张拉成形曲面的应力松弛分析

发布时间：2018-01-20 12:39

本文关键词： 张拉成形曲面广义Maxwell模型 PVC膜材黏弹性模型应力松弛　出处：《建筑结构学报》2015年05期 　论文类型：期刊论文

【摘要】：对膜结构施工中由裁剪片拼接张拉形成的膜面进行应力松弛分析,考察膜面应力随时间逐渐减小的变化规律。考虑膜材材料和几何双重非线性,采用广义Maxwell黏弹性模型建立积分型本构方程,推导增量本构方程,编制非线性有限元程序实现成形曲面的应力松弛数值分析过程。对聚氯乙烯(PVC)膜材进行了不同初始应力水平下的单轴应力松弛试验和不同应力比下的双轴应力松弛试验,用5单元的广义Maxwell黏弹性模型对试验数据拟合,确定了膜材本构方程的黏弹性参数。进行十字形膜片的加载及应力松弛试验,对其试验过程进行数值分析,结果表明试验结果与数值分析结果基本一致,验证了成形曲面黏弹性数值分析方法的可行性。对PVC膜材马鞍形曲面算例进行黏弹性分析,结果表明,马鞍形曲面在张拉完成4 d后,膜面平均应力降低了44%。
[Abstract]:The stress relaxation analysis of the membrane surface formed by the splicing tensioning of the cutting pieces in the construction of membrane structure is carried out, and the variation law of the membrane surface stress gradually decreasing with time is investigated. The material and geometric nonlinearity of the membrane material are considered. The integral constitutive equation is established by using the generalized Maxwell viscoelastic model and the incremental constitutive equation is derived. Development of nonlinear finite element program for numerical analysis of stress relaxation of forming surface. Uniaxial stress relaxation tests with different initial stress levels and biaxial stress relaxation tests with different stress ratios were carried out. The viscoelastic parameters of the constitutive equation of the membrane were determined by fitting the test data with the generalized Maxwell viscoelastic model of 5 elements. The loading and stress relaxation tests of the cross-shaped diaphragm were carried out. The numerical results show that the experimental results are in good agreement with the numerical results. The feasibility of viscoelastic numerical analysis method for forming surface is verified. The viscoelastic analysis of saddle curved surface of PVC membrane is carried out. The results show that the saddle curved surface is completed 4 days after tension. The average stress of the film surface is reduced by 44%.
【作者单位】：鲁东大学土木工程学院;同济大学建筑工程系;
【基金】：国家自然科学基金项目(50778129) 鲁东大学博士科研启动基金项目(LY2014029)
【分类号】：TU38
【正文快照】： 0引言膜结构通过对膜材和索施加预张力使之具有刚度从而抵抗外荷载作用,结构的刚度由其几何形状和张拉预应力决定。施工中,将裁剪分析得到的平面膜片拼接张拉到固定边界形成平衡曲面,该曲面称为成形曲面。由于膜材的黏弹特性,导致成形曲面的膜面张力因应力松弛而降低,影响结构

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