【作者】 王玥；

【导师】 殷志祥；

【作者基本信息】 辽宁工程技术大学 ， 岩土工程， 2006， 硕士

【摘要】 蠕变是材料最典型的,也是最基本的一种变形方式。蠕变指的是材料在外荷载保持恒定不变的条件下,变形却随着时间的推移不断增大的一种力学现象。索膜结构建筑采用的膜材通常是一种高强、柔软的织物复合材料,它在不太高的温度,甚至在室温下有明显的粘弹性蠕变现象。作为一种建筑用材,人们关注其在一定环境条件下的使用性能和耐久性,结构受长期荷载作用可发生过渡的蠕变,造成预应力损失而引起膜面发生皱褶现象,导致整体结构的承载力下降,甚至达到破坏。研究膜材受载时依赖于时间的蠕变性能,以便在工程设计中提供设计应力,在设计时要预先加入预调装置,便于在几年后对发生了松弛的膜面进行再次张力导入,这对膜材在建筑结构领域的应用具有重要的意义。目前,在对索膜结构研究的领域中,主要研究结构的找形分析、荷载分析和剪裁分析,使用了不同的研究手段和方法,但都没有涉及到蠕变因素的影响,没有考虑到索膜结构的蠕变性能。查阅大量的参考资料表明,对索膜结构蠕变性能的研究很少,由于缺少参考资料,所以本文是借鉴类似膜材料的其它复合材料的蠕变性能,来研究索膜结构的蠕变性能。本文的研究就是以非线性有限元法为基础,利用描述粘弹性蠕变行为的Burgers四元件模型来描述索膜结构的蠕变性能,根据以上推导的有限元列式,建立了考虑蠕变影响的有限元方程,同时,还利用Ansys软件对索膜结构进行蠕变分析,得出了理想的蠕变曲线,为考虑蠕变影响的应力应变分析提供了科学依据,用实例证明了理论研究的必要性。更多还原

【Abstract】 Creep is the most typical and basal distortion fashion of material. Under invariable temperature and outside force, distortion increases gradually with time increase , viz. creep phenomenon. which affects structure use value, so study on creep performance of cable-membrane structure is quite important. Membrane material that used in cable-membrane structure is a sort of high strength、tender fabric composite material, under not high temperature, even under room temperature, it represents obvious viscoelastic creep phenomenon. As a sort of architecture material, people attent its using performance and wear under certain condition, structure endure long loads can occur transition creep phenomenon, lead stress loss that arose membrane occur drape, and that result in the whole structure carrying capacity descend, even reach destroy. Study membrane material creep performance, in order to offer design stress during project design. During design need to join advance mix setting, that can carry strain guide again on flabby membrane after years, that lead membrane material using in cable-membrane structure has important meaning. At present, during cable-membrane structure investigative field, mainly investigate structure form-finding analysis, static analysis and clipping analysis, use different study means and measure, but not come down to creep factor infection, not considering cable-membrane structure creep performance. Consult large numbers of reference data indicate, study on cable-membrane structure creep performance is very few., due to lace reference data, so this paper use for reference other composite material like membrane material creep performance, study cable-membrane structure creep performance. This paper describes creep performance of cable-membrane structure by using Burgers four component model which describes viscoelastic creep, based on the above equations using Fortran language, educes finite element equation that considers creep affect. At the same time, this paper uses Ansys software analyses creep performance of cable-membrane structure, educes perfect creep curve, which provides science foundation of stress-strain analysis for considering creep affect.更多还原