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在较为复杂的、刚度不均匀的结构抗震计算中,对主振型出现在高阶振型的现象进行了分析探讨。 相似文献
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在较为复杂的、刚度不均匀的结构抗震计算中 ,对主振型出现在高阶振型的现象进行了分析探讨 相似文献
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不等跨两跨连续弹性支座梁的振动计算问题,目前我国有关规范和文献尚缺乏这方面的内容。介绍了对这种梁振动的一种简便计算方法,该方法概念清楚,计算简便,易于有关人员掌握,通过多项实际工程应用表明,能很好地满足控制工程振动的需要,可供设计工程师和有关人员在工程设计和研究中参考应用。 相似文献
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一端刚接不动支座另一端简支弹性支座梁的振动计算问题,目前我国有关规范和规程尚缺乏这方面的内容。介绍了对这种支座条件梁振动的一种简便计算方法,可以计算梁前三个振型的自由振动和强迫振动,该方法概念清楚,计算简便,易于掌握,通过实际工程应用表明,能较好地满足工程振动的需要。 相似文献
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为评估高层建筑风振的舒适度,应建立简单实用的结构风振响应计算方法。而我国GB 50009—2012《建筑结构荷载规范》的高层建筑顺风向风振响应简化计算方法没有考虑二阶振型的贡献。基于准定常理论,采用频域法进行了考虑二阶振型贡献的高层建筑顺风向风致响应评估,并分析了二阶振型对结构风致响应的贡献。结果表明:二阶振型对高层建筑顺风向动力位移响应的贡献一般在2%以内,但对顺风向动力加速度响应的贡献最大能达到18%。在评估结构顺风向风振加速度响应时,二阶振型的贡献不能忽略。在此基础上,推导了考虑二阶振型的对称等截面高层建筑顺风向风振响应简化计算方法。将此简化方法得到的结果与频域法和规范公式得到的结果进行对比,其误差在5%以内,表明简化公式具有较好的精度和适用性。 相似文献
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讨论了在水平地震作用计算中的高振型影响,从而对水平地震作用计算方法提出了有意义的调整,并且通过对简化模型的分析,为工程结构计算中的振型选取提出了几点建议。 相似文献
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对目前计算预弯组合梁极限抗弯强度时存在的问题进行了讨论,提出了相对比较准确的考虑弹塑性影响的极限抗弯强度的计算方法。本文计算公式物理概念明确,使用方便,其计算结果与试验值吻合较好。 相似文献
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介绍了有限元ANSYS中壳元模型的建立步骤,并利用有限元ANSYS程序对简支梁屈曲荷载进行了求解,通过理论分析与有限元结果的比较,验证了有限元ANSYS程序计算结果的正确性,并为外形和受力复杂的简支杆件的稳定承载能力的计算提供了参考依据。 相似文献
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现今对结构模态的测试大都集中于加速度响应或速度响应,对其他响应做出研究的较少。用简支梁在环境激励下的倾角数据进行模态分析,先通过理论分析,再通过试验方法分别得到简支梁的模态参数。最终发现两者的结果大致相同,因此通过简支梁的倾角数据能够测试模态参数,拓展了倾角仪在工程中的应用范围。 相似文献
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G. Russo 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2009,24(1):103-111
In this paper, a new approach for a quantitative assessment of the Geological Strength Index (GSI, Hoek, E., Kaiser, P.K., Bawden, W.F., 1995) is proposed. In particular, on the basis of the conceptual affinity of the GSI with the Joint Parameter (JP) used in the RMi (Rock Mass index, Palmstrom, 1996), a relationship between the two indexes is derived and exploited in order to obtain a reliable, quantitative assessment of the GSI by means of the basic input parameters for the determination of the RMi (i.e. the elementary block volume and the joint conditions). In this way, the user has the possibility of applying and comparing two truly independent approaches for the determination of the GSI: the traditional qualitative “Hoek’s chart”, mainly based on the degree of interlocking of rock mass, and the proposed quantitative assessment method, mainly based on the fracturing degree of a rock mass. On the basis of such a double-estimation, a definitive “engineering judgement” can be made more rationally. The new approach facilitates as well the implementation, from one side, of the probabilistic approach for managing the inherent uncertainty and variability of rock mass properties and, from the other, of the RMi system as empirical method for tunnel design. Given the complementarities of the two indexes, the proposed approach appears to be very promising. An example application is presented to illustrate the high potentiality of the new method. 相似文献
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为保证预应力混凝土结构正截面承载力的可靠性,推导了全面考虑次内力影响的预应力混凝土框架梁承载力计算公式,并对在特定预应力筋线型下的单层单跨预应力混凝土框架梁的相关算例进行了讨论。得出了梁柱线刚度比是影响次轴力的一项重要指标,当柱梁线刚度比达到18时,对框架梁跨中承载力影响达到5.67%,不考虑次轴力影响是不合理不安全的结论。 相似文献
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《Thin》2014
Buckling behaviors of web-posts in a cellular steel beam at elevated temperatures in a fire were studied using the Finite Element Method (FEM) analysis and available analytical models. The buckling temperatures obtained by the analytical models differed greatly to those obtained from the FEM simulation. Among these analytical models, the buckling temperature obtained through the strut model based on BS5950-1 agreed with the FEM result the best. It is more reasonable to take the width of the compression stress band in the web-post as the effective width of the strut. Numerical parametric studies showed that the width of the compression stress band varied with the opening diameter, the opening distance and the web thickness. A simplified method was proposed to calculate the effective width of the strut. The accuracy of the strut model integrating the new effective width was validated against the FEM simulations. The obtained buckling temperature of the web-post using the modified strut model agreed well with the FEM simulation result. 相似文献