大,较小的距厚比能保证钢板与混凝土协同工作。 相似文献
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为了考虑钢板屈曲对双钢板-混凝土组合(DSCC)剪力墙的轴压承载力的影响,该文首先以4个组合墙的轴压试验为基础,采用ABAQUS建立DSCC剪力墙的有限元模型。模型中混凝土采用实体单元,钢板采用壳单元,剪力连接件采用非线性弹簧单元SpringA,并考虑了材料非线性和钢板初始缺陷。在验证有限元模型后,研究了不同参数对钢板屈曲的影响,得到了钢板屈曲应力的计算公式。分析结果表明:当钢板出现局部横向贯通屈曲时,破坏模式为屈曲位置的混凝土压碎;当钢板未发生屈曲时,破坏模式为钢板屈服;墙侧面钢板宽度较小时,侧面钢板不会发生屈曲。最后,基于钢板屈曲分析以及构件极限状态下的应力状态分析,提出了新的DSCC剪力墙的轴压承载力计算方法,引入了钢板屈曲的影响。结构表明:对比规范JGJ/T 380―2015采用的计算公式,该文提出的计算方法具有更高的精度和稳定性,可用于DSCC剪力墙的深入研究以及工程设计。 相似文献
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建立了计及悬架系统钢板弹簧刚度和减振器阻尼非线性的整车八自由度模型。用统计线性化方法求出了系统在路面随机激励下的响应,并将计算结果与实验值和时域法模拟结果进行了比较。结果表明统计线性化方法与实验值吻合较好,比时域法的精度高,是进行车辆非线性分析的有效方法。 相似文献
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In this study, the resistance of liquefied-petroleum gas (LPG) tanks produced from carbon steel sheet metal of different thicknesses has been investigated by bursting pressure experiments and non-linear Finite Element Method (FEM) method by increasing internal pressure values. The designs of LPG tanks produced from sheet metal to be used at the study have been realized by analytical calculations made taking into consideration of related standards. Bursting pressure tests have been performed that were inclined to decreasing the sheet thickness of LPG tanks used in industry. It has been shown that the LPG tanks can be produced in compliance with the standards when the sheet thickness is lowered from 3 to 2.8mm. The FEM results have displayed close values with the bursting results obtained from the experiments. 相似文献
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按新、旧两种剪切试验标准对相同材料进行了大量试验研究。结果表明,按新标准进行的试验,结果准确、可靠,数据稳定性好,更真实地反映出材料的特性。 相似文献
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The tensile dynamic mechanical properties of paper sheets with densities between 300 and 1000 kg m–3 have been measured at room temperature in the frequency range 0.1 to 10 Hz. Two series of sheets have been investigated; one which had been restrained during drying and the other which had been allowed to shrink freely. In general, paper was found to be a non-linear viscoelastic material. The dynamic modulus decreased and the mechanical loss factor increased as the strain amplitude of the applied sinusoidal deformation was increased. The non-linear character of paper was more pronounced at lower sheet densities. The modulus increased strongly with increasing sheet density and was always higher for sheets that had been restrained during drying. The sheets were anisotropic and the ratio of the modulus in the machine direction (MD) to that in the cross-direction (CD) was of the order of 2 to 3.5 depending on the density and the drying conditions. The mechanical loss factor (extrapolated to zero strain amplitude) decreased with increasing sheet density and was always higher in the CD than in the MD. The freely dried sheets were characterized by a higher value of the mechanical loss factor, tan , than sheets that had been restrained during drying. It is suggested that the influence of the sheet density and the drying restraints on the dynamica mechanical properties of paper is associated with interfibre friction and/or bending and shearing of the cellulose fibres. 相似文献
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Linear stability of non-Newtonian annular liquid sheets 总被引:1,自引:0,他引:1
Summary This paper reports a linear stability analysis of a non-Newtonian annular liquid sheet that is surrounded by nonviscous fluids in relative axial motion to it. It is shown that for a stress free basic flow the dispersion relation giving the absolute and convective instability mechanisms can be immediately obtained from the dispersion relation for a Newtonian sheet by introducing a wavenumber dependent viscosity. The stability behavior of the sheet is investigated numerically by a continuation algorithm, by which the solution branches of the dispersion relation, relevant for the stability information, can be traced. The results give a stability picture which covers the whole range of annular sheets from the cylindrical jet to the plane liquid curtain. 相似文献
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A. V. Clark C. M. Fortunko M. G. Lozev S. R. Schaps M. C. Renken 《Research in Nondestructive Evaluation》2013,24(3):165-182
Abstract An electromagnetic-acoustic transducer (EMAT) system was used in conjunction with a “sampled” CW signal-processing method to generate, receive, and process longitudinal and shear waves in thin steel sheets. Using the system, swept-frequency measurements were made up to 7.5 MHz. To relate the measurements to sheet steel formability, a dimensionless frequency ratio, K, was computed from the resonant frequencies. From theoretical considerations, K should be related to a measure of steel sheet formability, r . This parameter is traditionally measured by plastically deforming uniaxial tension specimens. Good correlation was found between K and r for a set of steel sheet representative of those typically used to produce automobile body parts. 相似文献
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This paper considers two novel free boundary problems that emerge from modelling processes basic to steel manufacture.The first process concerns the spray cooling of hot steel sheet during the process of continuous casting. Here, an important practical consideration is the non-monotonicity of the measured heat transfer from the steel as a function of the steel temperature. In order to understand this phenomenon, a two-phase flow model is written down for the heating and vapourisation of the water spray. This model relies on a microscale analysis of droplet vapourisation and, in a steady state, it reduces to a coupled system of nonlinear ordinary differential equations for the spray temperature and water content. This system predicts the conditions for the existence or otherwise of a free boundary separating the two-phase region from a dry vapour layer close to the steel plate.The thickness of this vapour layer is determined by the solution of a generalised Stefan problem. The second process concerns the macroscopic modelling of pig iron production in blast furnaces. In the simplest scenario, the blast furnace may be roughly divided into a porous solid region. overlaying a hot high pressure gaseous zone. The gas reacts with the solid in a thin "intermediate region" at the base of the solid region and it is in this intermediate region that the pig iron is produced. A free boundary model is proposed for the location of the intermediate region and its stability is investigated. 相似文献
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Solar selectivity, with emphasis on a high solar absorptance and a low thermal emittance, was measured for black molybdenum films prepared by a chemical conversion process. The best values of the solar absorptance (0.88) and the thermal emittance (0.20) were achieved by optimizing the preparation parameters, e.g. the bath composition, the deposition temperature and the immersion time. The films deposited onto galvanized steel sheet and zinc-plated mild steel sheet show high adherence and good thermal stability at elevated temperatures (250 °C). 相似文献
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A.D.Fitt J.R.Ockendon C.P.Please 《工程数学学报》2004,21(3):285-306
This paper considers two novel free boundary problems that emerge from modelling processes basic to steel manufacture. The first process concerns the spray cooling of hot steel sheet during the process of continuous casting. Here, an important practical consideration is the non-monotonicity of the measured heat transfer from the steel as a function of the steel temperature. In order to understand this phenomenon, a two-phase flow model is written down for the heating and vapourisation of the water spray. This model relies on a microscale analysis of droplet vapourisation and, in a steady state, it reduces to a coupled system of nonlinear ordinary differential equations for the spray temperature and water content. This system predicts the conditions for the existence or otherwise of a free boundary separating the two-phase region from a dry vapour layer close to the steel plate.The thickness of this vapour layer is determined by the solution of a generalised Stefan problem. The second process concerns the macroscopic modelling of pig .iron production in blast furnaces. In the simplest scenario, the blast furnace may be roughly divided into a porous solid region overlaying a hot high pressure gaseous zone. The gas reacts with the solid in a thin “intermediate region“ at the base of the solid region and it is in this intermediate region that the pig iron is produced. A free boundary model is proposed for the location of the intermediate region and its stability is investigated. 相似文献